Spermatid-specific linker histone HILS1 is a poor condenser of DNA and chromatin, and preferentially associates with LINE L1 elements

Background: Eleven linker histone subtypes are reported in mammals. Linker histones establish and maintain higher order chromatin structure. HILS1 is a spermatid-specific linker histone and its expression overlaps with the chromatin reorganization process during spermiogenesis; however, role of HILS1 in chromatin restructuring is largely unknown. Method: Genome-wide occupancy of the rat HILS1 protein was studied by ChIP-sequencing of pulldown DNA isolated from nuclei of 50-60 days old rat testis, using anti HILS1 antibody. Conclusion: Present study revealed that HILS1 is preferentially associated Line L1 elements in rat spermatids. Overall design: Nuclei of elongating/condensing spermatids cell types of the Rat (Rattus norvegicus) testicular cells were used for this purpose. Two runs were made with two different samples having two replicates each with a control for the ChIP used in each run. Illumina HiSeq 1000 sequencing platform was used with 101nt read length and paired end read type.