From owner-recombination@net.bio.net Tue Apr 01 23:00:00 1997 Path: biosci!SELWAY.UMT.EDU!wr From: wr@SELWAY.UMT.EDU (Rong Wang) Newsgroups: bionet.molbio.recombination Subject: suicide vectors Date: 2 Apr 1997 13:53:16 -0800 Organization: The University of Montana Lines: 5 Sender: daemon@net.bio.net Distribution: world Message-ID: <3342C682.55F0@selway.umt.edu> NNTP-Posting-Host: net.bio.net I am looking for suicide vectors for E. coli. Any information and product suggestions are most welcome. Angelika Longacre longacre@selway.umt.edu From owner-recombination@net.bio.net Thu Apr 03 23:00:00 1997 Newsgroups: bionet.molbio.recombination Path: biosci!rutgers.rutgers.edu!gatech!EU.net!news-peer.gsl.net!newsfeed.nacamar.de!azure.xara.net!xara.net!uknet!usenet1.news.uk.psi.net!uknet!uknet!bcc.ac.uk!news From: Paul Wells Subject: PRACTICAL COURSE IN GENETIC ENGINEERING Message-ID: <1997Apr3.141908.28273@ucl.ac.uk> Date: Thu, 3 Apr 1997 14:19:08 GMT Organization: University College London Lines: 33 A one week practical course designed to teach the basic techniques in genetic engineering will be held from 16th-20th June 1997 at the Dept. of Biochemistry and Molecular Biology University College London. A "hands on" approach will enable scientists from higher education and industry, clinicians and research workers who have had no practical experience of recombinant DNA technology to set up such techniques in their own laboratories. Techniques to be covered will include, Southern hybridisation DNA sequencing, PCR, and analysis of cloned DNA using enzyme restriction mapping. Supplemented with some lectures. Course fee 900 pounds sterling (750 for full time postgraduate students) exclusive of accomodation. Bed and breakfast accomodation for the period of the course can be provided in a local hall of residence for 102 pounds sterling from Sunday 15th June until Saturday 21st June. Write for application forms and further details to: Dr. John Ward Department of Biochemistry & Molecular Biology University College London Gower Street London WC1E 6BT Fax: 0171 380 7193 Or e-mail either:- j.ward@biochem.ucl.ac.uk p.wells@ucl.ac.uk From owner-recombination@net.bio.net Sat Apr 05 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET (Graham Dellaire) Newsgroups: bionet.molbio.recombination Subject: Re:suicide vectors Date: 6 Apr 1997 08:26:05 -0700 Organization: McGill Div. of Experimental Medicine Lines: 15 Sender: daemon@net.bio.net Distribution: world Message-ID: <3347BED6.1472@odyssee.net> Reply-To: dellaire@odyssee.net NNTP-Posting-Host: net.bio.net Hello Angelika I am aware of one such vector. It contains a Gata-1 gene from the mouse. The Gata 1 gene is toxic to E.coli. Disruption of the Gata-1 gene leads to rescue of the bacterium, ex. by cloning into the vector. Look for the following reference Trudel P. Provost S. Massie B. Chartrand P. Wall L. pGATA: a positive selection vector based on the toxicity of the transcription factor GATA-1 to bacteria. Biotechniques. 20(4):684-93, 1996 Apr. Angelika From owner-recombination@net.bio.net Sun Apr 06 23:00:00 1997 Path: biosci!rutgers.rutgers.edu!gatech!csulb.edu!hammer.uoregon.edu!azure.xara.net!xara.net!dispatch.news.demon.net!demon!cpk-news-hub1.bbnplanet.com!cam-news-hub1.bbnplanet.com!news.bbnplanet.com!uunet!in3.uu.net!136.142.185.26!newsfeed.pitt.edu!newsflash.concordia.ca!feed.umontreal.ca!cyclone.ERE.UMontreal.CA!szat From: szat@ERE.UMontreal.CA (Szatmari George) Newsgroups: bionet.molbio.recombination Subject: Re: suicide vectors Date: 7 Apr 97 20:59:05 GMT Organization: Universite de Montreal Distribution: world Message-ID: References: <3347BED6.1472@odyssee.net> NNTP-Posting-Host: cyclone.ere.umontreal.ca Lines: 20 Regarding suicide vectors in gram neg's, I am aware of several: ones based on a thermosensitive plasmid replicon (pSC101) refer to J. Bact 178 p 894 (1996) ones based on a lambda dv plasmid, which can be inhibited by the lambda repressor refer to Flinn et al J. Bact 171 p 2241-3 (1989) my favorite: based on the R6K replicon, which requires the pi protein to be supplied in trans refer to Skzrypek et et Plasmid 29 p 160-3 (1993) (one of many refs) ones based on a lethal gene (sacB) whos expression is lethal to coli: see Mobley et al, Mol. Micro 10 pp143-55, 1993 Hope this helps George Szatmari Dept de microbiologie, Univ de Montreal From owner-recombination@net.bio.net Tue Apr 08 23:00:00 1997 Path: biosci!daresbury!uninett.no!hermod.uio.no!nntp.uio.no!newsfeed.nacamar.de!rill.news.pipex.net!pipex!howland.erols.net!cam-news-hub1.bbnplanet.com!news.bbnplanet.com!news.idt.net!usenet.logical.net!news.dal.ca!news.nstn.ca!newsflash.concordia.ca!news.mcgill.ca!news From: mdty@musica.mcgill.ca Newsgroups: bionet.molbio.recombination Subject: Conference June 5-7, 1997 [conf.97] (1/1) Date: 9 Apr 1997 14:10:40 GMT Organization: McGill University Computing Centre Lines: 36 Message-ID: <5ig810$t97@sifon.cc.mcgill.ca> NNTP-Posting-Host: 198.168.147.137 X-Newsreader: SPRY News 3.03 (SPRY, Inc.) begin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`T*,38U,"!#961A NNTP-Posting-Host: 198.168.147.137 X-Newsreader: SPRY News 3.03 (SPRY, Inc.) Conference on: From DNA Damage to Cell Death: The Role of Nuclear Structure in the Response to Cancer Therapy. June 5-7, 1997 Montreal, Canada. From owner-recombination@net.bio.net Tue Apr 08 23:00:00 1997 Path: biosci!daresbury!uninett.no!nntp.uio.no!news.maxwell.syr.edu!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!ais.net!uunet!in3.uu.net!136.142.185.26!newsfeed.pitt.edu!newsflash.concordia.ca!news.mcgill.ca!news From: mdty@musica.mcgill.ca Newsgroups: bionet.molbio.recombination Subject: conference June 5-7, 1997 Date: 9 Apr 1997 14:30:55 GMT Organization: McGill University Computing Centre Lines: 52 Message-ID: <5ig96v$t97@sifon.cc.mcgill.ca> NNTP-Posting-Host: 198.168.147.137 X-Newsreader: SPRY News 3.03 (SPRY, Inc.) Sorry about the earlier posting. Here is the decoded informations. Conference: From DNA Damage to Cell Death: The Role of Nuclear Structure in the Response to Cancer Therapy June 5-7, 1997 Montreal, Canada Topic include: * Nuclear Matrix Organization and Radiation/Drug Sensitivity * Nuclear Structure in Relation to the Formation of Chromosome Aberrations * Nuclear Organization, DNA Repair and Apoptosis *Nuclear Factors Influencing DNA Damage Heterogeneity Preliminary list of invited speakers: Joel S. Bedford, Colorado State University Charles Geard, Columbia University Walter N. Hittelman, University of Texas M.D. Anderson Cancer Center George Iliakis, Thomas Jefferson University Peter J. Johnston, University of British Columbia Cancer Research Centre Marc-Edouard Mirault, Centre Hospitalier de l'Universite Laval Nancy Oleinick, Case Western Reserve School of Medicine Peggy Olive, University of British Columbia Cancer Research Centre Guy Poirier, Centre Hospitalier de l'Universite Laval Joseph Roti Roti, Washington University, St. Louis Jeffrey L. Schwartz, University of Washington, Seattle Information: Drs. Shirley Lehnert and Terry Chow Radiation Oncology, McGill University Montreal General Hospital 1650 Cedar Avenue Montreal, Quebec H3G 1A4 Canada Tel: (514) 937-6011 ext. 4161/4179 Fax: (514) 934-8220 e-mail: mdle@musica.mcgill.ca or mdty@musica.mcgill.ca Registration available upto three weeks befor conference date. For Information contact: Diana Sarai Coordinator Tel: (514) 398-6268 e-mail: sarai@medcor.mcgill.ca From owner-recombination@net.bio.net Wed Apr 09 23:00:00 1997 Newsgroups: bionet.molbio.recombination Path: biosci!daresbury!uninett.no!nntp.uio.no!newsfeeds.sol.net!europa.clark.net!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!rill.news.pipex.net!pipex!uknet!usenet1.news.uk.psi.net!uknet!uknet!bcc.ac.uk!news From: Paul Wells Subject: PRACTICAL COURSE IN GENETIC ENGINEERING Message-ID: <1997Apr10.101900.65433@ucl.ac.uk> Date: Thu, 10 Apr 1997 10:19:00 GMT Organization: University College London Lines: 33 A one week practical course designed to teach the basic techniques in genetic engineering will be held from 16th-20th June 1997 at the Dept. of Biochemistry and Molecular Biology University College London. A "hands on" approach will enable scientists from higher education and industry, clinicians and research workers who have had no practical experience of recombinant DNA technology to set up such techniques in their own laboratories. Techniques to be covered will include, Southern hybridisation DNA sequencing, PCR, and analysis of cloned DNA using enzyme restriction mapping. Supplemented with some lectures. Course fee 900 pounds sterling (750 for full time postgraduate students) exclusive of accomodation. Bed and breakfast accomodation for the period of the course can be provided in a local hall of residence for 102 pounds sterling from Sunday 15th June until Saturday 21st June. Write for application forms and further details to: Dr. John Ward Department of Biochemistry & Molecular Biology University College London Gower Street London WC1E 6BT Fax: 0171 380 7193 Or e-mail either:- j.ward@biochem.ucl.ac.uk p.wells@ucl.ac.uk From owner-recombination@net.bio.net Wed Apr 09 23:00:00 1997 Newsgroups: bionet.molbio.recombination Path: biosci!agate!howland.erols.net!europa.clark.net!news.maxwell.syr.edu!rill.news.pipex.net!pipex!uknet!usenet1.news.uk.psi.net!uknet!uknet!bcc.ac.uk!news From: Paul Wells Subject: Practical introduction to genetic engineering course Message-ID: <1997Apr10.133521.60390@ucl.ac.uk> Date: Thu, 10 Apr 1997 13:35:21 GMT Organization: University College London Lines: 35 A one week practical course designed to teach the basic techniques in genetic engineering will be held from 16th-20th June 1997 at the Dept. of Biochemistry and Molecular Biology University College London. A "hands on" approach will enable scientists from higher education and industry, clinicians and research workers who have had no practical experience of recombinant DNA technology to set up such techniques in their own laboratories. Techniques to be covered will include, Southern hybridisation DNA sequencing, PCR, and analysis of cloned DNA using enzyme restriction mapping. Supplemented with some lectures. Course fee 900 pounds sterling (750 for full time postgraduate students) exclusive of accommodation. Bed and breakfast accommodation for the period of the course can be provided in a local hall of residence for 102 pounds sterling from Sunday 15th June until Saturday 21st June. For further information visit our web site Write for application forms to: Dr. John Ward Department of Biochemistry & Molecular Biology University College London Gower Street London WC1E 6BT Fax: 0171 380 7193 Or e-mail either:- j.ward@biochem.ucl.ac.uk p.wells@ucl.ac.uk From owner-recombination@net.bio.net Sat Apr 12 23:00:00 1997 Path: biosci!daresbury!uninett.no!nntp.uio.no!newsfeed.nacamar.de!news-feed.inet.tele.dk!