Histone mRNA in Xenopus laevis ovaries: identification of the H4 messenger

RNA extracted from ovaries of adult Xenopus laevis and introduced into a wheat germ cell-free system, directs the synthesis of polypeptides co-electrophoresing with all five histones. By frationation of total ovary RNA through Sephadex G-200 and polyacrylamide gel, RNA was isolated that is translated into histones 4 (H4) only. In addition, this RNA labelled in vitro with [I125] hybridizes to a restriction fragment of cloned sea urchin DNA known to contain the H4 gene.