ISOLATION AND CHARACTERIZATION OF 2 REPLICATION-DEPENDENT MOUSE H1 HISTONE GENES

Mice contain at least seven nonallelic forms of the H1 histones, inclu ding the somatic variants H1a-e and less closely related variants H1 d egrees and H1t. The mouse H1 degrees and H1c (H1var.1) genes were isol ated and characterized previously. We have now isolated, sequenced and studied the expression properties of two additional mouse H1 genes, t ermed H1var.2 and H1var.3. Extensive amino acid and nucleotide sequenc e comparisons were made between the two genes and other mammalian H1 h istone genes. A high degree of nucleotide sequence identity was seen b etween the H1var.2, rat Hid and human H1b genes, even well beyond the coding region, indicating that these genes are likely homologues. Unli ke the previously characterized mouse H1var.1 gene which produces both nonpolyadenylated and polyadenylated mRNAs, the H1var.2 and H1var.3 g enes produce only typical, replication dependent, nonpolyadenylated mR NAs.