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!news-peer.sprintlink.net!news.sprintlink.net!sprint!howland.erols.net!news.starnet.net!news.starnet.net!axb.slu.edu!news From: Nanda Somarajan Newsgroups: bionet.molbio.recombination Subject: subscribe Date: Sat, 12 Apr 1997 14:51:33 -0500 Organization: Saint Louis University Lines: 1 Message-ID: <334FE7C5.5992@slu.edu> NNTP-Posting-Host: 165.134.21.45 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01 (Win95; I) CC: somarank@slu.edu subscribe bionet-news.bionet.molbio.recombination From owner-recombination@net.bio.net Sun Apr 13 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET ("Graham Dellaire") Newsgroups: bionet.molbio.recombination Subject: POSTDOC in DNA REPLICATION (Dr. Carl Schildkraut) Date: 14 Apr 1997 16:18:45 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 48 Sender: daemon@net.bio.net Distribution: world Message-ID: <97Apr14.191929-0400_edt.585982-8564+4316@skywalker.microtec.net> NNTP-Posting-Host: net.bio.net To: biojobs@net.bio.net From: schildkr@aecom.yu.edu (Dr. Carl Schildkraut) Subject: POSTDOCTORAL FELLOW POSITION, DNA REPLICATION Date: 3 Apr 1997 16:37:10 GMT POSTDOCTORAL FELLOW POSITION AVAILABLE A position is available to study the molecular genetics of replication and the cell cycle in the mammalian genome. We use Epstein-Barr and human papilloma virus sequences as model systems both in vivo and in vitro to study site-specific initiation and termination of DNA replication (Cell 58:527, 1989; Mol. Cell. Biol. 11:6268, 1991; J. Virol. 67:1739, 1993; Mol. Cell. Biol. 15:2893, 1995; J. Biol. Chem. 271:33009, 1996). The replication of globin and immunoglobulin gene families (Mol. Cell. Biol. 8: 2149 and 4958, 1988; 9:3524, 1989; 10:4314 and 4324, 1990) and the role of replication in oncogene rearrangements and in development is being investigated. We are characterizing origins of replication that we have identified in human rDNA (Mol. Cell. Biol., 13:6600, 1993). Targeted integration mediated by homologous recombination will be used to modify chromosomal origins and to determine the sequences critical for origin function. Other projects include the role of the Locus Control Region (LCR) in the regulation of replication of globin and immunoglobulin gene loci. The spatial and temporal organization of DNA replication in mammalian nuclei is also being studied. Supported by NIH funding for at least three years. The Albert Einstein College of Medicine is located in a pleasant, very safe, residential area of New York. Send curriculum vitae by both Email and FAX or Air Mail and the names of three references (including telephone, FAX and Email numbers) to: Dr. Carl Schildkraut Department of Cell Biology (CH 416) Albert Einstein College of Medicine 1300 Morris Park Ave. New York, New York 10461 Phone (718) 430-2097 FAX (718) 430-8574 Email schildkr@aecom.yu.edu From owner-recombination@net.bio.net Sun Apr 13 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET (Graham Dellaire) Newsgroups: bionet.molbio.recombination Subject: Re:Ethics of Genetic Engineering Date: 14 Apr 1997 16:13:49 -0700 Organization: McGill Div. of Experimental Medicine Lines: 10 Sender: daemon@net.bio.net Distribution: world Message-ID: <3352B9E8.93@odyssee.net> Reply-To: dellaire@odyssee.net NNTP-Posting-Host: net.bio.net Nanda are you familiar with MEDLINE You can use it from your local library. Type in Keywords and it will lead you to articles on Gene Therapy and Genetics. I believe there is a Gene Therapy Journal as well and the first 5 issues or so are devoted to ethical issues of Gene Therapy. This is really dated already but is a good start. Graham From owner-recombination@net.bio.net Sun Apr 13 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET ("Graham Dellaire") Newsgroups: bionet.molbio.recombination Subject: THE SCIENCE GUIDE (Science News and Much more) Date: 14 Apr 1997 15:10:16 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 148 Sender: daemon@net.bio.net Distribution: world Message-ID: <97Apr14.181102-0400_edt.585891-8564+4211@skywalker.microtec.net> NNTP-Posting-Host: net.bio.net ---------- > From: Robert W. Georgantas III > To: GENSTRUCTURE Graham Dellaire > Subject: Help with a Posting > Date: Monday, April 14, 1997 1:28 PM > > To: Graham Dellaire > Moderator of the GENSTRUCTURE BioNet Discussion Group. > > I was hoping that you could help me, please read the letter below then do > with it as you wish. > > I am a student with the Department of Pharmacology and Molecular Sciences > at Johns Hopkins University, School of Medicine. I have started up a > small internet site called "The Science Guide" located at the URL > http://www.scienceguide.com. I started the site to address the lack of a > unifying source of information for scientists on the internet. As you > can see in the announcement below the Guide consists of a number of > sections designed to help scientists find information on the internet, > The news section is currently our most popular service receiving over 4K > visits per day, with a hundreds of subscribers to the Daily News Emailer. > > Since we do not charge for our service, and since we are not accepting > advertisers; we have only a small number of routes by which to spread the > word about the Guide (we have no advertising budget as well). One of > these routes is by posting to Usenet groups. We have done this on a > small basis by looking at a news group to assure that the users of the > group are appropriate for our service, and then posting the Announcement > enclosed below to the group. We Do Not Spam. Over the last month we > have posted to roughly forty news groups and have received a great > response in the form of emails telling us how useful our site is, and > will become as we add more content to it. We have not received a single > negative response, which we have interpreted to mean that our site is > useful enough to scientists that they do not mind our "off-subject" > posting. > > That brings me to the crux of the email, I was hoping that you could take > the time to visit the Science Guide, determine if it would be of use to > the subscribers of the group which you modify, and if so - post the > announcement text below to the group. This would be of great help to us > in getting the word out about the Guide. > > If you feel that this posting would be inappropriate, please accept my > apologies for having taken your time, and just disregard this letter. > > One thing that may be particularly of interest, is our plan to start > monitoring Congress for bills containing items concerning scientific > funding. We plan on doing this to take advantage of the power of the > internet to set up a pseudo lobbying group. As an example - during the > Congressional Debates over the NIH budget a few months ago we encouraged > our readers to email their congress-person asking for an increase in the > budget. At the time we had just started the guide and had only a small > number of readers, but now that we have literally thousands of users (and > our usership is growing at 40% per week) and we think that we could make > a significant difference in funding by informing our users of congresses' > actions and helping them to act in writing to the House, or Senate, or > President. > > Thank you > Robert Georgantas - The Science Guide > > PS. You can check to make sure that I am actually who I say that I am > buy fingering my student email account: rgeorgan@welchlink.welch.jhu.edu. > The Science Guide is hosted under the .com domain by Hway Technologies, > because Hopkins was not willing to host a site with our potential traffic. > > > ------------------Announcement Text------------------------ > > Announcing the SCIENCE GUIDE. > http://www.scienceguide.com > > A New Internet Directory and Information Service run by Scientists and > Physicians for Scientists and Physicians. After visiting the Guide, If > you have any suggestion for making the Guide better please let us know. > (webmaster@scienceguide.com) > > The Science Guide consists of a number of different sections designed to > help the scientist and physician find information on the internet and to > sponsor communication between those interested in science: > > > NEWS SECTION > > Every day the Science Guide compiles medical and research news from > national news sources around the net. Most of the news articles are > concerned with medicine, bioscience, and physics, but all other sciences > from agriculture to zoology are commonly included. News sources currently > listed include: CNN, EurekAlert, HMS Beagle, MSNBC Sci-Tech, Science > Magazine's ScienceNow, CBS Space News, USA Today, The Albuquerque > Journal, Scientific American Web Weekly, The Why Files, Discover > Magazine, Scientific American, Smithsonian Magazine, and the Technology > Review. The news pages also list links to news sources not compiled > within the News site. We are currently working on adding a number of > other sources to the site to make it even more useful. > > To make getting science news even easier, we send out a DAILY NEWS > EMAILER listing the articles which have been compiled on our site. > Anyone can subscribe to the Emailer by sending an email to > news@scienceguide.com with the message "Subscribe" > > > DIRECTORY OF USENET NEWS GROUPS and DISCUSSION LISTS > > The Directory of Usenet and Discussion Groups is compiled quarterly from > different sources around the net to provide the scientist and those > interested in science