红树蚬精巢发育的组织学研究和精子超微结构的观察

Histological study of spermary development and ultrastructural observation of sperm from Polymesoda erosa

采集了雄性红树蚬精巢组织样本,采用组织切片法对精巢发育进行了组织学观察,并利用透射电镜研究了红树蚬精子的超微结构.结果显示,雄性红树蚬精巢具有滤泡型的典型特点,由大量分枝的生殖管构成生精小管,生精小管末端膨大为滤泡,滤泡由滤泡壁和滤泡腔组成,不同发育阶段的生精细胞在腔内成层排列,精原细胞和精母细胞靠近滤泡壁,腔内为精细胞和成熟精子.雄性红树蚬性腺发育过程经历5个时期,分别为增殖期、生长期、成熟期、排放期和休止期.成熟精子由头部、中段和尾部组成.头部长约6μm,宽约1μm,呈锥形,由顶体和精核组成,顶体呈倒"V"字形,内含物的电子密度低于精核,精核内可观测到泡状结构;中段包含4个线粒体及其围绕着的近、远端中心粒,线粒体呈球形,可见双层膜结构;尾部为细长鞭毛,宽约0.4μm,具典型的"9+2"微管结构.

Histological section technique and electron microscopy were applied to study the development and ultrastructure of Polymesoda erosa Solander spermary.The results showed that the spermary of P.erosa has a typical follicular pattern.Seminiferous tubules are highly branched with the ends being expanded into follicles.The follicles are composed of follicular wall and cavity.Spermatogenic cells are arranged in layers by developmental stages in the cavity,with spermatogonia and spermatocyte being near the follicular wall,and spermatocytes and mature sperm being in the cavity.The gonad development process can be divided into 5 stages:proliferating stage,growth stage,ripening stage,spawning stage and resting stage.Mature sperm is composed of head,middle segment and tail.The head is conical shaped,about 6μm long and 1μm wide,which consists of inverted"V"shaped acrosome and sperm nucleus.Electron density of the inclusion is lower than that of sperm nucleus,with observable vesicular structure within the sperm nucleus.Middle segment comprises 4 mitochondria,and proximal and distalis centrioles that orbiting around the former.Mitochondria are spherical and consist of double-layered membrane.The flagell is elongated,approximate 0.4μm wide,with a typical"9+2"microtubule structure.