中华绒螯蟹卵巢和胚胎发育期脂类在卵黄物质中存在的形态及其变化

Abstract

脂类在中华绒螯蟹成熟卵子中以两种形态存在：脂肪滴（l）和卵黄体（y），前者为中性脂，卵黄体中的脂类主要是磷脂。l和y几乎充满整个成熟卵子，且交互分布，开始它们间以许多致密小颗粒（Sg）间隔，直到两者的分布无界限分割。l和y的形态也各有变化。l和y的分布和变化可以作为卵子成熟度的标志。胚胎发育期l和y的分布发生了显著的变化，两者呈网状分布，l近圆形，为网状卵黄物质的网眼。在胚胎发育过程中，与卵黄物质相邻接的是合胞体，并以此来吸收l和y。卵巢快速发育时期，是卵黄发生旺期，卵是以y的积极合成为特征的，象成熟卵子和胚胎发育卵中的特征性的l极为少见。

Histochemistry result indicates that neutral lipid of the yolk materials is mainly present as lipid droplets, and phospholipid is mainly contained in the yolk bodies. In the stage of ovarian fast development, most oocytes are characterized by active yolk body (Y) synthesis, only a little lipid droplets(L) accumulation can be seen in those oocytes. In contrast with the development oocytes, the large amount of lipid droplets are present in mature ooytes of Eriocheir sinensis. L and Y are distributed alternately and occupied almost cytoplasm of oocytes.There are some variation in the shape of L and Y which may represent the different degrees of mature oocytes. Significantly ultrastructure changes on Y and L distribution was observed in the mature oocytes and embryonic eggs.Y and L form in net like structure in all embryonic stages, this type of distribution may be suitable for the use of yolk materials.Yolk materials was absorbed by combined cells which may be responsible for the rapid embryonic development.