easy access to these invaluable sources of > discourse and information. We are currently working on finding the > proper subscription method for each of the discussion lists. This is > taking a bit longer that we thought so please pardon our dust. The > Usenet portions of this section are complete. > > > ON-LINE JOURNAL HYPERLINK SECTION > > The Journals Section contains links to peer reviewed scientific journals > on the Internet. Each listing clearly indicates whether the journal > provides only the table of contents, TOC with abstracts, or the full text > of the journal > > > EMPLOYMENT SECTION > > The Jobs and Positions Section contains hyperlinks to the best Scientific > Employment Databases and Classifieds on the net. > > > GRANTS and FUNDING SECTION > > The funding section contains links to the best funding and grant > databases on the Internet, making it very easy for scientists to quickly > find funding opportunities. The featured site of the section is "The > Community of Science," a Johns Hopkins service designed to help > scientists find and continue funding. From owner-recombination@net.bio.net Sun Apr 13 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET ("Graham Dellaire") Newsgroups: bionet.molbio.recombination Subject: New on EMJL for March and April '97 (JOBS IN BIOLOGY/BIOMEDICINE) Date: 14 Apr 1997 16:29:24 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 90 Sender: daemon@net.bio.net Distribution: world Message-ID: <97Apr14.192947-0400_edt.585994-8565+4252@skywalker.microtec.net> NNTP-Posting-Host: net.bio.net DO NOT REPLY TO THIS POST DIRECTLY BUT PLEASE VISIT THE EXPERIMENTAL MEDICINE JOB LISTING (EMJL) at: http://www.medcor.mcgill.ca/EXPMED/DOCS/jobs.html =================================================== New on EXPERIMENTAL MEDICINE JOB LISTING (EMJL) The following are some of new the postings we have received in March and April: Canada 1.Ph.D. Molecular mechanisms regulating the activity and substrate specificity of cholinephosphotransferase and lysophosphatidylcholine acyltransferase -in the laboratory of Dr. Christopher R. McMaster (Dalhousie Univeristy, Halifax, Nova Scotia) http://www.medcor.mcgill.ca/EXPMED/DOCS/jobs.html#ATL 2.Post-doctoral Position in therapeutic strategies for cancer treatment using protein toxins - in the Laboratory of Dr. Jean Gariepy at the University of Toronto (Toronto, Ontario) http://www.medcor.mcgill.ca/EXPMED/DOCS/jobs.html#ONT United States 3.Post-doc to study a novel family of murine homeobox genes that are involved in embryonic development of the mesoderm and nervous system - in the laboratory of Dr. Thomas Lufkin (Brookdale Center for Molecular Biology, New York, New York) 4. Two Post-doc positions (studies beta globin LCR and Tal1 protein) -in the laboratory of Dr. Emery Bresnick (University of Wisconsin-Madison) http://www.medcor.mcgill.ca/EXPMED/DOCS/jobs.html#US EUROPE: Germany 5.Ph.D. Student Position, Multidrug Resistance in Human Tumors - in the laboratory of Dr. Ulrike Stein at the Max-Delbrueck-Center for Molecular Medicine (Berlin, Germany) Available Immediately Neatherlands 6.Post-doc to study effects of nuclear/chromatin structure on transcription of the globin locus -in the laboratory of Dr. Peter Fraser (Erasmus University, Rotterdam) http://www.medcor.mcgill.ca/EXPMED/DOCS/jobs.html#EURO +++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please Visit the EMJL Web Page to apply, do not reply to this post directly. http://www.medcor.mcgill.ca/EXPMED/DOCS/jobs.html All e-mail received by Graham Dellaire at dellaire@odyssee.net will be deleted without comment. +++++++++++++++++++++++++++++++++++++++++++++++++++++++ ===================================== | Graham Dellaire | | Division of Experimental Medicine | Dept of Medicine, McGill University |(http://www.medcor.mcgill.ca/EXPMED/expmed.html) | | e-mail: dellaire@odyssee.net | Fax: (514) 896 4689 | Vox: (514) 281 6000 ext. 6936 | | Bionet: bionet.molbio.recombination | bionet.genome.gene-structure ===================================== | Snail Mail: | Institut du Cancer de Montreal | Centre de Recherch L.C. Simard | 1560 Sherbrooke St. East | Montreal, Quebec, CANADA | H2L 4M1 ===================================== From owner-recombination@net.bio.net Sun Apr 13 23:00:00 1997 Path: biosci!daresbury!not-for-mail From: "Nanda Somarajan" Newsgroups: bionet.molbio.recombination Subject: Ethics of Genetic Engineering Date: 14 Apr 1997 01:13:05 +0100 Lines: 28 Sender: lpddist@mserv1.dl.ac.uk Distribution: bionet Message-ID: <5irsqh$4e6@mserv1.dl.ac.uk> X-Originating-IP: [165.134.21.21] Original-To: molmodel@net.bio.net Hi. I have to write a 10 page paper in English and I have decided to do it on the Ethics of Genetic Engineering. Can anyone give me any sources that I can find information on this topic? I am first telling what genetic engineering is and then I tell the consequences of it-such as genetic discrimination due to having a gene for a certain disease and human cloning. I also talk about the human genome project and genetic recombination. I also want to talk about the possibility of someone genetically creating a deadly virus to kill people. Any sources of information on any of the topics I talked about above would be help-including how it works, the consequences, what organisms are used to transfer the genes-would be helpful. Sources such as journals, books, Internet...would be helpful. Can you please just e-mail me your reply please instead of just posting in on the newsgroup. Thank you very, very much. ********************************************************************** Nanda Somarajan somarank@slu.edu somarank@hotmail.com Ebola Information Headquarters: http://www.angelfire.com/ok/nanda ********************************************************************** --------------------------------------------------------- Get Your *Web-Based* Free Email at http://www.hotmail.com --------------------------------------------------------- From owner-recombination@net.bio.net Tue Apr 15 23:00:00 1997 Path: biosci!fcs280s.ncifcrf.gov!cpk-news-feed1.bbnplanet.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!news.maxwell.syr.edu!news.mathworks.com!uunet!in3.uu.net!140.142.64.3!news.u.washington.edu!pogo!evolution From: Mark Mozden <72012.1130@CompuServe.COM> Newsgroups: bionet.general,bionet.molbio.recombination,sci.bio.technology Subject: A writer's questions Date: 12 Apr 1997 16:03:27 GMT Organization: CompuServe, Inc. (1-800-689-0736) Lines: 14 Distribution: inet Message-ID: <5iobof$csk$1@mhade.production.compuserve.com> NNTP-Posting-Host: pogo.cqs.washington.edu Status: RO Originator: evolution@pogo Xref: biosci bionet.general:26454 bionet.molbio.recombination:407 sci.bio.technology:7745 Hi, I'm a techno-y writer with the following questions for any kind hearted soul-in-the-know in this busy medium: 1) What is the approximate DNA similarity between a human and a rat? All I need is a rough estimate... 2) Is there a new/better truth serum beyond Thiopental? 3) Can you name a good coffee shop in Cambridge where scientist types are likely to hang out and get wired? Post note, or preferably email me direct at: 72012.1130@Compuserve.Com I thank you for any questions you can answer, and I appreciate your time. -Mark Mozden From owner-recombination@net.bio.net Tue Apr 15 23:00:00 1997 Path: biosci!agate!howland.erols.net!rill.news.pipex.net!pipex!oleane!jussieu.fr!rallye.ijm.jussieu.fr!user From: matic@saphir.ijm.jussieu.fr. (ivan matic) Newsgroups: bionet.molbio.recombination Subject: natural transformation of E. coli Date: Wed, 16 Apr 1997 14:00:58 +0100 Organization: ijm Lines: 6 Message-ID: NNTP-Posting-Host: rallye.ijm.jussieu.fr Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit E. coli has been considered as naturally non-transformable microorganism. However, recently (Applied and Environ. Microbiol. 1996 vol. 62 page 3673-78) the transformation of E. coli in freshwahter has been reported. Does anybody know for some other studies concerning natural transformability of E. coli or S. typhimurium. I am particulary interested of the reports on transformation in vivo. Thank you in advance!!! From owner-recombination@net.bio.net Tue Apr 15 23:00:00 1997 Path: biosci!daresbury!uninett.no!hermod.uio.no!nntp.uio.no!newsfeeds.sol.net!feed1.news.erols.com!news.maxwell.syr.edu!EU.net!newsfeed.Austria.EU.net!newscore.univie.ac.at!news-ge.switch.ch!feed2.belnet.be!news.belnet.be!alpha.luc.ac.be!pstn10.luc.ac.be!user From: ghermans@luc.ac.be (Guy Hermans) Newsgroups: bionet.molbio.recombination Subject: pTRACER stability without T antigen?? Date: Wed, 16 Apr 1997 18:18:21 +0100 Organization: Dr. L. Willems-Instituut Lines: 29 Message-ID: Reply-To: hellings@luc.ac.be NNTP-Posting-Host: pstn10.luc.ac.be I'm considering of using the new pTRACER vectors of Invitrogen. It are vectors with an SV40 ori and as tracer GFP. I'm planning of using them to express a gene in lymphocytes. My questions: 1. Is it possible to use this vector in transfections of T lymphocytes? They don't have the large T antigen, and I wondered if the T antigen is a necessary factor? It doesn't say anything in the folder I got. What will theoretically happen with the SV40 plasmid vector? Will it replicate together with the cells? It is possible to select for an antibiotic. 