title: Evolutionary origins of the transforming growth factor-beta gene family.
abstract: A molecular phylogeny for the transforming growth factor-beta (TGF-beta) gene family based on a comparison of nucleotide sequences is proposed. A phylogenetic tree constructed from these sequences shows that the family evolved from a common ancestral gene that came into existence at about the time of arthropod and chordate divergence. This model suggests that the present day TGF-beta gene family consists of four members: TGF-beta 1 (= TGF-beta 4), TGF-beta 2, TGF-beta 3, and TGF-beta 5. The molecular phylogeny and Southern hybridization data also suggest that the proteins for mammalian TGF-beta 1 and chicken TGF-beta 4 are the products of homologous rather than duplicated genes. If the gene duplication event that produced the ancestral gene for TGF-beta 1 occurred before the divergence of birds and mammals, then sufficient time would have elapsed to generate these quite distinct avian and mammalian TGF-beta 1 proteins. Therefore, the TGF-beta family contains four distinct proteins, TGF-beta 1, 2, 3, and 5.
authors.affiliation: Department of Cellular and Molecular Biology, AFRC Institute of Animal Physiology and Genetics Research, Roslin, Midlothian, UK.
authors.forename: D W
authors.initials: DW
authors.lastname: Burt
authors.forename: I R
authors.initials: IR
authors.lastname: Paton
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002645:Chickens / Q000235:genetics; D004247:DNA; D006801:Humans; D007700:Kinetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D017385:Sequence Homology; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000235:genetics*
chemical_list: D016212:Transforming Growth Factor beta; D004247:DNA