双酚A对鱼类精子发生的危害及其分子机制研究

Bisphenol A (BPA) is an endocrine disturbing compound (EDC) ubiquitously distributed in aquatic environment. It was highly accumulated in wild fish and has detrimental effects on reproduction of male fish. However, the mechanism is not clear. In the preliminary experiment of BPA exposure on rare minnow Gibiocypris rarus, our valuable results suggest that BPA affect spermatogenisis at several levels in fish. In the present study, G. rarus and zebrafish Danio rerio will be exposed to BPA for for short and long duration. The sperm quality will be detected and ultrastructure of spermid and spermatozoa will be observed. Investigations will be performed using techniques of molecular biology, biochemistry and immunohistochemistry to explore the potentail mechanisms underlying the detrimental effects on spermatogenesis upon BPA exposure. The investigations include analysis of disturbed cytokine expression elicited by oxidative stress affecting function of blood-testis barrier upon BPA exposure, assay on apoptosis of spermatogenic cells as the permeability of blood-testis barrier is altered by BPA exposure, and study on BPA’s effects on cytoplasmic removal of spermid during spermiation. The present findings will clarify the negative effects on reproduction and fertility of male fish upon BPA in aquatic environment and will provide theoretical basis for the negative effects on wild fish population and its ecological protection under exposure of various ubiquitous phenolic endocrine disturbing compounds.

双酚A（BPA）是水环境中广泛分布的内分泌干扰物，它在鱼类体内有较高的富集，显著危害雄鱼的生殖，但其机制还不清楚；我们在稀有鮈鲫BPA暴露的预实验中获得了部分有价值的结果，提示BPA在多个方面影响鱼类精子发生。本项目拟以稀有鮈鲫和斑马鱼为实验鱼，经BPA短期和长期暴露后，观察它们的精子细胞和精子的亚显微结构变化，并检测成熟精子的质量，然后采用分子生物学、生化和免疫组化方法从多个方面探讨这些危害效应的可能发生机制，包括BPA引发氧化胁迫后干扰细胞因子的表达最终对血睾屏障通透性和功能的影响， BPA对生精细胞凋亡的影响，及BPA对排精过程中精子细胞内胞浆消除的影响。本项目的成果将有助于阐明水环境中BPA影响雄性鱼类生殖能力的分子机制，为水环境中普遍存在的各种酚类内分泌干扰物对鱼类种群的影响及其生态保护提供理论支持。