2. Does anyone have experience with this at all? Thanks for the help niels hellings -- Niels Hellings, PhD student Ms research Unit Immunology research group Dr. L. Willems-Institute Dept. of Physiology, LUC University Campus University Campus B-3590 Diepenbeek B-3590 Diepenbeek Belgium Belgium Voice ++32(0)11/26.92.07 Fax ++32(0)11/26.92.09 -- Niels From owner-recombination@net.bio.net Tue Apr 15 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET (Graham Dellaire) Newsgroups: bionet.molbio.recombination Subject: RE:pTRACER stability without T antigen?? Date: 16 Apr 1997 16:56:53 -0700 Organization: McGill Div. of Experimental Medicine Lines: 31 Sender: daemon@net.bio.net Distribution: world Message-ID: <335566A7.3256@odyssee.net> Reply-To: dellaire@odyssee.net NNTP-Posting-Host: net.bio.net Hello Niels, Without the T-antigen these cells won't replicate efficiently. What will happen is that the vector will be maintained extrachromosomally for perhaps 48 to 72 hours and then will be lost as each generation of cells dilutes out the original amount of plasmid DNA (i.e. each time a cell divides each daughter gets half the total molecules -theoretically-). This is fine for quick transient studies of gene expression or for coimmunoprecipitation etc. YOu can have stable transfection but this involves integration of the vector illegitimately after a break in the plasmid. This may occur at a frequency of anywhere between 10-3 to 10-4 per cell transfected (depending on the recombinogenicity of your cell line... murine LTA fibroblasts for instance are very recombinogenic). Any stable clones will be due to integrated plasmid and not extrachromosomal plasmid. IF you are transfecting lymphocytes you should probably use lipofectin or some other lipid or cationic carrier. Electroporation also works but you will kill many cells, so if your cells are hard to come by use lipofectin. Regards, Graham Dellaire McGill Div. of Exp. Medicine dellaire@odyssee.net From owner-recombination@net.bio.net Thu Apr 17 23:00:00 1997 Path: biosci!internet!biosci!not-for-mail From: biohelp (BIOSCI Administrator) Newsgroups: bionet.molbio.recombination Subject: BIOSCI/bionet miniFAQ & Fundraiser Date: 18 Apr 1997 02:00:24 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 239 Sender: daemon@net.bio.net Distribution: world Message-ID: <199704180900.CAA16455@net.bio.net> NNTP-Posting-Host: net.bio.net (LAST REVISION: 30-JUL-95) This BIOSCI "miniFAQ" is designed to answer the questions that come up the *most frequently*. The main BIOSCI FAQ (Frequently Asked Questions) is accessible on the World Wide Web at URL http://www.bio.net/. If you can not find an answer to your question in this or other documentation, the BIOSCI technical support staff answers e-mail queries sent to biosci-help@net.bio.net We can only answer questions about the use of the newsgroups and mailing lists. We unfortunately do not have the staff to do Internet information searches or answer scientific questions. Please post those to the appropriate BIOSCI/bionet newsgroups. Contents: -------- 0) BIOSCI NEEDS YOUR SUPPORT!! 1) Using the WWW to access the BIOSCI/bionet newsgroups. 2) What to do about "spams," i.e., junk mail, ads, etc. 3) Examples of subscribing and unsubscribing to the mailing lists. 4) The BIOSCI user address and research interest directory. 0) BIOSCI NEEDS YOUR SUPPORT!! ------------------------------ BIOSCI's government funding has been expended, and we are now operating solely from advertising revenue that we have raised from our Web site at http://www.bio.net/. We need just a few minutes of your time to help us serve you. You can do two important things which will take very little time for you individually and will immensely help us continue to help you. First, please use our WWW system at http://www.bio.net/ to access the archives. You can post or reply to messages via your Web browser as described in item #1 below. Your usage helps attract sponsors. If you contact any of our sponsors, please be sure to thank them for supporting BIOSCI. It is critical for them to get this feedback if they are to continue their sponsorship for the long term. Second, if you work for a company or organization that provides products or services of interest to the biology community, please pass this message on to your marketing or marketing communications department or other appropriate group. Please ask them to help support BIOSCI by sponsoring our Web site and explain the uses and benefits of the system to the biology community. If they are interested, they can then contact us for further information at our tech support address, biosci-help@net.bio.net. 1) Using the WWW to access the BIOSCI/bionet newsgroups. -------------------------------------------------------- As of 10 December 1995, all BIOSCI/bionet full newsgroups are accessible through the World Wide Web (WWW) at URL http://www.bio.net. One can read and reply publicly or privately to both recent postings and archived messages through one's Web browser if it is configured properly to send e-mail. Each newsgroup is equipped with its own WAIS index. The main BIOSCI home page also has access to the BIO-JOURNALS Table of Contents database WAIS index and the BIOSCI user address database described in another item further below. 2) What to do about "spams," i.e., junk mail, ads, etc. ------------------------------------------------------- BIOSCI is a set of parallel USENET newsgroups (the "bionet" groups), mailing lists, and a hypermail archive at URL http://www.bio.net/. The same postings are distributed on all media (except for a small number of mailing-list-only groups at net.bio.net). Unfortunately it is becoming a despicable practice on the Internet (by a few people out to make a fast buck) to do automated mass postings to thousands of newsgroups and mailing lists. These attempts to grab free advertising are refered to as "spams" in the usual, somewhat boneheaded, net terminology. USENET is more susceptible to this practice, and many spams originate on the USENET groups and then are passed on to the mailing lists. However, spammers also get lists of mailing addresses and hit these too, so neither medium is immune. What should you do personally if you get junk mail? --------------------------------------------------- Just delete it and move on without reading it further. Filing a protest is becoming increasingly useless because spammers are often disguising the addresses where the messages are sent from. Unless you really understand Internet mail systems, your attempt at protest by sending replies to the message will often end up being sent to the address of an innocent person that the spammer is victimizing. What can BIOSCI/bionet do to protect its newsgroups? ---------------------------------------------------- The only solution currently available is to moderate the newsgroup. If this newsgroup is already moderated, then you are in good shape. Moderation protects the USENET distribution from about 95% of the spams that are being sent to date and protects the mailing lists completely. Moderation means, however, that someone has to take the time to review each message before it goes out. We have set up software here that simply allows the moderator to forward to an address at net.bio.net messages that (s)he wishes to have distributed. This takes no more time than that needed to read the message and pass it on, say about 1 min. per message. Most newsgroups currently have a discussion leader who is responsible for their newsgroup. The discussions leaders and their e-mail addresses are listed in the BIOSCI Information Sheet which is available on the Web at http://www.bio.net/. If a newsgroup is being hit with too many junk postings, please contact the discussion leader for that group and see if there is interest in moderating the group. Please do not assume that by simply posting a complaint to the newsgroup itself, anyone on the BIOSCI staff will act on your complaint. With close to 100 newsgroups to run, the BIOSCI staff has to rely on the discussion leaders of each newsgroup to report problems directly to us at biosci-help@net.bio.net. We will moderate any of our newsgroups if the discussion leader tells us that the readership of the group wishes to do so and if a moderator is willing to do the work. For most BIOSCI/bionet groups, this entails only a few minutes of work each day. Moderating a newsgroup will resolve probably 95% of the junk postings on the USENET distribution. Unfortunately there are easy ways for determined spammers to override the moderation mechanism on USENET, but we can protect our e-mail subscribers from unwanted postings if the newsgroup is moderated. You can also access our newsgroups over the WWW at URL http://www.bio.net. While this Web interface will not stop spammers from trying to post to the groups, this will give you yet another way, besides using USENET news, to keep the junk out of your personal mail files. For those of you with local USENET news systems, the Web interface will also give you faster access to new newsgroups and recent postings. 3) Examples of subscribing and unsubscribing to the mailing lists. ------------------------------------------------------------------ PLEASE NOTE: The BIOSCI management does NOT act on subscription/unsubscription requests that are posted improperly to the newsgroups and mailing lists. People who do this only bother everyone on the lists to no avail. Please be sure to follow the proper procedures below. Gory details are in the BIOSCI Information sheets on the Web at http://www.bio.net. Below we give an example utilizing the METHODS-AND-REAGENTS list at both of our two BIOSCI sites: Users in the Americas and Pacific Rim countries who use the BIOSCI ------------------------------------------------------------------ node at computer net.bio.net: ---------------------------- A) Determine the "listname" which is the <=8 character mail address ^^^^^^^^^^^^^ for the group. These can be found in the BIOSCI Info. Sheet. For the METHODS-AND-REAGENTS group the mailing address is methods@net.bio.net. The listname is the portion of the address to the left of the @ sign, i.e., "methods". The listname is used with the "subscribe" and "unsubscribe" commands illustrated below. B) Mail all commands in the body of a mail message addressed to biosci-server@net.bio.net. Do NOT send commands to the newsgroup posting addresses! Leave the Subject: line blank, any text on it will be ignored. C) In the body of your message put one or more of the following commands with an "end" command on the last line, e.g., subscribe methods unsubscribe methods end Do NOT put your e-mail address or other text on these lines. The server only allows you to cancel your subscription if the address on your mail header matches the address on our mailing list. Please ask for help at biosci-help@net.bio.net if your address has changed, e.g., if you know you are on the list but the server tells you that you are not a member. Users in Europe, Africa, and Central Asia who use the BIOSCI