antiquity of segmentation

[Bill Shear <bills@xxxxxxxxxxxxx>]

Last week a very exciting and interesting article and commentary appeared
in SCIENCE showing the possible homology of segmentation genes in
arthropods and chordates. DiRobertis, in a commentary, proposed that
segmentation therefore would have to have been a property of the common
ancestor of protostomes and deuterostomes.  He went on to list a number
other properties this hypothetical ancester would have to have had,
suggesting that it would have been much more complex than originally
envisioned.

Has anyone else been following this work?  Have the relevant genes been
searched for in, for instance, echinoderms or hemichordates?

Bill Shear
Department of Biology
Hampden-Sydney College
Hampden-Sydney VA 23943
(804)223-6172
FAX (804)223-6374
email<bills@tiger.hsc.edu>