Cloning and analysis of the coding region of the histone H1 degrees-encoding gene from rat PC12 cells

We have determined the complete coding sequence of the histone-encoding H1 degrees gene from rat PC12 cells. Southern and Northern analyses suggest that rat H1 degrees is encoded by a single-copy gene which generates an mRNA of about 2.2 kb, Comparison of the rat, mouse and human amino-acid sequences shows that the C-terminal domain of the protein is much more variable than the N-terminal and central domains. Rates of non-synonymous and synonymous nucleotide substitution have been calculated. The rate of non-synonymous substitution is about 2.5-times higher in the rodent lineage than in the human lineage.