node at -------------------------------------------------------------------- computer daresbury.ac.uk (also known as dl.ac.uk): ------------------------------------------------- To subscribe and unsubscribe to/from the BIOSCI lists, you need to specify the full USENET newsgroup name with "bionet-news." prepended. The USENET newsgroup names are listed in the BIOSCI Information sheet on the Web at http://www.bio.net/. For the METHODS-AND-REAGENTS list the USENET newsgroup name is bionet.molbio.methds-reagnts, thus the appropriate commands are sub bionet-news.bionet.molbio.methds-reagnts unsub bionet-news.bionet.molbio.methds-reagnts These commands are included in a message addressed to mxt@dl.ac.uk, NOT to the newsgroup mailing addresses. As usual, include the text in the body of the message as text on the Subject: line is ignored. To unsubscribe from all the lists at the UK node, use unsub bionet-news Please note that if the address in the list is different than the one in your mail message header, you will not be able to unsubscribe by this method. If you have problems, please mail biosci@daresbury.ac.uk. 4) The BIOSCI user address and research interest directory. ----------------------------------------------------------- Please take this opportunity to add your name, address, and research interest information to the BIOSCI User Address Database if you have not already done so. You can fill out the address form directly through our Web page at URL http://www.bio.net/adrform.html. The address database is reindexed nightly for WWW access (the URL is http://www.bio.net/). If you are not directly on the Internet but can reach it by e-mail, please use our waismail server to access the user directory. waismail use is described above. You can also request a user address form by e-mail from biosci-help@net.bio.net. Please check your database entry from time-to-time to see if your address information is still up-to-date. Because of our limited personnel resources, we ask that you resubmit a *complete* form to revise your entry; we only replace complete entries and do not have resources to edit old forms. Sincerely, Dave Kristofferson BIOSCI/bionet Manager biosci-help@net.bio.net From owner-recombination@net.bio.net Mon Apr 21 23:00:00 1997 Path: biosci!ims.unich.it!"masulli" From: "masulli"@ims.unich.it (masulli michele) Newsgroups: bionet.molbio.recombination Subject: suicide vectors Date: 22 Apr 1997 02:07:12 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 2 Sender: daemon@net.bio.net Distribution: world Message-ID: <9704220906.AA24658@phobos.unich.it> NNTP-Posting-Host: net.bio.net I looking for suicide vector for Proteus mirabilis. any information are welcome. nerino allocati From owner-recombination@net.bio.net Mon Apr 21 23:00:00 1997 Newsgroups: bionet.molbio.recombination Path: biosci!fcs280s.ncifcrf.gov!cpk-news-feed1.bbnplanet.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!news.maxwell.syr.edu!uknet!usenet1.news.uk.psi.net!uknet!uknet!bcc.ac.uk!news From: Paul Wells Subject: PRACTICAL COURSE IN GENETIC ENGINEERING Message-ID: <1997Apr22.133528.86267@ucl.ac.uk> Date: Tue, 22 Apr 1997 13:35:28 GMT Organization: University College London Lines: 35 A one week practical course designed to teach the basic techniques in genetic engineering will be held from 16th-20th June 1997 at the Dept. of Biochemistry and Molecular Biology University College London. A "hands on" approach will enable scientists from higher education and industry, clinicians and research workers who have had no practical experience of recombinant DNA technology to set up such techniques in their own laboratories. Techniques to be covered will include, Southern hybridisation DNA sequencing, PCR, and analysis of cloned DNA using enzyme restriction mapping. Supplemented with some lectures. Course fee 900 pounds sterling (750 for full time postgraduate students) exclusive of accommodation. Bed and breakfast accommodation for the period of the course can be provided in a local hall of residence for 102 pounds sterling from Sunday 15th June until Saturday 21st June. For further information visit our web site "http://www.biochem.ucl.ac.uk/~wells/pige97.htm Write for application forms to: Dr. John Ward Department of Biochemistry & Molecular Biology University College London Gower Street London WC1E 6BT Fax: 0171 380 7193 Or e-mail either:- j.ward@biochem.ucl.ac.uk p.wells@ucl.ac.uk From owner-recombination@net.bio.net Wed Apr 23 23:00:00 1997 Path: biosci!OSPREY.UNF.EDU!jander From: jander@OSPREY.UNF.EDU ("John E. Anderson") Newsgroups: bionet.molbio.recombination Subject: location of crossovers with respect to coding sequences Date: 23 Apr 1997 22:40:18 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 26 Sender: daemon@net.bio.net Distribution: world Message-ID: <335EF246.442F@osprey.unf.edu> NNTP-Posting-Host: net.bio.net Hi I am teaching a course in general biology, and in the section on evolution, I'm puzzled by the statement in at least two textbooks that sexual recombination, i.e. meiotic crossover, can't generate new alleles. If one of the two alleles of a gene carries a mutation near the 5' end of the coding sequence, and the other carries a mutation near the 3' end, then crossover between the two mutations would generate two new alleles, one with both mutations and one with neither: 5'---*----------3' 5'---*------*---3' X ---> 5'----------*---3' 5'--------------3' Is there something wrong with my thinking here? Please respond by email as well as to the list, as I don't read this list regularly. Thanks a lot for your help. John Anderson -- John E. Anderson jander@unf.edu From owner-recombination@net.bio.net Thu Apr 24 23:00:00 1997 Path: biosci!daresbury!uninett.no!news-feed.inet.tele.dk!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!news-peer.sprintlink.net!news.sprintlink.net!sprint!uunet!in1.uu.net!136.142.185.26!newsfeed.pitt.edu!newsflash.concordia.ca!news.mcgill.ca!news From: Terry Chow Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: Fri, 25 Apr 1997 12:56:43 -0400 Organization: McGill University Computing Centre Lines: 40 Message-ID: <3360E24B.3106@musica.mcgill.ca> References: <335EF246.442F@osprey.unf.edu> NNTP-Posting-Host: 198.168.147.137 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0Gold (Win95; I) To: "John E. Anderson" John E. Anderson wrote: > > Hi > > I am teaching a course in general biology, and in the section on > evolution, I'm puzzled by the statement in at least two textbooks that > sexual recombination, i.e. meiotic crossover, can't generate new > alleles. If one of the two alleles of a gene carries a mutation near > the 5' end of the coding sequence, and the other carries a mutation near > the 3' end, then crossover between the two mutations would generate two > new alleles, one with both mutations and one with neither: > > 5'---*----------3' 5'---*------*---3' > X ---> > 5'----------*---3' 5'--------------3' > > Is there something wrong with my thinking here? > > Please respond by email as well as to the list, as I don't read this > list regularly. > > Thanks a lot for your help. > > John Anderson > -- > John E. Anderson > jander@unf.edu Dear John, You are partly right. The event that you described is only rearrange the existing information. The alleles of 3' mutation and 5' mutation are only rearranged. There is no generation of "new allele" as if mutation event has occurred. What the textbook mean is that recombination in general is not mutagenic. It does not generate "new thing" but only rearrange existing one. I hope this explanation will help. Terry Chow From owner-recombination@net.bio.net Sat Apr 26 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET (Graham Dellaire) Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: 27 Apr 1997 09:22:12 -0700 Organization: McGill Div. of Experimental Medicine Lines: 32 Sender: daemon@net.bio.net Distribution: world Message-ID: <33637C71.3898@odyssee.net> Reply-To: dellaire@odyssee.net NNTP-Posting-Host: net.bio.net Hello John and Terry, YOu wrote: "I'm puzzled by the statement in at least two textbooks that sexual recombination, i.e. meiotic crossover, can't generate new alleles." and Terry responded: "What the textbook mean is that recombination in general is not mutagenic. It does not generate "new thing" but only rearrange existing one." I agree with what Terry said but I would add a qualifier: "gene conversion and equal X-over", found during mieotic recombination, are usually not mutagenic. So the text book is probably referring to normal equal X-over, and gene conversion occuring during mieosis between two reciprocal alleles. You are very right to assume recombination can be mutagenic. The repair of DNA damage by recombination in the germline fixes mutations and is one possible mechanism, of many, of evolution. Illegitimate recombination can very easily disrupt an allele or create a hybrid one(ex. translocation event leading to the Philadelphia chromosome in chronic mylogenous leukemia (CML) which creates a new oncogene by combining bcr and the tyrosine kinase abl). Graham Dellaire dellaire@odyssee.net From owner-recombination@net.bio.net Sun Apr 27 23:00:00 1997 Path: biosci!fcs280s.ncifcrf.gov!cpk-news-feed1.bbnplanet.