Yoshinori Yamamoto, Toru Watanabe, Mayu Nakamura, Norikazu Kakubayashi, Yusuke Saito and Yoshinori Matsuo
Histone 4 replacement (H4r) can replace replication-dependent H4 in Drosophila. To study the evolution of epigenetic mechanisms, the H4 and H4r genes from 14 Drosophila species were compared with regard to gene arrangement, codon bias and flanking sequences. Although the amino acid sequences of H4 and H4r are identical or nearly identical, the gene structures are quite different. The H4r gene is a single copy gene located 3R88C9 in D. melanogaster between punt and CEP78K, as it is in 11 closely related Drosophila species, but not in the three distantly related species. The H4r gene, unlike the H4 gene, has two introns and generates polyadenylated transcripts. The codon usage bias at particular sites differed between H4r and H4. The H4r gene had more GC pairs at 3rd codon position. Strongly conserved signal sequence was not found in the 5’-region or 3’-region of the H4r gene. These results suggested that the post transcriptional process such as modifying histone at or after translation will be important for replacing histones and remodeling the chromatin. The evolutionary changes that affect gene structure and codon usage might be a key step to develop epigenetic systems by replacement histones.
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Journal of Phylogenetics & Evolutionary Biology received 911 citations as per Google Scholar report
