中华绒螯蟹Y-器官在蜕皮周期中的超微结构

以光镜和电镜观察处于蜕皮周期不同阶段的中华绒螯蟹(Eriocheirsinensis),结果显示,中华绒螯蟹具Y-器官(YO)1对,卵圆形,直径1 5～2 0mm,苍黄色,位于头胸部鳃腔前端,大颚外侧内收肌腹缘,邻近头胸甲内侧上皮。YO细胞排列成索状,细胞索之间为血窦,YO的细胞索由一种细胞构成,细胞核质比高。YO细胞具有类似脊椎动物合成类固醇激素的典型超微结构特征,蜕皮前期YO细胞的光面内质网、管嵴状线粒体和游离核糖体丰富;蜕皮后期和蜕皮间期的内质网、线粒体和游离核糖体明显减少;青春蜕皮后的YO出现大面积细胞凋亡,YO趋向退化。

Ultrastructure of Y-organ in Eriocheir sinensis during molt cycle

The Chinese crab, Eriocheir sinensis, was observed at different stage during its molt period. The results show that E.sinensis has one pair of Y-organs (YO), ovoid in shape, 1.5 to 2 mm in diameter, light milky yellow in color, lying under the ventral edge of the external adductor muscle of mandible, near the inner epithelium of cephalothracic carapace. The YO consists of anastomosing cords of cells separated by numerous hemocoelic sinuses. The cell cords of YO are composed of one kind of cell with a high nucloplasma ratio and the YO cells are possessed of the typical ultrastructural features of the steroid synthesis which is similar to the vertebrates. During premolt stage the YO cells show abundant smooth endoplasmic reticulum, mitochondria with tubular cristae and numerous free ribosomes, and these organelles arereduced significantly in number during the postmolt and the intermolt stages; the YO cells tend to degenerate after the post of pubertal molt.