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!rill.news.pipex.net!pipex!uunet!in2.uu.net!132.205.106.4!newsflash.concordia.ca!news.mcgill.ca!news From: Terry Chow Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: Mon, 28 Apr 1997 10:33:16 -0400 Organization: McGill University Computing Centre Lines: 50 Message-ID: <3364B52B.3922@musica.mcgill.ca> References: <33637C71.3898@odyssee.net> NNTP-Posting-Host: 198.168.147.137 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0Gold (Win95; I) Graham Dellaire wrote: > > Hello John and Terry, > > YOu wrote: > "I'm puzzled by the statement in at least two textbooks that > sexual recombination, i.e. meiotic crossover, can't generate new > alleles." > > and Terry responded: > > "What the textbook mean is that recombination in general is not > mutagenic. It does not generate "new thing" but only rearrange existing > one." > > I agree with what Terry said but I would add a qualifier: "gene > conversion and equal X-over", found during mieotic recombination, are > usually not mutagenic. So the text book is probably referring to normal > equal X-over, and gene conversion occuring during mieosis between two > reciprocal alleles. > > You are very right to assume recombination can be mutagenic. The > repair of DNA damage by recombination in the germline fixes mutations > and is one possible mechanism, of many, of evolution. > > Illegitimate recombination can very easily disrupt an allele or create a > hybrid one(ex. translocation event leading to the Philadelphia > chromosome in chronic mylogenous leukemia (CML) which creates a new > oncogene by combining bcr and the tyrosine kinase abl). > > Graham Dellaire > > dellaire@odyssee.net Hello Graham, If you get into illegitimate recombination, then there will be almost infinite potential of generating different alleles. But, however, almost all the mieotic recombination are normal homologous type of events. If I use the example that John posted, then we are dealing with three alleles. The normal, wild-type alleles, the 3' mutated alleles, and the 5' mutated alleles. If we consider only the each of the alleles in the gene, there is no generation of new allele but only rearrange of the existing one; although in one case, the 3' mutated allele and the 5' mutated allele is in the same chromosome. Mutations generate by recombination events (including illegitimate recombination) are rare. Terry Chow mdty@musica.mcgill.ca From owner-recombination@net.bio.net Sun Apr 27 23:00:00 1997 Path: biosci!OSPREY.UNF.EDU!jander From: jander@OSPREY.UNF.EDU ("John E. Anderson") Newsgroups: bionet.molbio.recombination Subject: location of crossovers with respect to coding sequences Date: 28 Apr 1997 09:13:49 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 45 Sender: daemon@net.bio.net Distribution: world Message-ID: <3364CB14.6E38@osprey.unf.edu> NNTP-Posting-Host: net.bio.net This is a summary of responses and followup to the query I made to the list last week, which is reproduced here: > I am teaching a course in general biology, and in the section on > evolution, I'm puzzled by the statement in at least two textbooks that > sexual recombination, i.e. meiotic crossover, can't generate new > alleles. If one of the two alleles of a gene carries a mutation near > the 5' end of the coding sequence, and the other carries a mutation near > the 3' end, then crossover between the two mutations would generate two > new alleles, one with both mutations and one with neither: > > 5'---*----------3' 5'---*------*---3' > X ---> > 5'----------*---3' 5'--------------3' > > Is there something wrong with my thinking here? Of the four individuals who responded to me by email (whom I thank for their responses), two said that I am right, that recombination does occur within coding sequences and can produce new alleles. The other two said that I am partly right, that recombination such as I've indicated above would generate new alleles, but that these are not strictly speaking *new* because they just make a new combination of two already-existing mutations. I know what this argument is getting at, but I think that the two new alleles produced by the recombination I pictured above might very well produce products with very different properties than the original alleles. In that case, the two new alleles would be *functionally different* from the original two, and because of that, could contribute to the evolution of the population. Let me refine the original query a bit, though. What I intended to ask (which didn't come out in the post) was whether there is an observed tendency for crossovers to occur outside coding sequences, over and above what you might expect from the relative amount of coding versus non-coding DNA. For instance, is there a particular DNA sequence, perhaps in promoter regions, where recombination preferentially occurs? Again, please respond by email, and thanks for your help. John Anderson -- John E. Anderson jander@unf.edu From owner-recombination@net.bio.net Sun Apr 27 23:00:00 1997 Path: biosci!OSPREY.UNF.EDU!jander From: jander@OSPREY.UNF.EDU ("John E. Anderson") Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: 28 Apr 1997 16:34:04 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 82 Sender: daemon@net.bio.net Distribution: world Message-ID: <336532D5.2C7D@osprey.unf.edu> References: <3364B52B.3922@musica.mcgill.ca> NNTP-Posting-Host: net.bio.net Hi folks I've subscribed to the email list so I can follow this thread. Terry Chow wrote: > > Graham Dellaire wrote: > > > > Hello John and Terry, > > > > YOu wrote: > > "I'm puzzled by the statement in at least two textbooks that > > sexual recombination, i.e. meiotic crossover, can't generate new > > alleles." > > > > and Terry responded: > > > > "What the textbook mean is that recombination in general is not > > mutagenic. It does not generate "new thing" but only rearrange existing > > one." > > > > I agree with what Terry said but I would add a qualifier: "gene > > conversion and equal X-over", found during mieotic recombination, are > > usually not mutagenic. So the text book is probably referring to normal > > equal X-over, and gene conversion occuring during mieosis between two > > reciprocal alleles. > > > > You are very right to assume recombination can be mutagenic. The > > repair of DNA damage by recombination in the germline fixes mutations > > and is one possible mechanism, of many, of evolution. > > > > Illegitimate recombination can very easily disrupt an allele or create a > > hybrid one(ex. translocation event leading to the Philadelphia > > chromosome in chronic mylogenous leukemia (CML) which creates a new > > oncogene by combining bcr and the tyrosine kinase abl). > > > > Graham Dellaire > > > > dellaire@odyssee.net > > Hello Graham, > > If you get into illegitimate recombination, then there will be almost > infinite potential of generating different alleles. But, however, > almost all the mieotic recombination are normal homologous type of > events. If I use the example that John posted, then we are dealing with > three alleles. The normal, wild-type alleles, the 3' mutated alleles, > and the 5' mutated alleles. If we consider only the each of the alleles > in the gene, there is no generation of new allele but only rearrange of > the existing one; although in one case, the 3' mutated allele and the 5' > mutated allele is in the same chromosome. Mutations generate by > recombination events (including illegitimate recombination) are rare. > > Terry Chow > mdty@musica.mcgill.ca It looks like Terry considers the "allele" to be the base-pair change... sorry, if I'm wrong. I thought the allele was the entire gene, in which case the 3'/5' mutant in my example would be a new allele by virtue of having both mutations in the same gene. (It occurs to me as I'm writing this that maybe I wasn't clear that both mutations are supposed to be in the same gene...) In any case, I think that in the context of evolution, a "different allele" is a gene that specifies a gene product with a different function, which would affect a trait in such a way as to affect the fitness of the organism. The 3'/5' mutated gene product in my example could easily have a very different function than either of the parent gene products. Both of the parent alleles could be nonfunctional, for example, but the amino acid changes might compensate for each other in the 3'/5' mutant, so that the 3'/5' mutant protein structure would be functional. Or both of the single mutants might have partial function, and the double mutant be completely inactive. Or any of a number of other possibilities. So while the base pair changes in the 3'/5' mutant might not be novel, the mutant gene in which they both occur might have a product with a novel function, which would, at least by my functional definition, be a new allele in the population's gene pool. John -- John E. Anderson jander@unf.edu From owner-recombination@net.bio.net Mon Apr 28 23:00:00 1997 Path: biosci!GPU.SRV.UALBERTA.CA!hastings From: hastings@GPU.SRV.UALBERTA.CA (P Hastings) Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: 29 Apr 1997 07:39:58 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 106 Sender: daemon@net.bio.net Distribution: world Message-ID: References: <336532D5.2C7D@osprey.unf.edu> NNTP-Posting-Host: net.bio.net On 28 Apr 1997, John E. Anderson wrote: > Hi folks > > I've subscribed to the email list so I can follow this thread. > > Terry Chow wrote: > > > > Graham Dellaire wrote: > > > > > > Hello John and Terry, > > > > > > YOu wrote: > > > "I'm puzzled by the statement in at least two textbooks that > > > sexual recombination, i.e. meiotic crossover, can't generate new > > > alleles." > > > > > > and Terry responded: > > > > > > "What the textbook mean is that recombination in general is not > > > mutagenic. It does not generate "new thing" but only rearrange existing > > > one." > > > > > > I agree with what Terry said but I would add a qualifier: "gene > > > conversion and equal X-over", found during mieotic recombination, are > > > usually not mutagenic. So the text book is probably referring to normal > > > equal X-over, and gene conversion occuring during mieosis between two > > > reciprocal alleles. > > > > > > You are very right to assume recombination can be mutagenic. The > > > repair of DNA damage by recombination in the germline fixes mutations > > > and is one possible mechanism, of many, of evolution. > > > > > > Illegitimate recombination can very easily disrupt an allele or create a > > > hybrid one(ex. translocation event leading to the Philadelphia > > > chromosome in chronic mylogenous leukemia (CML) which creates a new > > > oncogene by combining bcr and the tyrosine kinase abl). > > > > > > Graham Dellaire > > > > > > dellaire@odyssee.net > > > > Hello Graham, > > > > If you get into illegitimate recombination, then there will be almost > > infinite potential of generating different alleles. But, however, > > almost all the mieotic recombination are normal homologous type of > > events. If I use the example that John posted, then we are dealing with > > three