Expression of a Hox gene, Cnox-2, and the division of labor in a colonial hydroid

Expression of a Hox gene, Cnox-2, and the division of labor in a colonial hydroid

Departments of ^*Biology, ^§Ecology & Evolutionary Biology, and ^¶Geology and Geophysics, Yale University, New Haven, CT 06520

Communicated by Stephen Jay Gould, Harvard University, Cambridge, MA (received for review May 1, 1998)

Abstract

We report the isolation and expression of the Hox gene, Cnox-2, in Hydractinia symbiolongicarpus, a hydrozoan displaying division of labor. We found different patterns of aboral-to-oral Cnox-2 expression among polyp polymorphs, and we show that experimental conversion of one polyp type to another is accompanied by concordant alteration in Cnox-2 expression. Our results are consistent with the suggestion that polyp polymorphism, characteristic of hydractiniid hydroids, arose via evolutionary modification of proportioning of head to body column.

Footnotes

↵ † To whom reprint requests should be addressed. e-mail: pcart{at}eagle.cc.ukans.edu.
↵ ‡ Present address: Division of Biological Sciences, University of Kansas, Lawrence, KS 66045.
Data deposition: The sequence reported in this paper has been deposited in the GenBank database (accession no. AF031953).