Zhang Yingying, Cheng Mengqian, Wu Lang, Zhang Guo, Wang Zaizhao
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100 China.
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100 China.
Aquat Toxicol. 2016 Oct;179:18-26. doi: 10.1016/j.aquatox.2016.08.013. Epub 2016 Aug 20.
Bisphenol A (BPA) is an endocrine disruptor, and could induce germ cells apoptosis in the testis of mammals. But whether it could affect fish in the same mechanism has not' been studied till now. In the present study, to investigate the influence of BPA on testis germ cells in fish, adult male rare minnow Gobiocypris rarus were exposed to 225μgL(-1) (0.99μM) BPA for 1, 3 and 9 weeks. Through TdT-mediated dUTP nick end labeling (TUNEL) and transmission electron microscope (TEM) analysis, we found that the amount of apoptotic spermatocytes significantly increased in a time dependent manner following BPA exposure. Western Blot results showed that the ratio of Bcl2/Bax, the important apoptosis regulators in intrinsic mitochondrial apoptotic pathway, was significantly decreased. qPCR showed that mRNA expression of several genes in mitochondrial apoptotic pathway including bcl2, bax, casp9, cytc and mcl1b were significantly changed following BPA exposure. In addition, mRNA expression of meiosis regulation genes (kpna7 and wee2), and genes involved in both apoptosis and meiosis (birc5, ccna1, and gsa1a) were also affected by BPA. Taken together, the present study demonstrated that BPA could induce spermatocytes apoptosis in rare minnow testis, and the apoptosis was probably under regulation of intrinsic mitochondrial apoptotic pathway. Moreover, the spermatocyte apoptosis was likely initiated by BPA induced meiosis arrest.
双酚A（BPA）是一种内分泌干扰物，可诱导哺乳动物睾丸中的生殖细胞凋亡。但它是否能以相同机制影响鱼类，目前尚未见相关研究报道。在本研究中，为了探究双酚A对鱼类睾丸生殖细胞的影响，将成年雄性稀有鮈鲫（Gobiocypris rarus）暴露于225μg/L（0.99μM）的双酚A中1、3和9周。通过TdT介导的dUTP缺口末端标记法（TUNEL）和透射电子显微镜（TEM）分析，我们发现双酚A暴露后，凋亡精母细胞数量呈时间依赖性显著增加。蛋白质免疫印迹结果显示，线粒体凋亡内源性途径中的重要凋亡调节因子Bcl2/Bax的比值显著降低。定量聚合酶链反应（qPCR）结果表明，双酚A暴露后，线粒体凋亡途径中包括bcl2、bax、casp9、cytc和mcl1b在内的几个基因的mRNA表达均发生了显著变化。此外，减数分裂调控基因（kpna7和wee2）以及参与凋亡和减数分裂的基因（birc5、ccna1和gsa1a）的mRNA表达也受到了双酚A的影响。综上所述，本研究表明双酚A可诱导稀有鮈鲫睾丸中的精母细胞凋亡，且该凋亡可能受线粒体凋亡内源性途径的调控。此外，精母细胞凋亡可能是由双酚A诱导的减数分裂阻滞引发的。
