Turnover of Sex Chromosomes in Celebensis Group Medaka Fishes.
Turnover of Sex Chromosomes in Celebensis Group Medaka Fishes.
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DOI：
10.1534/g3.115.021543
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发表时间：
2015-10-23
期刊：
影响因子：
--
通讯作者：
Sakaizumi M
中科院分区：
文献类型：
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作者：
Myosho T;Takehana Y;Hamaguchi S;Sakaizumi M
脊椎动物的性染色体和性别决定（SD）基因是可变的。特别是Oryzias属的青鳉鱼在性染色体和SD基因方面表现出极大的多样性，为研究它们更替的进化过程提供了一个很好的模型。在这里，我们研究了六个 celebsis 类物种的性别决定系统和性染色体。我们的性别连锁分析表明，所有物种都具有 XX-XY 性别决定系统，并且 Oryzias marmoratus 和 O. profundicola 性染色体与 O. latipes 连锁群 (LG) 10 同源，而其他四个物种 O. celebensis、O. matanensis、O. wolasi 和 O. woworae 的性染色体与 O. latipes LG 24 同源。 系统发育关系表明，该群体内的性染色体从 O. latipes LG 24 转变为 LG 10。 6张性别连锁图显示，前两个和后四个物种分别具有共同的SD位点，表明LG 24在celebensis群体的共同祖先中获得了SD功能，而LG 10 SD功能在O. matanensis分化后出现在O. marmoratus和O. profundicola的共同祖先中。此外，前两个物种的精细作图和关联分析表明，Y 染色体上的 Sox3 是 SD 基因的主要候选者，并且 Y 特异性 430 bp 插入可能与其 SD 功能有关。
Sex chromosomes and the sex-determining (SD) gene are variable in vertebrates. In particular, medaka fishes in the genus Oryzias show an extremely large diversity in sex chromosomes and the SD gene, providing a good model to study the evolutionary process by which they turnover. Here, we investigated the sex determination system and sex chromosomes in six celebensis group species. Our sex-linkage analysis demonstrated that all species had an XX-XY sex determination system, and that the Oryzias marmoratus and O. profundicola sex chromosomes were homologous to O. latipes linkage group (LG) 10, while those of the other four species, O. celebensis, O. matanensis, O. wolasi, and O. woworae, were homologous to O. latipes LG 24. The phylogenetic relationship suggested a turnover of the sex chromosomes from O. latipes LG 24 to LG 10 within this group. Six sex-linkage maps showed that the former two and the latter four species shared a common SD locus, respectively, suggesting that the LG 24 acquired the SD function in a common ancestor of the celebensis group, and that the LG 10 SD function appeared in a common ancestor of O. marmoratus and O. profundicola after the divergence of O. matanensis. Additionally, fine mapping and association analysis in the former two species revealed that Sox3 on the Y chromosome is a prime candidate for the SD gene, and that the Y-specific 430-bp insertion might be involved in its SD function.