日本沼虾卵巢发育的组织学与组织化学观察

Histological and histochemical observation on ovary development in oriental river prawn Macrobrachium nipponense

应用组织切片、组织化学技术,对日本沼虾雌性生殖系统的组织结构、卵巢发育周期进行研究。结果表明,日本沼虾雌性生殖系统由卵巢和输卵管组成,卵巢外被结缔组织膜与生殖上皮。日本沼虾的卵巢发育具有明显的色泽与体积的变化,根据其外部形态和内部结构,将其划分为增殖期、小生长期、大生长期、成熟期和恢复期5个时期。卵子发生可分为卵原细胞期、卵黄发生前期、卵黄发生期、卵黄发生后期4个时期。卵黄发生前期的卵母细胞为小生长期的初级卵母细胞,胞质嗜碱性,无卵黄颗粒;卵黄发生期卵母细胞为大生长期卵母细胞,胞质嗜酸性,早期含卵黄颗粒,后期转变为卵黄块,核位于卵母细胞中央;卵黄发生后期卵母细胞为成熟期卵母细胞,体积长足,核移动到卵母细胞周边,最终核生发泡破裂,核膜消失,卵周围滤泡细胞层变得极薄,等待排卵。

In the study, histologic section and histochemical methods were used to research the organizational structure of female reproductive system and ovary development cycle in oriental river prawn Macrobrachium nipponense. The results show that the female reproductive system is composed of ovary and oviduct, and the ovary is covered with connective tissue capsule and reproductive epithelium. The ovarian development of oriental river prawn has significant changes in color and volume, therefore, according to the external shape and internal structure, ovarian development can be divided into five stages, including multiplication stage, minor growth stage, major growth stage, maturation stage and recovery stage. Oogenesis can be divided into four stages： oogonium stage, previtellogenesis stage, vitellogenesis stage, late vitellogenesis stage. The previtellogenesis oocytes is regarded as niche long-term primary oocyte, the cytoplasmic is filled with basophilic cells and no yolk granules. The vitellogenesis oocytes is the huge growing oocytes, the cytoplasmic is filled with eosinohilic cells, the early vitellogenesis oocytes contains yolk granules and blocks late into yolk, the nucleus is located in the central of oocytes. The period of the oocytes has been mature with great volume in the late vitellogenesis stage, nuclear moves to the surrounding of the oocyte, eventually the germinal vesicle breakdowns and the nuclear membrane disappeares, the egg around follicular cell layer becomes extremely thin, waiting for ovulation.