Structural changes in female-to-male sex-reversing gonads of Rana rugosa
Structural changes in female-to-male sex-reversing gonads of Rana rugosa
复制标题
林蛙雌雄逆转性腺的结构变化
DOI：
10.1002/jez.2009
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Masahisa Nakamura
中科院分区：
文献类型：
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作者：
Daiki Sakamoto;Ayumi Cho;Taishiro Abe;Yoriko Nakamura;Akira Oike;Maho Kodama;Masahisa Nakamura
许多两栖动物的性别表型可以被类固醇激素逆转。然而，这一过程的机制在很大程度上仍然未知。作为了解两栖动物性逆转过程中组织学变化的一步，我们分析了皱纹蛙性逆转性腺的二维和三维（2D和3D）结构。2D视图显示，野生型卵巢中的许多卵母细胞在雌性到雄性的性逆转过程中消失，伴随着Vasa阳性小生殖细胞的出现。部分生殖细胞用BrdU标记。在第8天和第16天，睾酮（T）处理的卵巢中BrdU阳性生殖细胞很少，这与野生型卵巢相似。在T处理的卵巢中，基底膜在第24天被破坏。然而，在T处理后40天，膜随后被重新配置为睾丸样性腺结构。使用连续免疫染色切片的性逆转性腺3D成像显示，T处理后24天，生殖细胞以线性方式组织，从性逆转性腺附着到睾丸系膜的地方延伸出来。生殖细胞的数量增加了40天，并定位于性腺的皮质。在第24天未接受T处理的睾丸中，许多生殖细胞分布在除中央空间外的整个皮质中，而输出管在两层睾丸间膜之间。这些结果表明，睾丸系膜在睾丸结构的组织中起着重要的作用。这是第一份报告显示生殖细胞个体发育和组织在雌性到雄性的性别逆转性腺在脊椎动物物种。
The phenotypic sex of many species of amphibians is subject to reversal by steroid hormones. The mechanism of this process, however, still remains largely unknown. As a step toward understanding the histological changes during sex reversal in amphibians, we analyzed two‐ and three‐dimensional (2D and 3D) structures of sex‐reversing gonads inRana rugosafrogs. 2D views revealed that many oocytes in the wild‐type ovary disappeared during female‐to‐male sex‐reversal concomitant with the emergence of Vasa‐positive small germ cells. Some of the germ cells were labeled with BrdU. BrdU‐positive germ cells were few in the testosterone (T) treated ovaries at days 8 and 16, which resembled wild‐type ovaries. Basement membranes became disrupted by day 24 in T‐treated ovaries. However, the membranes were later reconfigured into testis‐like gonadal structures 40 days after T treatment. 3D imaging of the sex‐reversing gonad using serial immunostained sections showed that germ cells were organized in linear fashion extending out from where the sex‐reversing gonad attached to the mesorchium 24 days after T treatment. Germ cells were increased in number by 40 days and were localized to the cortex of the gonads. In a T‐untreated testis at day 24, many germ cells were distributed throughout the cortex except in the central space, while the efferent duct ran between two sheets of the mesorchium. These results, taken together, suggest that the mesorchium plays an important role in the organization of testicular structure. This is the first report showing germ cell ontogeny and organization in the female‐to‐male sex‐reversing gonad in a vertebrate species.