褶纹冠蚌珍珠囊发育的超微结构观察

本文报道了用透射电子显微镜对不同发育阶段褶纹冠蚌(Cristaria plicataLeach)珍珠囊的超微结构进行观察的结果。观察表明,珍珠囊上皮细胞在发育的各阶段都具有发达的微绒毛、基底迷路结构和胞间空间;线粒体、核糖核蛋白体十分丰富,高尔基体非常活跃。在发育的早期,上皮细胞及核都呈柱状,常见细胞器的自溶现象以及板层小体的形成;核糖核蛋白体大多呈游离解聚状态。在发育的晚期,上皮细胞呈立方形或扁平状,核的形状不规则;大量的、梅花状的多聚核糖核蛋白体形成。珍珠囊附近的结缔组织主要由成纤维细胞、类结缔组织钙细胞、肌纤维、胞间微纤维、无核细胞样结构和细胞碎片组成。

OBSERVATIONS ON THE ULTRASTRUCTURE OF DEVELDPING PEARL SACS OF CRISTARIA PLICATA LEACH

The ultrastructure of pearl sacs of Cristaria plicata Leach in dif-ferent developmental stages were observed under electronic microscope. The epi-thelial cells of pearl sac have abundant microvilli in their apical surfaces, well-de-veloped basal membrane-invaginated system and intercellular spaces (latteral)and there are a lot of mitochondria, ribosomes and Golgi bodies in the cytoplasm.During the early development, the epithelial cells and their nuclei are columnar,some nucleus division can be seen,lysosomes are strongly active, lysis of cellularorganelies occur usually, and many lamellar bodies form; most of the ribosomes areisolated granules scattered in the cytoplasm. During the latter development, howe-ver, the epithelial cells become cuboid or squamous, the form of the nuclei are irre-gular; lysosomes and the basal membrane-invaginated system are less than thosein the early period, but the inteacellular spaces become extremely noticeable.Rough endoplasmic reticulum increrses in number and almost all of the ribosomes.accumulate as rosette configurations called polysomes. The connective tissue adja-cent to the epithelium consists of ceils, including fibroblasts and quasi-connective-tissue-calcium (QCTC) cells and myocytes, inter-cellular microfilaments, cell-likestructures and cell pieces. There are more fibroblasts in the early period, more intercellular microfilaments and cell pieces and cell-like structures occur in thelatter period.