alleles. The normal, wild-type alleles, the 3' mutated alleles, > > and the 5' mutated alleles. If we consider only the each of the alleles > > in the gene, there is no generation of new allele but only rearrange of > > the existing one; although in one case, the 3' mutated allele and the 5' > > mutated allele is in the same chromosome. Mutations generate by > > recombination events (including illegitimate recombination) are rare. > > > > Terry Chow > > mdty@musica.mcgill.ca > > It looks like Terry considers the "allele" to be the base-pair change... > sorry, if I'm wrong. I thought the allele was the entire gene, in which > case the 3'/5' mutant in my example would be a new allele by virtue of > having both mutations in the same gene. (It occurs to me as I'm writing > this that maybe I wasn't clear that both mutations are supposed to be in > the same gene...) In any case, I think that in the context of evolution, > a "different allele" is a gene that specifies a gene product with a > different function, which would affect a trait in such a way as to > affect the fitness of the organism. The 3'/5' mutated gene product in > my example could easily have a very different function than either of > the parent gene products. Both of the parent alleles could be > nonfunctional, for example, but the amino acid changes might compensate > for each other in the 3'/5' mutant, so that the 3'/5' mutant protein > structure would be functional. Or both of the single mutants might have > partial function, and the double mutant be completely inactive. Or any > of a number of other possibilities. So while the base pair changes in > the 3'/5' mutant might not be novel, the mutant gene in which they both > occur might have a product with a novel function, which would, at least > by my functional definition, be a new allele in the population's gene > pool. > > John > -- > John E. Anderson > jander@unf.edu > > > The original concept of an allelomorph included the idea that alleles could not be separated by recombination, since the gene was the unit of recombination. When it became apparent that mutations of the same function in more or less the same place could recombine, they were known for a time as Pseudoalleles. This was dropped as it become apparent that different mutions of the same gene are hardly ever in the same place. This has left us with the problem you point out that a recombination person means a varient base-pair or so when she says allele, and we have no word for varient conditions of a gene. Of course you are right that a novel gene product can be generated by recombinations of alleles. This concept is in the population biology literature. It is improbable that recombination between alleles occurs by crossing-over. A crossover occupies a length in which conversion occurs. Usually, one end of the length is outside the gene where the event is initiated. recombination is turning out to be much more mutagenic than we had supposed, but I shall get back to this another time if anyone is interested. Phil. From owner-recombination@net.bio.net Mon Apr 28 23:00:00 1997 Path: biosci!bcm.tmc.edu!cs.utexas.edu!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!worldnet.att.net!dciteleport.com!usenet.logical.net!news.dal.ca!newsflash.concordia.ca!news.mcgill.ca!news From: Terry Chow Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: Tue, 29 Apr 1997 13:02:21 -0400 Organization: McGill University Computing Centre Lines: 95 Message-ID: <3366299D.7E8C@musica.mcgill.ca> References: <3364B52B.3922@musica.mcgill.ca> <336532D5.2C7D@osprey.unf.edu> NNTP-Posting-Host: 198.168.147.137 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0Gold (Win95; I) To: "John E. Anderson" John E. Anderson wrote: > > Hi folks > > I've subscribed to the email list so I can follow this thread. > > Terry Chow wrote: > > > > Graham Dellaire wrote: > > > > > > Hello John and Terry, > > > > > > YOu wrote: > > > "I'm puzzled by the statement in at least two textbooks that > > > sexual recombination, i.e. meiotic crossover, can't generate new > > > alleles." > > > > > > and Terry responded: > > > > > > "What the textbook mean is that recombination in general is not > > > mutagenic. It does not generate "new thing" but only rearrange existing > > > one." > > > > > > I agree with what Terry said but I would add a qualifier: "gene > > > conversion and equal X-over", found during mieotic recombination, are > > > usually not mutagenic. So the text book is probably referring to normal > > > equal X-over, and gene conversion occuring during mieosis between two > > > reciprocal alleles. > > > > > > You are very right to assume recombination can be mutagenic. The > > > repair of DNA damage by recombination in the germline fixes mutations > > > and is one possible mechanism, of many, of evolution. > > > > > > Illegitimate recombination can very easily disrupt an allele or create a > > > hybrid one(ex. translocation event leading to the Philadelphia > > > chromosome in chronic mylogenous leukemia (CML) which creates a new > > > oncogene by combining bcr and the tyrosine kinase abl). > > > > > > Graham Dellaire > > > > > > dellaire@odyssee.net > > > > Hello Graham, > > > > If you get into illegitimate recombination, then there will be almost > > infinite potential of generating different alleles. But, however, > > almost all the mieotic recombination are normal homologous type of > > events. If I use the example that John posted, then we are dealing with > > three alleles. The normal, wild-type alleles, the 3' mutated alleles, > > and the 5' mutated alleles. If we consider only the each of the alleles > > in the gene, there is no generation of new allele but only rearrange of > > the existing one; although in one case, the 3' mutated allele and the 5' > > mutated allele is in the same chromosome. Mutations generate by > > recombination events (including illegitimate recombination) are rare. > > > > Terry Chow > > mdty@musica.mcgill.ca > > It looks like Terry considers the "allele" to be the base-pair change... > sorry, if I'm wrong. I thought the allele was the entire gene, in which > case the 3'/5' mutant in my example would be a new allele by virtue of > having both mutations in the same gene. (It occurs to me as I'm writing > this that maybe I wasn't clear that both mutations are supposed to be in > the same gene...) In any case, I think that in the context of evolution, > a "different allele" is a gene that specifies a gene product with a > different function, which would affect a trait in such a way as to > affect the fitness of the organism. The 3'/5' mutated gene product in > my example could easily have a very different function than either of > the parent gene products. Both of the parent alleles could be > nonfunctional, for example, but the amino acid changes might compensate > for each other in the 3'/5' mutant, so that the 3'/5' mutant protein > structure would be functional. Or both of the single mutants might have > partial function, and the double mutant be completely inactive. Or any > of a number of other possibilities. So while the base pair changes in > the 3'/5' mutant might not be novel, the mutant gene in which they both > occur might have a product with a novel function, which would, at least > by my functional definition, be a new allele in the population's gene > pool. > > John > -- > John E. Anderson > jander@unf.edu Hi John, You are right. By the definition of the classical genetic, it is different alleles of the same gene. I just want to point out that, in a way, the example you cited is in theory of four alleles. 3', 5', 3'-5', and wild-type. Meiotic recombination is merely rearrange them and not generate new one that is different from the four. Terry Chow mdty@musica.mcgill.ca From owner-recombination@net.bio.net Tue Apr 29 23:00:00 1997 Path: biosci!bcm.tmc.edu!cs.utexas.edu!feeder.chicago.cic.net!news.uiowa.edu!news.physics.uiowa.edu!newsrelay.iastate.edu!news.iastate.edu!not-for-mail From: "Patrick S. Schnable" Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: Wed, 30 Apr 1997 12:12:55 -0500 Organization: Iowa State University Lines: 30 Message-ID: <33677CEF.14FB@iastate.edu> References: <3367431F.6AEC@osprey.unf.edu> NNTP-Posting-Host: pc2696.agron.iastate.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0Gold (Macintosh; U; PPC) > Dear John, > No. I'm sorry I was not more clear. Our concept of a crossover > is that it involves substantial lengths homologous sequences (hundreds > to thousands of base pairs) in which heteroduplex is formed and usually > corrected to give conversion. The process may also involve some deletion > and gap filling from the homologue, though this is not clear. The > resolution of this structure may result in a crossover i. e. reciprocal > recombination of flanking sequences. There is plenty of evidence in > yeast that, in meiosis,the event begins outside the gene at one end (often > but not always the promoter end). Thus one does not expect alleles to be > recombined by crossing-over. Tetrad analysis confirms this. > > Phil. Maybe I misunderstand you, but because the sites at which a crossover initiates and resolves are separate, intragenic recombination could occur even if initiation occurs outside of the gene. And indeed, we (Xu et al. 1995 Plant Cell 7:2151-2161) and others have very clear sequence data that demonstrates that crossing over can recombine sequence polymorphisms within alleles. -- Patrick S. Schnable Associate Professor G405 Agronomy Iowa State University Ames, IA 50011 USA 515-294-0975 (office) 515-294-2299 (fax) http://www.public.iastate.edu/~schnable/ From owner-recombination@net.bio.net Tue Apr 29 23:00:00 1997 Path: biosci!ODYSSEE.NET!dellaire From: dellaire@ODYSSEE.NET ("Graham Dellaire") Newsgroups: bionet.molbio.recombination Subject: ON the Issue of Heritable Mutation... Look at this article I found! Date: 30 Apr 1997 05:46:31 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 85 Sender: daemon@net.bio.net Distribution: world Message-ID: <97Apr30.084817-0400_edt.585875-32659+894@skywalker.microtec.net> NNTP-Posting-Host: net.bio.net Hello Everyone, On the subject of heritable mutations, new