Isolation of two murine H1 histone genes and chromosomal mapping of the H1 gene complement

The mammalian H1 histone gene complement consists of at least seven H1 protein isoforms. These include five S-phase-dependent H1 protein subtypes and two more distantly related proteins, which are expressed upon terminal differentiation (H1⁰) or during the pachytene stage of spermatogenesis (H1t). In the past, three replication-dependent murine H1 genes plus the H1 ⁰ and H1t genes have been isolated and characterized. In this report, we describe the sequences of two more H1 genes, and we show that all five murine replication-dependent H1 genes and the H1t gene map to the region A2-3 on Chromosome (Chr) 13. This is in agreement with our previous finding that the human H1 histone gene complement maps to 6p21.3, which corresponds to the A2-3 region on the murine Chr 13. Previous reports have shown that the replication-independent H1 ⁰ genes map to syntenic regions on Chrs 22 (human H1⁰) and 15 (murine H1 ⁰).