Effect of Postponement of Insemination in Frog Eggs Kept in vitro on the Development of Germinal Plasm and Primordial Germ Cells

概要

論文の詳細を見る
The movement of germinal plasm and the formation of primordial germ cells (PGCs) were examined in embryos after the delayed in vitro insemination of frog eggs of Rana nigromaculata and R. brevipoda. In normal embryos at the mid-blastula stage, most of the germinal plasm was found in the upper macromeres. In embryos after delayed insemination at same stage, on the other hand, a few islets consited of only a little germinal plasm were located in the upper macromeres and other germinal plasm was found in the middle and lower macromeres. The amount of germinal plasm in the lower position tended to increase as the delay in insemination was lengthened. The total number of PGCs in stage-I larvae raised from 24- or 48-hr delayed eggs was not much different from that in the control larvae at the same stage. However, PGCs in the former were mostly small and often granular cells with a round and strongly stained uncleus, differing from the large cells with a lobed and weakly stained uncleus. An unususal formation of PGCs in larvae derived from overripened eggs may cause an upset of the initial migration of germinal plasm as observed in UV-irradiated eggs.
社団法人日本動物学会の論文
1982-03-25