Evidence from Hox genes that bryozoans are lophotrochozoans.
Bryozoans, or moss animals, are small colonial organisms that possess a suspension-feeding apparatus called a lophophore. Traditionally, this "phylum" has been grouped with brachiopods and phoronids because of the feeding structure. Available molecular and morphological data refute this notion of a monophyletic "Lophophorata." Alternative hypotheses place bryozoans either at the base of the Lophotrochozoa or basal to the Lophotrochozoa/Ecdysozoa split. Surprisingly, the only molecular data bearing on this issue are from the 18S nuclear ribosomal gene. Here we report the results of a Hox gene survey using degenerate polymerase chain reaction primers in a gymnolaemate bryozoan, Bugula turrita. Putative orthologs to both the Post2 and the Lox5 genes were found, suggesting that bryozoans are not a basal protostome group but closely allied to other lophotrochozoan taxa. We also found the first definitive evidence of two Deformed/Hox4 class genes in a nonvertebrate animal.
Passamaneck
Yale J
YJ
Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
Halanych
Kenneth M
KM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D002013:Bryozoa / Q000235:genetics*; D017931:DNA Primers; D018398:Homeodomain Proteins / Q000235:genetics*; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D017931:DNA Primers; D018398:Homeodomain Proteins