【摘要】 用透射电镜和扫描电镜观察隆线精子的发生过程及成熟精子的超微结构。隆线精子发生经历精原细胞、精母细胞、精子细胞和成熟精子四个时期。精原细胞核染色质凝集成团,细胞质内有线粒体、粗面内质网分布。精母细胞核染色质分散,不均匀地分布于核中,细胞质内粗面内质网聚集。在精子细胞分化形成精子的早期,细胞纵向拉伸,核物质开始浓缩;中期精子细胞呈明显的长条形,精子细胞逐渐移入精巢管腔中央,外围包裹一厚层精子鞘;后期精子细胞已进入管腔中,核物质呈高度浓缩状,细胞质层较少,精子细胞间通过外围精子鞘相互粘连成片。成熟精子分散在精巢管腔中央,外形呈棒状,一端稍钝,一端稍尖,无鞭毛、棘突等附属物;核内染色质解聚,均匀分布在核中,具双层核膜,细胞质层很少,精子鞘为单层,无法确认顶体端。隆线雄性生殖细胞的结构及其发生过程均较高等甲壳动物简单和原始,但在功能上表现出相对的适应性,使以隆线为代表的枝角类能适应复杂多变的生活环境更多还原

【Abstract】 The spermatogenesis and fine structure of spermatozoon in the Daphnia (Ctenodaphnia) carinata were examined with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Spermatogenesis can be divided into four stages: spermatogonium, spermatocyte, spermatid and spermatozoon. Spermatogonia were found in the testicular tubule of the newborn male. Spermatogonia were oval or polygonal shape and each contained a large oval nuclear with dense chromatin in the center. In the relatively transparent cytoplasm of spermatogonium, there were some oval mitochondria with clear cristae and rough endoplasmic reticulum. The spermatocyte was smaller than the spermatogonium and became polygonal in shape. The chromatin dispersed irregularly in the nucleus. The rough endoplasmic reticulum assembled together in the cytoplasm. The spermatid was elongated longitudinally and the chromatin began condensation and the rough endoplasmic reticulum still appeared in clustering. The spermatid developed into the spermatozoon through three stages. In the first stage, the spermatid gradually stretched out longitudinally, and the chromatin condensed into two or more blocks. The layer of cytoplasm became thinner, and there were still some mitochondria and rough endoplasmic reticulum in it. In the second stage, the striped spermatid began moving to the tubular lumen of testis and was wrapped by the sperm scabbard. The chromatin condensed and the cytoplasm reduced to a thin layer lacking of organelles. In the third stage, most of the spermatids moved into the tubular lumen of testis and were connected to each other by the sperm scabbard which was composed of multilayer membranes. The chromatin became more condensed. The ripe sperms dispersed into the tubular lumen of the testis and the sperm scabbard changed into a thin layer which wrapped the sperm tightly. The chromatin were dispersed and distributed evenly in the nucleus, and the double-karyothecas remained distinct. But we couldn’t ascertain the acrosome and other correlative structures in the ripe sperm. SEM observation showed the spermatozoon had a clavated body, one end of it was blunt, and the other was cuspate. The exterior of the sperm was smooth and had neither radial arms nor spikes. The structure and genesis of the male reproductive cells in the Daphnia (Ctenodaphnia) carinata were very simple and retained primitive characters compared with advanced crustacea, while they appeared some functional adaptability which enabled Daphnia (Ctenodaphnia) carinata and other species of Cladocera to live in various environments .更多还原