Meeting Abstract
109.3 Tuesday, Jan. 7 08:30 The Genome of the Ctenophore Mnemiopsis leidyi: Bringing Resolution to the Phylogenetic Position of the Ctenophores RYAN, J.F.; SCHNITZLER, C.E.; MAXWELL, E.K.; PANG, K.; FRANCIS, W.R.; SMITH, S.A.; WOLFSBERG, T.G.; MULLIKIN, J.C.; HADDOCK, S.H.D.; DUNN, C.W.; MARTINDALE, M.Q.; BAXEVANIS, A.D.*; NHGRI/NIH and Sars Intl. Centre for Marine Mol. Biol.; Natl. Human Genome Res. Inst., NIH; Natl. Human Genome Res. Inst., NIH; Sars Intl. Centre for Marine Mol. Biol.; Monterey Bay Aquarium Res. Inst.; Brown Univ.; Natl. Human Genome Res. Inst., NIH; Natl. Human Genome Res. Inst., NIH; Monterey Bay Aquarium Res. Inst.; Brown Univ.; Whitney Lab for Marine Bioscience, Univ. of Florida; Natl. Human Genome Res. Inst., NIH andy@mail.nih.gov
Until recently, Ctenophora (comb jellies) was the only non-bilaterian animal phylum without a sequenced genome, and its phylogenetic position has remained highly controversial. To understand the molecular innovations that drove the outbreak of diversity in the early evolution of animals, we have sequenced, assembled, annotated, and analyzed the 150 megabase genome of the ctenophore, Mnemiopsis leidyi. Our analyses of these data from both a gene content and a traditional concatenated phylogenomic perspective strongly suggest that ctenophores are sister to all other animals. The implications of these results are either that neural and mesodermal cell types were lost in Porifera and Placozoa, or that (to some extent) these cell types evolved independently in the ctenophore lineage. The inventory of genes associated with these cell types in both Mnemiopsis and the deeply sequenced transcriptomes of seven other ctenophores supports the possibility of some degree of independent evolution. We have also used these data to assess the role of these animals in furthering human disease research; using a comparative genomics approach, we find that non-bilaterian animals have the potential to serve as viable models for studying various important classes of human diseases.
