Methyltestosterone efficiently induces male development in the self-fertilizing hermaphrodite fish, Kryptolebias marmoratus
Methyltestosterone efficiently induces male development in the self-fertilizing hermaphrodite fish, Kryptolebias marmoratus
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DOI：
10.1002/dvg.20240
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发表时间：
2006-10-01
期刊：
影响因子：
1.5
通讯作者：
Hori, Hiroshi
中科院分区：
文献类型：
--
作者：
Kanamori, Akira;Yamamura, Aki;Hori, Hiroshi
雌雄同体的鱼（Kryptolebias marmoratus）是唯一已知的通过自体受精繁殖的脊椎动物。在自然界中，很少观察到雄性。众所周知，胚胎晚期的低温处理可以诱导雄性，但其效果却存在差异。在这里，我们报告说，对胚胎进行 17 α-甲基睾酮 (MT) 处理后，大多数鱼变成了雄性。我们通过组织学和标记基因表达分析检查了这种雄性诱导的时间过程。卵子发生在孵化时对照胚胎的性腺中开始；精子发生直到孵化后两个月才开始。在经过 MT 处理的鱼中，卵子发生最初与对照组一样开始，但在孵化后一个月内完全停止。相反，精原细胞增殖比对照鱼更早开始，并进展到完全精子发生。性别特异性标记基因的表达谱与组织学观察结果吻合良好。从孵化后一个月开始，对照鱼和 MT 处理鱼的卵母细胞特异性标记物 Fig alpha 和睾丸体细胞标记物 dmrt1 的表达分别开始增加。
A hermaphrodite fish, Kryptolebias marmoratus, is the only known vertebrate that reproduces by self-fertilization. In nature, males have been rarely observed. Low-temperature treatment during late embryonic stages is known to induce males but its efficacy is variable. Here we report that 17 alpha-methyltestosterone (MT) treatment of the embryos converted most of the fish to males. We examined a time course of this male induction with histological and marker gene expression analyses. Oogenesis started in the gonads of the control embryo at hatching; spermatogenesis did not start until two months after hatching. In the MT-treated fish, oogenesis started initially as in the control but stopped completely within one month after hatching. Instead, spermatogonial proliferation started earlier than in the control fish and progressed to full spermatogenesis. Expression profiles of the sex-specific marker genes corresponded well with histological observations. From one month after hatching, expression of an oocyte-specific marker, fig alpha, and a testicular somatic cell marker, dmrt1, started to increase in the control and in the MT-treated fish, respectively.