| RRC ID |
65983
|
| 著者 |
Yamamoto K, Hamaji T, Kawai-Toyooka H, Matsuzaki R, Takahashi F, Nishimura Y, Kawachi M, Noguchi H, Minakuchi Y, Umen JG, Toyoda A, Nozaki H.
|
| タイトル |
Three genomes in the algal genus Volvox reveal the fate of a haploid sex-determining region after a transition to homothallism.
|
| ジャーナル |
Proc Natl Acad Sci U S A
|
| Abstract |
Transitions between separate sexes (dioecy) and other mating systems are common across eukaryotes. Here, we study a change in a haploid dioecious green algal species with male- and female-determining chromosomes (U and V). The genus Volvox is an oogamous (with large, immotile female gametes and small, motile male gametes) and includes both heterothallic species (with distinct male and female genotypes, associated with a mating-type system that prevents fusion of gametes of the same sex) and homothallic species (bisexual, with the ability to self-fertilize). We date the origin of an expanded sex-determining region (SDR) in Volvox to at least 75 Mya, suggesting that homothallism represents a breakdown of dioecy (heterothallism). We investigated the involvement of the SDR of the U and V chromosomes in this transition. Using de novo whole-genome sequences, we identified a heteromorphic SDR of ca 1 Mbp in male and female genotypes of the heterothallic species Volvox reticuliferus and a homologous region (SDLR) in the closely related homothallic species Volvox africanus, which retained several different hallmark features of an SDR. The V. africanus SDLR includes a large region resembling the female SDR of the presumptive heterothallic ancestor, whereas most genes from the male SDR are absent. However, we found a multicopy array of the male-determining gene, MID, in a different genomic location from the SDLR. Thus, in V. africanus, an ancestrally female genotype may have acquired MID and thereby gained male traits.
|
| 巻・号 |
118(21)
|
| 公開日 |
2021-5-25
|
| DOI |
10.1073/pnas.2100712118
|
| PII |
2100712118
|
| PMID |
34011609
|
| PMC |
PMC8166075
|
| MeSH |
Algal Proteins
Biological Evolution
Chromosome Mapping
Genome*
Germ Cells
Haploidy*
Phylogeny*
Reproduction
Volvox / classification
Volvox / genetics*
|
| IF |
9.412
|
| リソース情報 |
| 藻類 |
NIES-3780
NIES-3781
NIES-3782
NIES-3783
NIES-3784
NIES-3785
NIES-3786 |
