The induction of DNA synthesis by frog egg cytoplasm

摘要: Abstract The early effects are described of injecting nuclei from embryonic, larval, and adult cells Xenopus laevis into unfertilized eggs the same species. 3 H-thymidine was injected immediately, or at intervals, after injection nuclei. Autoradiography sectioned showed whether had synthesized DNA exposure to egg cytoplasm. great majority gastrula endoderm cells, as well liver, brain, blood some time during 90 minutes following eggs. In case cell this constitutes a very considerable change in function, since not more than 1% these incorporate 90-minute period vivo , procedure used prepare did itself induce synthesis. This nuclear function is induced by exposing normal cytoplasmic influence Class specific over 90% mouse liver also synthesize frogs' Gastrula, commence synthesis later, continue it for longer, nucleus fertilized egg. observed transplanted embryonic which were destined promote abnormal development. Liver, swell up 60 times eggs, increase volume takes place rate that DNA. These enter mitosis immediately