IDENTIFICATION AND CHARACTERIZATION OF THE DROSOPHILA HISTONE H4 REPLACEMENT GENE

Replacement variant genes for different histones have been described i n most higher eukaryotes, However, so far no such gene has been found for histone H4. We have isolated from both Drosophila melanogaster and D. hydei a novel histone H4 encoding gene, H4r, which displays all th e properties of a histone replacement variant gene: it contains intron s, generates polyadenylated mRNA, represents the predominant H4 transc ript in non-dividing tissues and is present in the genome as a single copy, The encoded polypeptide is identical to the Drosophila cell-cycl e regulated histone H4, The fact that it is a single copy gene makes i t prone to genetic analysis and it might be a useful tool for studying nucleosome structure and function.