title: Meiotic recombination counteracts male-biased mutation (male-driven evolution).
abstract: Meiotic recombination is believed to produce greater genetic variation despite the fact that deoxyribonucleic acid (DNA)-replication errors are a major source of mutations. In some vertebrates, mutation rates are higher in males than in females, which developed the theory of male-driven evolution (male-biased mutation). However, there is little molecular evidence regarding the relationships between meiotic recombination and male-biased mutation. Here we tested the theory using the frog Rana rugosa, which has both XX/XY- and ZZ/ZW-type sex-determining systems within the species. The male-to-female mutation-rate ratio (α) was calculated from homologous sequences on the X/Y or Z/W sex chromosomes, which supported male-driven evolution. Surprisingly, each α value was notably higher in the XX/XY-type group than in the ZZ/ZW-type group, although α should have similar values within a species. Interestingly, meiotic recombination between homologous chromosomes did not occur except at terminal regions in males of this species. Then, by subdividing α into two new factors, a replication-based male-to-female mutation-rate ratio (β) and a meiotic recombination-based XX-to-XY/ZZ-to-ZW mutation-rate ratio (γ), we constructed a formula describing the relationship among a nucleotide-substitution rate and the two factors, β and γ. Intriguingly, the β- and γ-values were larger and smaller than 1, respectively, indicating that meiotic recombination might reduce male-biased mutations.
authors.affiliation: Department of Biosciences, School of Science, Kitasato University, Kitasato 1-15-1, Minamiku, Sagamihara 252-0373, Japan.
authors.forename: Shuuji
authors.initials: S
authors.lastname: Mawaribuchi
authors.affiliation: Department of Biosciences, School of Science, Kitasato University, Kitasato 1-15-1, Minamiku, Sagamihara 252-0373, Japan ito@sci.kitasato-u.ac.jp.
authors.forename: Michihiko
authors.initials: M
authors.lastname: Ito
authors.affiliation: Laboratory of Zoo Biology, Preservation and Research Center, Kawaishukucho 155-1, Asahiku, Yokohama 241-0804, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Ogata
authors.affiliation: Laboratory of Genome Anthropology, Department of Anatomy, Kitasato University School of Medicine, Kitasato 1-15-1, Minamiku, Sagamihara 252-0674, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Oota
authors.affiliation: Laboratory of Genome Anthropology, Department of Anatomy, Kitasato University School of Medicine, Kitasato 1-15-1, Minamiku, Sagamihara 252-0674, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Katsumura
authors.affiliation: Department of Biosciences, School of Science, Kitasato University, Kitasato 1-15-1, Minamiku, Sagamihara 252-0373, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Takamatsu
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashihiroshima 739-8526, Japan imiura@hiroshima-u.ac.jp.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Miura
mesh_terms: D063147:Animal Distribution; D000818:Animals; D005075:Biological Evolution; D005260:Female; D007564:Japan; D008297:Male; D008540:Meiosis; D009154:Mutation; D010802:Phylogeny; D011898:Ranidae / Q000235:genetics* / Q000502:physiology; D011995:Recombination, Genetic / Q000502:physiology*; D012730:Sex Chromosomes / Q000235:genetics*
keywords: germ cell; male-biased mutation; male-driven evolution; meiotic recombination; mutation rate; sex chromosome