隆线溞孤雌溞生殖系统的组织学

Histology of the Female Reproductive System in Parthenogene of Daphnia (Ctendaphnia) carinata

隆线孤雌的生殖系统由一对卵巢、一对输卵管和一对雌性生殖孔组成。卵巢长管状 ,管壁由结缔组织膜和单层上皮细胞构成 ,末端渐细为一短小的输卵管 ,输卵管末端为雌性生殖孔。卵子的发生是由生发区细胞向卵巢内增殖分化 ,不同成熟度的生殖细胞在管腔内排列成生殖带。根据卵母细胞细胞核的大小及卵黄的累积情况等 ,将卵子的发生划分为三个时期 :卵原细胞、卵母细胞和成熟卵子 ,其中卵母细胞的发生又可细分为三个时期 :前期、中期和后期。后期的卵母细胞含较多的卵黄颗粒 ,最后成为成熟卵子 ,排入孵育囊内形成夏卵。隆线孤雌的卵巢发育要经历五个幼龄期 ,不同的龄期 ,卵巢的形态结构不同。至第五幼龄 ,卵巢已基本发育成熟 。

The female reproductive system of parthenogene in Daphnia (Ctendaphnia) carinata was consisted of a pair of ovaries,oviducts and female gonopores. The ovary was tube shaped and its wall was composed of connective tissue and a layer of epithelial cells. The end of ovary, which got smaller, was a female gonopore. The germinal cells at different mature levels lined in the lumen to form reproductive zone. According to the nuclear size and the vitelline accumulation, oogenesis might be divided into three stages: oogonium,oocyte and mature ovum. The genesis of oocyte also could be divided into three stages: primal,middle and final. At the final stage, the oocyte contained many globules, then developed to mature parthenogenetic ovum and finally moved to the female’s brood pouch. The ovarian development could be divided into five instars. In different instars, the morphology and structure of ovary were different. When the parthenogenetic female of D. carinata reached the fifth instar, the ovary had developed maturely and the female was ready to enter the first adult stage.