カブトガニの内卵膜形成について

概要

論文の詳細を見る
The inner egg-membrane formation in the extra-embryonic area of T.tridentatus eggs was studied light- and electron-microscopically. The membrane consists of an outer thin layer of high electron density and an inner thick one of low electron density. Both layers are produced by the blastoderm cells during about 7 days from Stage 11 to 14. During the first 3 days, the cells grow towards the outside, with the increase of the endoplasmic reticulum and fine secretory granules originating from the Golgi complexes. As the growin g cells retain their contact with each other only at the basal half, the outer free surface of the blastoderm assumes a folded pattern. The outer layer is gradually deposited, by the release of the secretory granules, on the blastoderm surface following the folded pattern. In the subsequent 4 days, the inner layer is rapidly deposited between the outer layer and the blastoderm surface returning to the flat pattern by the involution of the cells with rapid release of the secretory granules. Then, the membrane thus formed is separated from the flat surface of the blastoderm and expands remarkably, during the embryonic development, by the uptake of sea water into the perivitelline space. This expansion seems to be made possible by the unfolding of the outer layer and the extension of the inner one.
社団法人日本動物学会の論文
1976-03-25