Abstract：
Some teleost fishes change their sex, and some of these fishes have specific gonads known as \"ovotestes,\" that is, gonads containing both ovarian and testicular tissues. In this study, we revealed the gonadal transformation process and cell dynamics during the female-to-male sex change in the harlequin sandsmelt, Parapercis pulchella (Pinguipetidae), in which females possess ovotestes. Histological observations revealed that although female ovotestes were composed of oocytes, a few cysts of male germ cells were observed among them. At the initial phase of sex change, male germ cells increased, and spermatogenesis proceeded. After that, oocytes decreased and finally disappeared, and the gonads became functional testes. Immunohistochemistry using antibodies against Pcna (proliferating cell nuclear antigen) as a cell proliferation marker revealed that spermatogonia were Pcna positive, whereas spermatocytes were negative, in female ovotestes. This suggests that spermatogenesis is arrested at the spermatocyte stage. In addition, some somatic cells surrounding oocytes, which were thought to be the female follicle cells, were Pcna positive during sex change, indicating that these cells proliferate during sex change and are reused in male testes after sex change. Also, immunostaining using antibodies against active cleaved-Caspase3a as an apoptosis marker demonstrated that oocytes degenerated through apoptotic cell death at the late transition stage. Together with previous findings in other fishes, these findings suggested that the histological processes in gonads during sex change, such as the order of developmental events, developmental fates of ovarian cavities, and ovotestis structures, are diversified among fish species. In contrast, cellular dynamics of female germ and somatic cells during sex change are common among protogynous species.
摘要：
一些硬骨鱼改变了他们的性别，其中一些鱼类有特殊的性腺，称为“ovotestes”，即，含有卵巢和睾丸组织的性腺。在这项研究中,我们揭示了在丑角solsmelt中女性到男性性别变化过程中的性腺转化过程和细胞动力学，Parapercispulchella（Pinguipetidae），雌性拥有卵细胞。组织学观察显示,尽管雌性卵细胞由卵母细胞组成，其中观察到一些雄性生殖细胞囊肿。在性别改变的初始阶段，男性生殖细胞增加，精子发生进行。之后,卵母细胞减少，最后消失，性腺变成了功能性睾丸.使用针对Pcna（增殖细胞核抗原）的抗体作为细胞增殖标记的免疫组织化学显示精原细胞Pcna阳性，而精母细胞是阴性的，在女性Ovotestes中。这表明精子发生在精母细胞阶段被阻止。此外,一些围绕卵母细胞的体细胞，被认为是女性卵泡细胞，Pcna在性别变化时呈阳性，表明这些细胞在性别变化过程中增殖，并在性别变化后在男性睾丸中重复使用。此外，使用针对活性裂解的Caspase3a的抗体作为凋亡标志物的免疫染色表明，卵母细胞在后期过渡阶段通过凋亡细胞死亡而变性。加上以前在其他鱼类中的发现，这些发现表明性腺在性别变化过程中的组织学过程，比如发展事件的顺序，卵巢腔的发育命运，和卵睾丸结构，鱼类种类多样化。相比之下,雌性生殖细胞和体细胞在性别变化过程中的细胞动力学在原种中很常见。本文受版权保护。保留所有权利。
