MARBEC Univ Montpellier, CNRS, Ifremer, IRD, Palavas-Les-Flots, France.
Normandie Université, Unicaen, BOREA, 14000, Caen, France.
Fish Physiol Biochem. 2024 Dec;50(6):2423-2435. doi: 10.1007/s10695-024-01395-6. Epub 2024 Aug 28.
Primordial germ cells (PGCs) play a crucial role in sexual development in fish, with recent studies revealing their influence on sexual fate. Notably, PGC number at specific developmental stages can determine whether an individual develops as male or female. Temperature was shown to impact PGC proliferation and the subsequent phenotypic sex in some fish species. Here, we aimed at testing the role of food deprivation on gonad development in the European seabass Dicentrarchus labrax, a species displaying a polygenic sex determination system with an environmental influence. We subjected larvae to two periods of starvation to investigate whether restricting growth affects both gonadal size and vasa gene expression. We first confirmed by immunohistochemistry that Vasa was indeed a marker of PGCs in the European seabass, as in other fish species. We also showed that vasa correlated positively with fish size, confirming that it could be used as a marker of feminization. However, starvation did not show any significant effects on vasa expression nor on gonadal size. It is hypothesized that evolutionary mechanisms likely safeguard PGCs against environmental stressors to ensure reproductive success. Further research is needed to elucidate the intricate interplay between environmental cues, PGC biology, and sexual differentiation in fish.
原始生殖细胞 (PGCs) 在鱼类的性发育中起着至关重要的作用，最近的研究揭示了它们对性命运的影响。值得注意的是，特定发育阶段的 PGC 数量可以决定个体是发育为雄性还是雌性。有研究表明，温度会影响某些鱼类物种的 PGC 增殖和随后的表型性别。在这里，我们旨在测试食物剥夺对具有多基因性别决定系统和环境影响的欧洲鲈鱼 Dicentrarchus labrax 性腺发育的作用。我们让幼虫经历了两个饥饿期，以研究限制生长是否会影响性腺大小和 vasa 基因的表达。我们首先通过免疫组织化学证实，Vasa 确实是欧洲鲈鱼 PGC 的标志物，就像在其他鱼类中一样。我们还表明，vasa 与鱼类大小呈正相关，证实它可以用作雌性化的标志物。然而，饥饿对 vasa 表达或性腺大小均没有显示出任何显著影响。据推测，进化机制可能会保护 PGC 免受环境胁迫，以确保繁殖成功。需要进一步的研究来阐明鱼类中环境线索、PGC 生物学和性分化之间的复杂相互作用。
