H3 and H4 histone cDNA sequences from Xenopus: a sequence comparison of H4 genes

摘要

Ovarian poly (A)+ RNA from Xenopus laevis and Xenopua borealis was used to construct two cDNA libraries which were screened for histone sequences. cDNA clones to H4 mRNA were obtained from both species and an H3 cDNA clone from Xenopus laevis. The complete DNA sequences of these clones have been determined and are presented. These new sequences are compared with other H3 and H4 DNA sequences both in the coding and 3′ noncoding regions. We find that there is considerable non-random codon usage in ten H4 genes. In addition there are some sequence similarities in the ′' noncoding regions of H3 and H4 genes.