The homeodomain complement of the ctenophore Mnemiopsis leidyi suggests that Ctenophora and Porifera diverged prior to the ParaHoxozoa

Table 2 Paralog count and estimated branch lengths of seven species.

Species	No. of HDs in this test	No. of HDs in species-specific clades	No. of species-specific clades	Average branch length
Nematostella vectensis	127	66	22	1.010
Drosophila melanogaster	102	25	12	1.052
Trichoplax adhaerens	35	0	0	1.162
Amphimedon queenslandica	31	7	2	1.286
Homo sapiens	256	197	74	1.293
Mnemiopsis leidyi	76	45	14	1.344
Caenorhabditis elegans	113	34	11	1.480
Average	105.71	53.43	19.29	1.232

The second column specifies the number of homeodomains (HDs) used in the neighbor-joining analyses that produced the tree from which this table is based. The third column indicates the number of homeodomains that were more closely related to a homeodomain from the same species. The number of species-specific clades is denoted in the fourth column. The final column shows the average length of all branches from a particular species based on a midpoint rooted tree. Files used in this analysis are (Additional File 2).

ISSN: 2041-9139