ABSTRACT
Technological advances have made possible studies of regulation of specific genes, including single-copy genes. Recombinant Deoxyribonucleic acid (DNA) technology has provided means to identify and amplify any gene for which an appropriate probe is available. In most cases, histones are synthesized only during the S phase of the cell cycle, and histone messenger RNAs appear on polysomes only during periods of DNA replication. E. D. Adamson and H. R. Woodland found that histones were synthesized during Xenopus oogenesis and in enucleated oocytes; in both cases, no DNA synthesis occurs. In order to verify the apparent coordination of DNA and histone synthesis, it was essential to identify histones unequivocally among the acid-soluble nuclear proteins, and to examine incorporation of into histones at different stages of development. Acid-soluble proteins extracted from Artemia nuclei were fractionated by the method of E. W. Johns and analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate.