alleles and such look at the following paper. I find it very, very interesting. In particular this line in the abstract: "which is responsible for the NF1 phenotype in a kindred with two children affected because of germline mosaicism in the unaffected father, who has the mutation in 10% of his spermatozoa. " The father is not affected...meaning the mutation is in perhaps a clone of spermatagonia that had acquired the deletion. I think 10% would be too high for spontaneous mutation occuring during gametogenesis. see the following: Am J Hum Genet 57 (5): 1044-1049 (1995) Molecular characterization of the breakpoints of a 12-kb deletion in the NF1 gene in a family showing germ-line mosaicism. Lazaro C, Gaona A, Lynch M, Kruyer H, Ravella A, Estivill X Abstract Neurofibromatosis type 1 (NF1) is caused by deletions, insertions, translocations, and point mutations in the NF1 gene, which spans 350 kb on the long arm of human chromosome 17. Although several point mutations have been described, large molecular abnormalities have rarely been characterized in detail. We describe here the molecular breakpoints of a 12-kb deletion of the NF1 gene, which is responsible for the NF1 phenotype in a kindred with two children affected because of germline mosaicism in the unaffected father, who has the mutation in 10% of his spermatozoa. The mutation spans introns 31-39, removing 12,021 nt and inserting 30 bp, of which 19 bp are a direct repetition of a sequence located in intron 31, just 4 bp before the 5' breakpoint. The 5' and 3' breakpoints contain the sequence TATTTTA, which could be involved in the generation of the deletion. The most plausible explanation for the mechanism involved in the generation of this 12-kb deletion is homologous/nonhomologous recombination. Since sperm of the father does not contain the corresponding insertion of the 12-kb deleted sequence, this deletion could have occurred within the NF1 chromosome through loop formation. RNA from lymphocytes of one of the NF1 patients showed similar levels of the mutated and normal transcripts, suggesting that the NF1-mRNA from mutations causing frame shifts of the reading frame or stop codons in this gene is not degraded during its processing. The mutation was not detected in fresh lymphocytes from the unaffected father by PCR analysis, supporting the case for true germ-line mosaicism. ******************************************************** Cheers, Graham ===================================== | Graham Dellaire | | Division of Experimental Medicine | Dept of Medicine, McGill University |(http://www.medcor.mcgill.ca/EXPMED/expmed.html) | | e-mail: dellaire@odyssee.net | Fax: (514) 896 4689 | Vox: (514) 281 6000 ext. 6936 | | Bionet: bionet.molbio.recombination | bionet.genome.gene-structure ===================================== | Snail Mail: | Institut du Cancer de Montreal | Centre de Recherch L.C. Simard | 1560 Sherbrooke St. East | Montreal, Quebec, CANADA | H2L 4M1 ===================================== From owner-recombination@net.bio.net Tue Apr 29 23:00:00 1997 Path: biosci!GPU.SRV.UALBERTA.CA!hastings From: hastings@GPU.SRV.UALBERTA.CA (P Hastings) Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: 30 Apr 1997 07:32:37 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 28 Sender: daemon@net.bio.net Distribution: world Message-ID: References: <3367431F.6AEC@osprey.unf.edu> NNTP-Posting-Host: net.bio.net On 30 Apr 1997, John E. Anderson wrote: > P Hastings wrote: > > It is improbable that recombination between alleles occurs by > > crossing-over. A crossover occupies a length in which conversion occurs. > > Usually, one end of the length is outside the gene where the event is > > initiated. > > Do you mean that crossing over deletes some of the DNA? > > John > -- > John E. Anderson > jander@unf.edu Dear John, No. I'm sorry I was not more clear. Our concept of a crossover is that it involves substantial lengths homologous sequences (hundreds to thousands of base pairs) in which heteroduplex is formed and usually corrected to give conversion. The process may also involve some deletion and gap filling from the homologue, though this is not clear. The resolution of this structure may result in a crossover i. e. reciprocal recombination of flanking sequences. There is plenty of evidence in yeast that, in meiosis,the event begins outside the gene at one end (often but not always the promoter end). Thus one does not expect alleles to be recombined by crossing-over. Tetrad analysis confirms this. Phil. From owner-recombination@net.bio.net Tue Apr 29 23:00:00 1997 Path: biosci!OSPREY.UNF.EDU!jander From: jander@OSPREY.UNF.EDU ("John E. Anderson") Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: 30 Apr 1997 06:26:53 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 31 Sender: daemon@net.bio.net Distribution: world Message-ID: <33674889.60D1@osprey.unf.edu> References: <3366299D.7E8C@musica.mcgill.ca> NNTP-Posting-Host: net.bio.net Terry Chow wrote: >I just want to point out that, in a > way, the example you cited is in theory of four alleles. 3', 5', 3'-5', > and wild-type. Meiotic recombination is merely rearrange them and not > generate new one that is different from the four. I agree that the genes having the 3', 5', wt, and 3'-5' mutations are different alleles. But while the crossover does merely rearrange the already-mutated base pairs, in doing so it puts them both on the same chromosome, a situation that did not exist before, and thereby generates a new allele of the gene. I know this is getting tiresome. As somebody mentioned, it's really just a sloppy use of the term allele. But when discussing the sources of new alleles in a gene pool in an evolutionary sense, I think allele means a gene with a different DNA sequence (which may or may not have a different function). It is in this sense that the crossover in my example generates a new allele. So I think it is incorrect to say, in a textbook unit on evolution, that mutation is the only way to generate new alleles. There are, in fact, at least three ways: mutation, crossover, and changes in chromosome structure (deletions, transpositions, inversions, etc). Thanks to all for helping me figure this out. John -- John E. Anderson jander@unf.edu From owner-recombination@net.bio.net Tue Apr 29 23:00:00 1997 Path: biosci!OSPREY.UNF.EDU!jander From: jander@OSPREY.UNF.EDU ("John E. Anderson") Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: 30 Apr 1997 06:26:47 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 14 Sender: daemon@net.bio.net Distribution: world Message-ID: <3367431F.6AEC@osprey.unf.edu> References: NNTP-Posting-Host: net.bio.net P Hastings wrote: > It is improbable that recombination between alleles occurs by > crossing-over. A crossover occupies a length in which conversion occurs. > Usually, one end of the length is outside the gene where the event is > initiated. Do you mean that crossing over deletes some of the DNA? John -- John E. Anderson jander@unf.edu From owner-recombination@net.bio.net Wed Apr 30 23:00:00 1997 Path: biosci!GPU.SRV.UALBERTA.CA!hastings From: hastings@GPU.SRV.UALBERTA.CA (P Hastings) Newsgroups: bionet.molbio.recombination Subject: Re: location of crossovers with respect to coding sequences Date: 1 May 1997 07:38:03 -0700 Organization: BIOSCI International Newsgroups for Molecular Biology Lines: 53 Sender: daemon@net.bio.net Distribution: world Message-ID: References: <33677CEF.14FB@iastate.edu> NNTP-Posting-Host: net.bio.net On Wed, 30 Apr 1997, Patrick S. Schnable wrote: > > Dear John, > > No. I'm sorry I was not more clear. Our concept of a crossover > > is that it involves substantial lengths homologous sequences (hundreds > > to thousands of base pairs) in which heteroduplex is formed and usually > > corrected to give conversion. The process may also involve some deletion > > and gap filling from the homologue, though this is not clear. The > > resolution of this structure may result in a crossover i. e. reciprocal > > recombination of flanking sequences. There is plenty of evidence in > > yeast that, in meiosis,the event begins outside the gene at one end (often > > but not always the promoter end). Thus one does not expect alleles to be > > recombined by crossing-over. Tetrad analysis confirms this. > > > > Phil. > > Maybe I misunderstand you, but because the sites at which a crossover > initiates and resolves are separate, intragenic recombination could > occur even if initiation occurs outside of the gene. And indeed, we (Xu > et al. 1995 Plant Cell 7:2151-2161) and others have very clear sequence > data that demonstrates that crossing over can recombine sequence > polymorphisms within alleles. > > -- > Patrick S. Schnable > Associate Professor > G405 Agronomy > Iowa State University > Ames, IA 50011 USA > 515-294-0975 (office) > 515-294-2299 (fax) > http://www.public.iastate.edu/~schnable/ > Dear Patrick, I don't know how I got myself into this mess, But I think it is all to do with precisely what we mean by various words. I do not know your paper in plant cell, but I would be delighted if you sent me a copy because I have long felt that plant recombination is a neglected field. A crossover is, by definition, a reciprocal event. To demonstrate a crossover one must therefore recover both products of the same event. This can be done by tetrad analysis or by the use of attatched chromosomes. It can be done in mitosis by the use of twin spots. I expect that you know all this. My point is that use of these methods shows that recombination between alleles is almost always non reciprocal. We then say that it occurred by conversion, which is a catch-all term. Even when , rarely, one sees a reciprocal intragenic event, one does not really know that a whole crossover event was included between the allelic markers because there are various patterns of correction, migration, back-migration and resolution that can give the sme appearance. I had only raised the point because people seemed to be using the terms "recombination" and "crossover" as though they were synonymous wheras, in an intragenic situation they are certainly not. Phil Hastings, Biology Dept, U of Alberta, Edmonton.