鱼类性腺发育研究进展

A Review of Research Progress on Gonadal Development in Fish

性腺发育对鱼类的成功繁殖与种群延续至关重要。鱼类的性腺发育包括原始性腺的形成和分化、性腺的组织结构、形态特征与时相划分以及环境因素对性腺发育的影响等。掌握鱼类原始生殖细胞(Primordial germ cells, PGCs)的起源、迁移和分化特征是研究性腺发育规律的基础。鱼类的PGCs出现于胚胎发育早期,以不同方式迁移到生殖嵴,与生殖上皮共同形成原始性腺,之后向精巢或卵巢分化。鱼类性别决定和性分化呈多元性,既有雌雄同体也有雌雄异体。遗传和环境因素(如温度、光照、激素和pH等)影响性腺的性别分化,具有可逆可塑性。判断鱼类性腺分化方向依据两方面:一是观察性腺的组织学形态特征变化;二是以性原细胞的出现及其减数分裂的细胞学分化。性腺分化主要包括雌雄异体、雌雄同体和性逆转三种类型;雌雄异体型又分为分化型和未分化型。本文通过综述鱼类原始生殖细胞的起源、迁移和分化、性别分化以及性腺发育的研究进展,以期为鱼类性腺发育的研究提供参考。

Gonadal development plays a key role in breeding of fish, especially prolongation of the population. Research of fish gonadal development mainly includes the formation and differentiation of primordial gonads, structures of testis and ovary, morphological characteristics and stage division of gonadal development, and the influence of environmental factors on gonadal development. The origin,migration and differentiation of fish primordial germ cells(PGCs) are the basis for understanding of gonadal development. The PGCs of fish appear at the early stage of embryo development, migrate to genital ridge in different ways, form the primordial gonad with reproductive epithelium, and then differentiate into testis or ovary. The diverse sex determination and sexual differentiation, which is influenced by genetic and environmental factors(such as temperature, light, hormone and pH and has reversible plasticity, of fish are comprised of hermaphrodite and dioecious. The markers of gonadal differentiation in fish are manifested in two approaches: differentiation of histology is based on the external morphology of the gonads, and differentiation of cytology is depended on the appearance of oogonium and spermatogonium and initiation of meiosis. There are three types of gonadal differentiation, androgyny, hermaphroditism(differentiated and undifferentiated types) and sex reversal. The origin, migration, differentiation of PGCs, sex determination, sexual differentiation, and gonadal development in fish are reviewed in this paper, aiming to provide references for the research of fish gonadal development.