Anti-Müllerian hormone (Amh, or Müllerian-inhibiting substance, Mis), a member of TGF-β superfamily, has been well documented in some vertebrates as initiator or key regulator in sexual development, and particularly in fish. However, its functional role has not yet been identified in reptiles. Here, we characterized the Amh gene in the Chinese soft-shelled turtle Pelodiscus sinensis, a typical reptilian species exhibiting ZZ/ZW sex chromosomes. The messenger RNA of Amh was initially expressed in male embryonic gonads by stage 15, preceding gonadal sex differentiation, and exhibited a male-specific expression pattern throughout embryogenesis. Moreover, Amh was rapidly upregulated during female-to-male sex reversal induced by aromatase inhibitor letrozole. Most importantly, Amh loss of function by RNA interference led to complete feminization of genetic male (ZZ) gonads, suppression of the testicular marker Sox9, and upregulation of the ovarian regulator Cyp19a1 Conversely, overexpression of Amh in ZW embryos resulted in female-to-male sex reversal, characterized by the formation of a testis structure, ectopic activation of Sox9, and a remarkable decline in Cyp19a1 Collectively, these findings provide the first solid evidence that Amh is both necessary and sufficient to drive testicular development in a reptilian species, P. sinensis, highlighting the significance of the TGF-β pathway in reptilian sex determination.

中文翻译：

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抗苗勒管激素在睾丸分化中的作用揭示了 TGF-β 途径在爬行动物性别决定中的重要性。


抗苗勒管激素（ Amh ，或苗勒管抑制物质， Mis ）是 TGF-β 超家族的成员，已在一些脊椎动物中被充分证明是性发育的启动剂或关键调节剂，特别是在鱼类中。然而，其在爬行动物中的功能作用尚未确定。在这里，我们对中华鳖（一种表现出 ZZ/ZW 性染色体的典型爬行动物）的Amh基因进行了表征。 Amh的信使 RNA 最初在第 15 阶段（性腺性别分化之前）在雄性胚胎性腺中表达，并在整个胚胎发生过程中表现出雄性特异性表达模式。此外，在芳香酶抑制剂来曲唑诱导的雌雄逆转过程中， Amh迅速上调。最重要的是，RNA 干扰导致Amh功能丧失，导致遗传性雄性 (ZZ) 性腺完全女性化、睾丸标记Sox9受到抑制以及卵巢调节因子Cyp19a1上调。相反，ZW 胚胎中Amh的过度表达导致雌性向雄性性别逆转，其特征是睾丸结构的形成、 Sox9的异位激活以及Cyp19a1的显着下降。总的来说，这些发现提供了第一个确凿的证据，证明Amh对于驱动爬行动物物种的睾丸发育是必要且充分的， P . sinensis ，强调了 TGF-β 通路在爬行动物性别决定中的重要性。