Toyama Y, Iwamoto T, Yajima M, Baba K, Yuasa S
Department of Anatomy and Developmental Biology, School of Medicine, Chiba University, Chiba, Japan.
Int J Androl. 2000 Apr;23(2):109-15. doi: 10.1046/j.1365-2605.2000.t01-1-00217.x.
The ultrastructure of decapitated tails and decaudated heads of ejaculated spermatozoa from an infertile man were investigated. The decaudated heads had the nucleus and acrosome, but neither the implantation fossa nor the basal plate were observed at the caudal pole of the nucleus. The nuclear membrane at this portion showed numerous nuclear pores. The decapitated tails contained the proximal centriole at the proximal end. In addition, most decapitated tails had segmented columns, outer coarse fibres, axoneme, mitochondrial sheath and fibrous sheath in the normal position. The ultrastructure reflects the high motility of the decapitated tails of the spermatozoa. Drastic abnormalities were found in the developing spermatids in the biopsied testes. In spermatids later than the Golgi phase, the pair of centrioles were floating in the cytoplasm of the spermatid, but the distal centriole elongated the flagellum. Neither the implantation fossa nor the basal plate were observed at the caudal pole of the nucleus. It is concluded that the tail might be separated from the head before or after completion of tail formation in spermatids. The explanation for why the proximal centriole failed to connect to the nucleus is unknown.
对一名不育男性射出精子的断头尾和去尾头的超微结构进行了研究。去尾头有细胞核和顶体，但在细胞核的尾极未观察到植入窝和基板。该部分的核膜显示有许多核孔。断头尾在近端含有近端中心粒。此外，大多数断头尾在正常位置有节段柱、外粗纤维、轴丝、线粒体鞘和纤维鞘。超微结构反映了精子断头尾的高运动性。在活检睾丸的发育中的精子细胞中发现了严重异常。在高尔基体期之后的精子细胞中，一对中心粒漂浮在精子细胞的细胞质中，但远端中心粒延长了鞭毛。在细胞核的尾极未观察到植入窝和基板。得出的结论是，尾巴可能在精子细胞尾巴形成完成之前或之后与头部分离。近端中心粒未能与细胞核连接的原因尚不清楚。
