Pattern of RNA synthesis in isolated cells of Xenopus laevis embryos

Abstract

It has been shown that in isolated cells obtained from Xenopus laevis embryos, uridine- 3H, thymidine- 3H, and 14C-labeled protein hydrolyzate are incorporated very rapidly into acid-insoluble materials. The extent of incorporation is strikingly greater than that into intact embryos. The uridine- 3H incorporation is sensitive to actinomycin D at a concentration as low as 0.5 μg/ml. These isolated cells derived from blastulae have been shown to synthesize soluble and ribosomal RNA in an orderly succession, as do intact embryos. The synthesis of soluble RNA is followed by that of ribosomal RNA, the latter being initiated only after incubation for a certain period. During this period, the intact embryos reach the gastrula stage and begin ribosomal RNA synthesis. The synthesis of ribosomal RNA in the isolated cells is then activated very rapidly. It has been suggested on the basis of the results obtained that the isolated cells can be used for biochemical investigations.