College of Life Sciences, Northwest Normal University, Lanzhou, Gansu, China.
Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, China.
Biol Reprod. 2021 Jun 4;104(6):1194-1204. doi: 10.1093/biolre/ioab042.
As in other vertebrates, fish reproduction is tightly controlled by gonadotropin signaling. One of the most perplexing aspects of gonadotropin action on germ cell biology is the restricted expression of gonadotropin receptors in somatic cells of the gonads. Therefore, the identification of factors conveying the action of gonadotropins on germ cells is particularly important for understanding the mechanism of reproduction. Insulin-like growth factors (Igfs) are recognized as key factors in regulating reproduction by triggering a series of physiological processes in vertebrates. Recently, a novel member of Igfs called Igf3 has been identified in teleost. Different from the conventional Igf1 and Igf2 that are ubiquitously expressed in a majority of tissues, Igf3 is solely or highly expressed in the fish gonads. The role of Igf3 in mediating the action of gonadotropin through Igf type 1 receptor on several aspects of oogenesis and spermatogenesis have been demonstrated in several fish species. In this review, we will summarize existing data on Igf3. This new information obtained from Igf3 provides insight into elucidating the molecular mechanism of fish reproduction, and also highlights the importance of Igf system in mediating the action of gonadotropin signaling on animal reproduction.
与其他脊椎动物一样，鱼类的繁殖受到促性腺激素信号的严格控制。促性腺激素对生殖细胞生物学作用最令人费解的方面之一是促性腺激素受体在性腺体细胞中的受限表达。因此，鉴定将促性腺激素作用传递给生殖细胞的因素对于理解生殖机制尤为重要。胰岛素样生长因子（Igfs）被认为是通过在脊椎动物中触发一系列生理过程来调节生殖的关键因素。最近，在硬骨鱼中鉴定出了一种称为 Igf3 的 Igfs 的新成员。与普遍表达于大多数组织中的传统 Igf1 和 Igf2 不同，Igf3 仅在鱼类性腺中表达或高度表达。在几种鱼类中，已经证明 Igf3 通过 Igf 型 1 受体在卵母细胞发生和精子发生的几个方面介导促性腺激素的作用。在这篇综述中，我们将总结关于 Igf3 的现有数据。从 Igf3 获得的这些新信息为阐明鱼类繁殖的分子机制提供了线索，也强调了 Igf 系统在介导促性腺激素信号对动物繁殖的作用中的重要性。
