MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Jiangsu Province, 210095, China; Faculty of Veterinary and Animal Sciences, University of Poonch Rawalakot, Azad Kashmir, Pakistan.
MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Jiangsu Province, 210095, China.
Micron. 2019 Jun;121:84-89. doi: 10.1016/j.micron.2019.03.006. Epub 2019 Apr 1.
Autophagy is a subcellular process that is extensively involved in spermiogenesis. In this study, we observed ultrastructural malformation of acrosome and mitochondrial cristae during the spermiogenesis of Chinese soft-shelled turtle due to the inhibition of autophagy. Autophagy was blocked with 3-MA, and the inhibition of autophagy was confirmed through western blot analysis. The morphological abnormalities of acrosomes and mitochondria were observed under transmission electron microscopy (TEM). In the early spermiogenesis (Golgi and cap phases), damaged macrovesicle was observed, and its proper expansion over the nucleus failed to be form a normal acrosomal cap. As spermiogenesis proceeded, the malformation of the acrosome in spermatids became more severe. In the late spermiogenesis (acrosomal and maturation phases), defective acrosome with damaged acrosomal membrane that was detached from the nucleus was observed. Along with malformed acrosome, elongation failed nucleus having oval or round shaped morphology was also observed. Moreover, morphological damage to the mitochondrial cristae was observed. Lacuna formation, half and complete loss of cristae were observed in the mitochondria of developing spermatids. We proposed that autophagy is required for normal formation of the acrosome and mitochondrial cristae during turtle spermiogenesis.
自噬是一种广泛参与精子发生的细胞内过程。在这项研究中，我们观察到由于自噬被抑制，中华鳖精子发生过程中顶体和线粒体嵴的超微结构畸形。使用 3-MA 阻断自噬，并通过 Western blot 分析确认自噬被抑制。在透射电子显微镜（TEM）下观察顶体和线粒体的形态异常。在早期精子发生（高尔基体和帽状期）中，观察到受损的大囊泡，其未能正常覆盖在核上，导致顶体帽的正常扩张失败。随着精子发生的进行，精子头部的畸形变得更加严重。在晚期精子发生（顶体和成熟阶段）中，观察到顶体膜受损的畸形顶体与核分离。伴随着畸形的顶体，也观察到伸长失败的核呈现椭圆形或圆形形态。此外，还观察到线粒体嵴的形态损伤。在发育中的精母细胞的线粒体中观察到腔隙形成、嵴的一半和完全缺失。我们提出自噬对于龟类精子发生中顶体和线粒体嵴的正常形成是必需的。
