The role of nucleic acids in the processes of induction, regulation and differentiation in the amphibian embryo and the unicellular alga, Acetabularia mediterranea

The role of nucleic acids (DNA and RNA) during cleavage and differentiation in amphibian eggs is discussed, with special emphasis on the mechanisms of DNA synthesis in normal embryos and lethal hybrids, and on the RNA distribution during development.The importance of the cell nucleus for RNA and protein synthesis in the unicellular alga Acetabularia mediterranea is discussed on the basis of recent experiments: it is suggested that ribosomal RNA lies under a much closer nuclear control than transfer and chloroplastic RNA's.A hypothesis concerning the role of messenger and ribosomal RNA in morphogenesis is presented.