title: Origin of metazoan cadherin diversity and the antiquity of the classical cadherin/β-catenin complex.
abstract: The evolution of cadherins, which are essential for metazoan multicellularity and restricted to metazoans and their closest relatives, has special relevance for understanding metazoan origins. To reconstruct the ancestry and evolution of cadherin gene families, we analyzed the genomes of the choanoflagellate Salpingoeca rosetta, the unicellular outgroup of choanoflagellates and metazoans Capsaspora owczarzaki, and a draft genome assembly from the homoscleromorph sponge Oscarella carmela. Our finding of a cadherin gene in C. owczarzaki reveals that cadherins predate the divergence of the C. owczarzaki, choanoflagellate, and metazoan lineages. Data from these analyses also suggest that the last common ancestor of metazoans and choanoflagellates contained representatives of at least three cadherin families, lefftyrin, coherin, and hedgling. Additionally, we find that an O. carmela classical cadherin has predicted structural features that, in bilaterian classical cadherins, facilitate binding to the cytoplasmic protein β-catenin and, thereby, promote cadherin-mediated cell adhesion. In contrast with premetazoan cadherin families (i.e., those conserved between choanoflagellates and metazoans), the later appearance of classical cadherins coincides with metazoan origins.
authors: Department of Biological Sciences, University of Denver, Denver, CO 80208, USA.
authors: Scott Anthony
authors: SA
authors: Nichols
authors: Brock William
authors: BW
authors: Roberts
authors: Daniel Joseph
authors: DJ
authors: Richter
authors: Stephen Robert
authors: SR
authors: Fairclough
authors: Nicole
authors: N
authors: King
mesh_terms: D000818:Animals; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics*; D056897:Choanoflagellata / Q000235:genetics*; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D016678:Genome / Q000235:genetics; D015698:Genomic Library; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D051176:beta Catenin / Q000235:genetics*
chemical_list: D015820:Cadherins; D017931:DNA Primers; D051176:beta Catenin