大珠母贝外套膜表皮细胞的超微结构

利用透射电系统地观察大珠母贝的外套有皮细胞，结果表明，细胞可分为５种，即柱状表皮细胞、凸细胞、电子透明大粒细胞、电子稠密粒细胞和电子透明小粒细胞。它们在不同区域的分布、形态和数量变化与外套膜的功能分化密切相关，尤其是与贝壳组分的分泌有关。结缔组织中也分布着许多闰细胞和电子稠密粒细胞，它们可作变形运动进入表皮层。

ULTRASTRUCTURE OF EPITHELIAL CELLS OF THE MANTLE OF PINCTADA MAXIMA

Transmission electron microscope was used to observe epithelial cells of the mantle of Pinctada maxima. The results show that there are 5 Kinds of cells in the epithelium.1) The common columnar epithelial cells, which can be further divided into types A, B and C according to their ultrastructure, are involved in the secretion of different shell components. 2) Extruded cells which always extrude higher than other cells only distribute in the outer and inner fold of the marginal zone of the mantle. 3) Cells which are filled with large electron-transparent granules scatter almost everywhere of the mantle,and they can undergo ameba movement to go into the epithelium. 4) Cells which are crowded with electron-dense granules distribute in both epithelium and connective tissues, and they also undergo ameba movement to cross the epithelium in the marginal zone. 5) Cells which are filled with small electron-transparent granules only appear in the inner epithelium of the mantle.