Dear Stan,
I thought everyone should see your question, since I'm not an expert on how
hard or easy it is to work with a genome. If we assume that most of the DNA
in salamander huge genomes is "junk", perhaps there is a way to identify
and sequence only the "useful" part, perhaps starting with homologies? If
so, then we could begin a Urodele Genome Project. The advantage would be
that we would be dealing with a vertebrate that is not as specialized as,
say zebrafish, that is fundamentally similar to humans in its development
(unlike Xenopus), that has remarkable properties we wish humans could have
(limb and spinal cord regeneration, and partial brain transplantability),
that imitates major human birth defects, that has large cells (due to that
huge genome) that are accessible during embryogenesis (unlike mouse) and
relatively easy to follow and tamper with (unlike Drosphila and C.
elegans), lots of species for comparison and evolutionary studies (again,
unlike Xenopus), and has interesting prospects for behavior/geneome
correlations, etc.
Yours, -Dick Gordon
cc:
Ms. Betty K. Mansfield, Managing Editor
Human Genome News, Oak Ridge National Laboratory
1060 Commerce Park, MS 6480
Oak Ridge TN 37830, USA
Phone: (423) 576-6669, Fax: (423) 574-9888
E-mail: bkq at ornl.gov (Betty Mansfield)
>Dear Dick,
> I see. I was just going to respond to you but then I thought it
>might be
>good to put a plug in for giant salamander genomes in general. The genomes
>of many species of salamanders are so big that they are difficult to work
>with. But I wonder if their large size could actually prove an advantage
>in genome studies, somehow.
>>- Stan
>>----------
>From: Richard Gordon[SMTP:gordonr at cc.UManitoba.CA]
>Sent: Friday, February 26, 1999 5:51 PM
>To: Stanley K. Sessions
>Subject: RE: ambystomid protein coding loci/genome sizes
>>Dear Stan,
>I STANd corrected! I was thinking of urodeles relative to lungfish, not
>axolotls relative to other urodeles. Did you broadcast this to everyone?
>Not clear from the headings.
>Yours, -Dick
>>>Dear Dick,
>> I know this is a bit beside the main point, but A. mexicanum has
>>far from
>>the second largest genome among salamanders! Species with far greater
>>amounts of nuclear DNA than axolotls include sirenids, amphiumids,
>>cryptobranchids, dicamptodontids, and the most species of tropical and
>>temperate plethodontids (the largest salamander family).
>>>>Stan Sessions
>>Department of Biology
>>Hartwick College
>>Oneonta, NY 13820
>>(607) 431-4764
Dr. Richard Gordon, Radiology, U. Manitoba, HSC, 820 Sherbrook Street,
Winnipeg R3A 1R9 Canada, Phone: (204) 789-3828, fax: (204)
787-2080/forthcoming book: The Hierarchical Genome & Differentiation Waves:
Novel Unification of Development, Genetics & Evolution:
http://www.wspc.com.sg/books/lifesci/2755.html