title: Molecular Polymorphism and Divergence of Duplicated Genes in Tetraploid African Clawed Frogs (Xenopus).
abstract: Genome duplication creates redundancy in proteins and their interaction networks, and subsequent smaller-scale gene duplication can further amplify genetic redundancy. Mutations then lead to the loss, maintenance or functional divergence of duplicated genes. Genome duplication occurred many times in African clawed frogs (genus Xenopus), and almost all extant species in this group evolved from a polyploid ancestor. To better understand the nature of selective constraints in a polyploid genome, we examined molecular polymorphism and divergence of duplicates and single-copy genes in 2 tetraploid African clawed frog species, Xenopus laevis and X. victorianus. We found that molecular polymorphism in the coding regions of putative duplicated genes was higher than in singletons, but not significantly so. Our findings also suggest that transcriptome evolution in polyploids is influenced by variation in the genome-wide mutation rate, and do not reject the hypothesis that gene dosage balance is also important.
authors.affiliation: Department of Biology, McMaster University, Hamilton, Ont., Canada.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Evans
authors.forename: Taejoon
authors.initials: T
authors.lastname: Kwon
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D018628:Gene Dosage; D020440:Gene Duplication; D008957:Models, Genetic; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic / Q000235:genetics*; D057891:Tetraploidy; D020506:Untranslated Regions / Q000235:genetics; D014981:Xenopus / Q000235:genetics*
chemical_list: D020506:Untranslated Regions