title: The genome of the ctenophore Mnemiopsis leidyi and its implications for cell type evolution.
abstract: An understanding of ctenophore biology is critical for reconstructing events that occurred early in animal evolution. Toward this goal, we have sequenced, assembled, and annotated the genome of the ctenophore Mnemiopsis leidyi. Our phylogenomic analyses of both amino acid positions and gene content suggest that ctenophores rather than sponges are the sister lineage to all other animals. Mnemiopsis lacks many of the genes found in bilaterian mesodermal cell types, suggesting that these cell types evolved independently. The set of neural genes in Mnemiopsis is similar to that of sponges, indicating that sponges may have lost a nervous system. These results present a newly supported view of early animal evolution that accounts for major losses and/or gains of sophisticated cell types, including nerve and muscle cells.
authors: Genome Technology Branch, Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors: Joseph F
authors: JF
authors: Ryan
authors: Kevin
authors: K
authors: Pang
authors: Christine E
authors: CE
authors: Schnitzler
authors: Anh-Dao
authors: AD
authors: Nguyen
authors: R Travis
authors: RT
authors: Moreland
authors: David K
authors: DK
authors: Simmons
authors: Bernard J
authors: BJ
authors: Koch
authors: Warren R
authors: WR
authors: Francis
authors: Paul
authors: P
authors: Havlak
authors: Stephen A
authors: SA
authors: Smith
authors: Nicholas H
authors: NH
authors: Putnam
authors: Steven H D
authors: SH
authors: Haddock
authors: Casey W
authors: CW
authors: Dunn
authors: Tyra G
authors: TG
authors: Wolfsberg
authors: James C
authors: JC
authors: Mullikin
authors: Mark Q
authors: MQ
authors: Martindale
authors: Andreas D
authors: AD
authors: Baxevanis
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D019070:Cell Lineage / Q000235:genetics*; D037302:Ctenophora / Q000145:classification / Q000166:cytology* / Q000235:genetics*; D016678:Genome; D008648:Mesoderm / Q000166:cytology; D008969:Molecular Sequence Data; D024510:Muscle Development / Q000235:genetics; D055495:Neurogenesis / Q000235:genetics; D010802:Phylogeny