High impact information on H4

• Positive and negative transcriptional regulatory elements in the early H4 histone gene of the sea urchin, Strongylocentrotus purpuratus [1].
• Comparisons of protein-coding sequences of late H4 and H2B genes with their early counterparts showed that silent sites have diverged to the theoretical maximum, indicating that early and late histone gene classes diverged at least 200 million years ago [2].
• The organization of these genes is similar to the divergently transcribed H3-H4 gene pairs of Lytechinus pictus [3].
• Whole genome Southern analysis indicates that most late H3 and H4 genes are organized as pairs in both sea urchin genomes [3].
• The transition from early (E) to late (L) histone gene expression in developing sea urchin (Strongylocentrotus purpuratus) embryos was examined for H2B, H3, and H4 mRNAs by in situ hybridization of class-specific probes [4].

Biological context of H4

• The nucleotide sequences of late and early S. purpuratus H3 and H4 genes differ in the coding regions by 17.0% and 15.7%, respectively [3].
• A gene pair coding for histones H3 and H4 expressed during late embryonic development has been cloned from the S. purpuratus genome [3].
• Analysis of promoter regions shows clear homologies among Mytilus H1 genes, sea urchin H1 genes, and vertebrate differentiation-specific H1 subtypes (H5 and H1(o)), all having an H4 box motif in common [5].

Analytical, diagnostic and therapeutic context of H4

• Restriction enzyme mapping and homoduplex analysis of this fragment indicate that the H1-H4 spacer of one repeat is situated alongside the inverted H2A-H1 spacer of another repeat [6].
• Sequence analysis and evolution of sea urchin (Lytechinus pictus and Strongylocentrotus purpuratus) histone H4 messenger RNAs [7].

References