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 (a) was calculated from homologous sequences on the X/Y or Z/W sex chromosomes, which supported male-driven evolution. Surprisingly, each a value was notably higher in the XX/XY-type group than in the ZZ/ZW-type group, although a 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 a into two new factors, a replication-based male-to-female mutation-rate ratio (b) and a meiotic recombination-based XX-to-XY/ZZ-to-ZW mutation-rate ratio (g), we constructed a formula describing the relationship among a nucleotide-substitution rate and the two factors, b and g. Intriguingly, the b-and g-values were larger and smaller than 1, respectively, indicating that meiotic recombination might reduce male-biased mutations.

Origin of sex chromosomes in six groups of Rana rugosa frogs inferred from a sex‐linked DNA marker

“…() reported a distribution of R. rugosa , based on the morphology of the sex chromosomes in frogs collected from 24 sites in Japan. Recently, Miura and co‐workers reported two different distribution maps of R. rugosa frogs but without showing any sampling sites of the frogs (Mawaribuchi et al., ; Miura, Ohtani, Ogata, & Ezaz, ). To clarify the origin of the sex chromosomes in the different groups, it is necessary to have a refined map of the distribution in Japan of R. rugosa with genetically different backgrounds.…”

Parallel Evolution of Two dmrt1-Derived Genes, dmy and dm-W, for Vertebrate Sex Determination

“…It is believed that dmy and dm-W have evolved under recombination suppression. We previously reported that recombination suppression might lead to accumulation of DNA replication errors during population and species diversification (Mawaribuchi et al., 2016). Therefore, it is possible that amino acid substitutions might occur with increased frequency under the suppression of recombination.…”

Genetic and morphological variation analyses of Glandirana rugosa with description of a new species (Anura, Ranidae)

“…Although the East group of G. rugosa has no unique adult morphology sharply distinguishing all the other groups, it had significantly less 0761-0770, 1168, 2025, 2032, 2033, 2037, 2038, 2047, 2141, 2142, 2324, 2326-2331, 2333-2336 Etymology. The specific epithet is from a Latin noun denoting relic, alluding to the facts that the species represents a basic stock of Japanese Glandirana existing far before the western G. rugosa was derived and leaves a part of its own genome within the heteromorphic sex chromosomes of G. rugosa (Miura et al 1998;Miura 2007;Mawaribuchi et al 2016).…”