title: Evolutionary pathway of pseudogenization of globin genes, α5 and β5, in genus Oryzias.
abstract: Hemoglobin transports oxygen in many organisms and consists of α- and β-globin chains. Previously, using molecular phylogenetic analysis, we proposed that both α- and β-globins of teleost could be classified into four groups. We also showed that the Hd-rR strain of medaka (Oryzias latipes) inhabiting southern Japan had all four groups of globin genes but that the α- and β-globin genes of group III were pseudogenized (α5(ψα), β5(ψβ)). Based on the small degree of nucleotide variations, the pseudogenization of β5 was assumed to have occurred at a relatively late stage of evolution. Here, we compared the α5(ψα)-β5(ψβ) of two other strains of O. latipes and found that both α5(ψα) and β5(ψβ) of the northern Japanese and Korean strains were pseudogenized similar to those of Hd-rR. In a Philippine population (Oryzias luzonensis), α5(ψα) was also pseudogenized, but the structure was different from that of O. latipes, and β5(ψβ) was almost deleted. Interestingly, an Indonesian population (Oryzias celebensis) had α5 and β5 genes that were deduced to be functional. Indeed, they were expressed from the young to adult development stages, and this expression pattern was consistent with the expression of α2 and ad.α1 in Hd-rR. Because α2 and ad.α1 in Hd-rR were assigned to groups I and II, respectively, we speculate that their expression patterns might be altered by pseudogenization of group III genes. These results provide a basis for further investigations of recruiting and changing expression patterns of one globin gene after pseudogenization of other globin genes during evolution.
authors.affiliation: Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan. k_maruya@nirs.go.jp.|Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan. k_maruya@nirs.go.jp.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Maruyama
authors.affiliation: Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.affiliation: Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Yasumasu
authors.affiliation: Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Iuchi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics*; D005914:Globins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009990:Oryzias / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D029941:Fish Proteins; D005914:Globins
keywords: Hemoglobin; Medaka; Oryzias; Pseudogene