Horiguchi Ryo, Nozu Ryo, Hirai Toshiaki, Kobayashi Yasuhisa, Nakamura Masaru
Advanced Research Facilities and Services, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
Zoological Laboratory, Okinawa Churashima Research Center, Okinawa Churashima Foundation, Okinawa 905-0206, Japan.
Gen Comp Endocrinol. 2018 Feb 1;257:67-73. doi: 10.1016/j.ygcen.2017.06.017. Epub 2017 Jun 27.
The three-spot wrasse, Halichoeres trimaculatus, can change sex from female to male (i.e. protogyny) due to sharp decrease in endogenous estrogen. During the sex change, ovarian tissue degenerates and testicular tissue arises newly. Finally, ovarian tissue disappears completely and replaces into mature testis. In order to predict the molecular mechanisms controlling the processes of sex change, we investigated the expression patterns of four genes (rspo1, figla, sox9b and amh), which have been thought to be associated with ovarian/testicular differentiation in vertebrates. Expression levels of rspo1 and figla, which play important roles for ovarian differentiation in vertebrates, were stable until the middle stage of the sex change, and subsequently down-regulated. Therefore, it was indicated that decrease in rspo1 and figla could result from ovarian degeneration. On the other hand, basis on the expression pattern, it was indicated that sox9b and amh, which are involved in testicular differentiation in vertebrates, were implicated in testicular formation and spermatogenesis during the sex change as well. The present results could be fundamental information for investigating the relationship between these factors and E2 depletion, which is crucial trigger for sex change.
三斑海猪鱼（Halichoeres trimaculatus）由于内源性雌激素急剧减少，能够从雌性转变为雄性（即雌性先熟）。在性别转变过程中，卵巢组织退化，新的睾丸组织产生。最终，卵巢组织完全消失并被成熟的睾丸所取代。为了预测控制性别转变过程的分子机制，我们研究了四个基因（rspo1、figla、sox9b和amh）的表达模式，这些基因被认为与脊椎动物的卵巢/睾丸分化有关。rspo1和figla在脊椎动物卵巢分化中起重要作用，其表达水平在性别转变的中期之前保持稳定，随后下调。因此，表明rspo1和figla的减少可能是卵巢退化所致。另一方面，基于表达模式表明，参与脊椎动物睾丸分化的sox9b和amh在性别转变过程中也与睾丸形成和精子发生有关。本研究结果可能是研究这些因素与E2耗竭之间关系的基础信息，E2耗竭是性别转变的关键触发因素。
