Fig. 6

Model of H1t-containing chromatin domains in pachytene spermatocytes. a, b Extranucleolar localization of linker histone variant H1t is related to a LINE and b LTR repeat-element chromatin domains. This forms a chromatin template for binding of PIWI proteins, DNA methylation machinery (forming methylated CpGs), repressive histone modifications like H3K9me3 and H4K20me3 in pachytene spermatocytes. H3K9me3 nucleosomes are binding sites for HP1 proteins to mediate heterochromatinization at these target loci. c Predominant association of linker histone variant with the intergenic spacer of the rDNA element. H1t co-associates with methylated CpGs and nucleolar proteins like Npm1 at the rDNA element in pachytene-enriched P20 mouse testicular cells. d Alignment of protein sequences of mouse H1t with Drosophila H1. Both these proteins lack DNA-binding motifs like S/TPKK in its C-terminal domain