早期小白鼠胚的核酸和糖元

NUCLEIC ACIDS AND GLYCOGEN IN THE EARLY DEVELOPMENT OF MOUSE EMBRYOS

序言核酸的機能問題目前仍未完全解决,從化學分析和組織化學方面所積累的材料推断,核酸的代謝和蛋白質合成之間存在着密切的關係。Caspersson[1]首先發現迅速生長的組織細胞裏具有高濃度核糖核酸的特徵。

Mouse embryos 1-9 days of Vaginal plug age were used for the study of the distribution of nucleic acids and glycogen by the methyl green-pyronine and the periodic acid Schiff’s(PAS)methods respectively.During the pronucleus and cleavage stages only traces of ribonucleic acid were present in the cytoplasm.The small amount of desoxyribonucleic acid,present during pronucleus stage,increased gradually and reached the normal level at 4-16 cell stage.Desoxyribonucleic acid was not found in the cytoplasm.The ribonucleic acid in the cytoplasm began to increase from the stage of early blastocyst and became conspicuous at the time of impl-antation.After the ectoderm and entoderm had differentiated,ribonucleic acid was found to be most abundant in the embryonic ectoderm,the early amnionic fold and the primitive streak,while the extraembryonic ectoderm and the ectoplacental cone contained less and the entoderm the least.In neurula large amount of ribonucleic acid was found in the nervous system.During the pronucleus stage the cytoplasm was found to be weekly PAS positive.During cleavage and early blastocyst stages glycogen was present in moderate amount and zona pellucida was PAS positive.In the initial stage of implantation,before the placenta had well deye-loped,glycogen disappeared almost completely in the embryo,but large amount of glycogen granules was present in the superficial layer of the decidua surrounding the embryo.During the amnionic and the primitive streak stages,glycogen granules appeared in the ectoplacental cone and the extra-embryonic ectoderm.The Reichert’s membrane and the distal borders of the entodermal cells showed strong PAS positive reactions.In the 9-day embryo large amount of glycogen was present in the heart.Allantois,head mesoderm and the epithelia of the newly formed hind gut contained small amount of glycogen granules.PAS positive material was found in the cavity of the fore gut.