[Annelida] Lab populations: Lessons from leeches
(by abely At umd.edu)
Fri Nov 3 00:39:54 EST 2006
Regarding our paper on Helobdella leeches that was recently
highlighted by Geoff, I would like to clarify that our record of the
alien invasive Helobdella europaea (= H. papillornata) from North
America is based primarily on our (repeated) collections of this
species from ponds and ditches at a fish farm near Galt, California
(USA!), not just our collection from the roof-top pond noted in
I would be happy to send a reprint of our paper to anyone interested.
I certainly wish I had caught the unfortunate omission from our
abstract of "the country" 's name. Being an alien invasive myself
(from France), I am normally very sensitive to US-centrism! My own
lesson from "Lessons from leeches" will be to read, re-read, and
>There are some interesting results in this paper for those interested in
>cryptic species and also peripherally alien invasives. The unnamed
>country referred to in the abstract might be the one south of Canada
>and north of Mexico, but that's just speculation on my part. :^)
>Bely, Alexandra E. & Weisblat, David A. (2006)
>Lessons from leeches: a call for DNA barcoding in the lab.
>Evolution & Development 8 (6), 491-501.
>Many evolution of development labs study organisms that must be
>periodically collected from the wild. Whenever this is the case, there
>is the risk that different field collections will recover genetically
>different strains or cryptic species. Ignoring this potential for
>genetic variation may introduce an uncontrolled source of experimental
>variability, leading to confusion or misinterpretation of the results.
>Leeches in the genus Helobdella have been a workhorse of annelid
>developmental biology for 30 years. Nearly all early Helobdella research
>was based on a single isolate, but in recent years isolates from
>multiple field collections and multiple sites across the country have
>been used. To assess the genetic distinctness of different isolates, we
>obtained specimens from most Helobdella laboratory cultures currently or
>recently in use and from some of their source field sites. From these
>samples, we sequenced part of the mitochondrial gene cytochrome oxidase
>I (COI). Sequence divergences and phylogenetic analyses reveal that,
>collectively, the Helobdella development community has worked on five
>distinct species from two major clades. Morphologically similar isolates
>that were thought to represent the same species (H. robusta) actually
>represent three species, two of which coexist at the same locality.
>Another isolate represents part of a species complex (the "H.
>triserialis" complex), and yet another is an invasive species (H.
>europaea). We caution researchers similarly working on multiple
>wild-collected isolates to preserve voucher specimens and to obtain from
>these a molecular "barcode," such as a COI gene sequence, to reveal
>genetic variation in animals used for research
>For those interested in aliens the authors record Helobdella europaea
>from North America for the first time (although despite the name it
>could have originated in South America). Here's what the authors say:
>"Consistent with its propensity to be dispersed by humans,
>H. europaea was discovered in an artificial pond used
>for holding various aquatic animals of diverse geographic origins
>on the roof of a UC Berkeley laboratory building."
>In the same issue:
>Mitogenomics and phylogenomics reveal priapulid worms as extant models
>of the ancestral Ecdysozoan
>Bonnie L. Webster, Richard R. Copley, Ronald A. Jenner, Jacqueline A.
>Mackenzie-Dodds, Sarah J. Bourlat, Omar Rota-Stabelli, D. T. J.
>Littlewood, Maximilian J. Telford
>Evolution & Development;
>Volume 8, Issue 6, 2006Nov1, Page 502
> Geoff Read <g.read At niwa.co.nz>
>Annelida mailing list
>Post: Annelida At net.bio.net
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Department of Biology
University of Maryland
College Park, MD 20742-4415 USA
email: abely At umd.edu
phone: (301) 405-0225
office: 0220 Biology/Psychology Bldg
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