title: Hypermutability of HoxA13A and functional divergence from its paralog are associated with the origin of a novel developmental feature in zebrafish and related taxa (Cypriniformes).
abstract: Gene duplication is widely regarded as the predominant mechanism by which genes with new functions and associated phenotypic novelties arise. A whole genome duplication occurred shortly before the most recent common ancestor of teleosts, the most diverse chordate group, resulting in duplication and retention of many Hox cluster genes. Because they play a key role in determination of body plan morphology, it has been widely assumed that Hox genes play a key role in the evolution of diverse metazoan body plans. However, it is not clear whether certain aspects of molecular evolution, such as asymmetric divergence and neofunctionalization, contribute to the initial retention of paralogs. We investigate the molecular evolution and functional divergence of the duplicated HoxA13 paralogs in zebrafish to determine when asymmetric divergence and functional divergence occurred after the duplication event. Our findings demonstrate the contribution of gene duplication to the evolution of novel features through evolutionary mechanisms other than those traditionally investigated, such as positive selection occurring immediately after gene duplication. Rather, we find a latent build up of molecular changes in a gene associated with the development of a novel feature in a very diverse group of fishes.
authors.affiliation: San Francisco State University, Department of Biology, 1600 Holloway Ave., San Francisco, California 94132, USA. crow@sfsu.edu
authors.forename: Karen D
authors.initials: KD
authors.lastname: Crow
authors.forename: Chris T
authors.initials: CT
authors.lastname: Amemiya
authors.forename: Jutta
authors.initials: J
authors.lastname: Roth
authors.forename: Günter P
authors.initials: GP
authors.lastname: Wagner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003531:Cypriniformes / Q000145:classification / Q000235:genetics / Q000254:growth & development; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000235:genetics*; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D049810:Genetic Speciation; D018398:Homeodomain Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics*; D012641:Selection, Genetic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development
chemical_list: D029941:Fish Proteins; D018398:Homeodomain Proteins; D020033:Protein Isoforms; C099959:homeobox protein HOXA13