Nucleic acid synthesis in embryos and its bearing on cell differentiation.

Animals Anura Carbon Isotopes Cell Differentiation Cell Nucleolus/metabolism Centrifugation, Density Gradient Chromatography DNA/analysis DNA Nucleotidyltransferases/metabolism DNA Replication Echinodermata Embryo, Nonmammalian/metabolism Feedback Female Fertilization Histones/metabolism Male Meiosis Nuclear Transfer Techniques Nucleic Acids/biosynthesis Ovulation Ovum/growth & development RNA/biosynthesis Ribosomes/metabolism Time Factors Tritium

Carbon Isotopes Histones Nucleic Acids Tritium RNA DNA DNA Nucleotidyltransferases