The Cnidarian-Bilaterian Ancestor Possessed at Least 56 Homeoboxes: Evidence from the Starlet Sea Anemone, Nematostella vectensis
Date
2006-07-24
Authors
Ryan, Joseph F.
Burton, Patrick M.
Mazza, Maureen E.
Kwong, Grace K.
Mullikin, James C.
Finnerty, John R.
Version
OA Version
Citation
Ryan, Joseph F, Patrick M Burton, Maureen E Mazza, Grace K Kwong, James C Mullikin, John R Finnerty. "The Cnidarian-Bilaterian Ancestor Possessed at Least 56 Homeoboxes: Evidence from the Starlet Sea Anemone, Nematostella vectensis" Genome Biology 7(7):R64. (2006)
Abstract
The first near-complete set of homeodomains from a non-bilaterian animal is described. BACKGROUND. Homeodomain transcription factors are key components in the developmental toolkits of animals. While this gene superclass predates the evolutionary split between animals, plants, and fungi, many homeobox genes appear unique to animals. The origin of particular homeobox genes may, therefore, be associated with the evolution of particular animal traits. Here we report the first near-complete set of homeodomains from a basal (diploblastic) animal. RESULTS. Phylogenetic analyses were performed on 130 homeodomains from the sequenced genome of the sea anemone Nematostella vectensis along with 228 homeodomains from human and 97 homeodomains from Drosophila. The Nematostella homeodomains appear to be distributed among established homeodomain classes in the following fashion: 72 ANTP class; one HNF class; four LIM class; five POU class; 33 PRD class; five SINE class; and six TALE class. For four of the Nematostella homeodomains, there is disagreement between neighbor-joining and Bayesian trees regarding their class membership. A putative Nematostella CUT class gene is also identified. CONCLUSION. The homeodomain superclass underwent extensive radiations prior to the evolutionary split between Cnidaria and Bilateria. Fifty-six homeodomain families found in human and/or fruit fly are also found in Nematostella, though seventeen families shared by human and fly appear absent in Nematostella. Homeodomain loss is also apparent in the bilaterian taxa: eight homeodomain families shared by Drosophila and Nematostella appear absent from human (CG13424, EMXLX, HOMEOBRAIN, MSXLX, NK7, REPO, ROUGH, and UNC4), and six homeodomain families shared by human and Nematostella appear absent from fruit fly (ALX, DMBX, DUX, HNF, POU1, and VAX).
Description
License
Copyright 2006 Ryan et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.