Histone methylation regulates gene expression in the round spermatids to set the RNA payloads of sperm
Gene expression during spermatogenesis undergoes significant changes due to a demanding sequence of mitosis, meiosis and differentiation. Round spermatids have to prepare for DNA condensation as well as synthesize transcripts of genes required for the differentiation process. However, the mechanisms of gene activation and silencing in round spermatids remain largely unknown. We employed ChIP-seq to figure out the correlation of H3K4me3 and H3K9me3 marks with transcriptional activation and silencing in round spermatids. Out of about 2800 genes identified by H3K4me3 chipseq, transcriptome sequencing in purified round spermatids showed the presence of transcripts corresponding to about 64% of the genes. On the other hand, only about 25% of H3K9me3 enriched genes showed transcription in round spermatids, that too at very low levels. In conclusion, H3K4me3 enrichment in round spermatids correlates significantly with gene expression and H3K9me3 correlates with gene silencing, both of which are equally important for successful spermatogenesis. Overall design: Performed ChIP-Seq analysis of H3K4me3 and H3K9me3 in rat round spermatids.