Dynamics of 5-hydroxymethylcytosine duringmouse spermatogenesis

摘要

Little is known about how patterns of DNA methylation change during mammalianspermatogenesis. 5hmC has been recognized as a stable intermediate of DNA demethylationwith potential regulatory functions in the mammalian genome. However, its global pattern ingerm cells has yet to be addressed. Here, we first conducted absolute quantification of5hmC in eight consecutive types of mouse spermatogenic cells using liquid chromatographytandemmass spectrometry, and then mapped its distributions in various genomic regionsusing our chemical labeling and enrichment method coupled with deep sequencing.We foundthat 5hmC mapped differentially to and changed dynamically in genomic regions related toexpression regulation of protein-coding genes, piRNA precursor genes and repetitive elements.Moreover, 5hmC content correlated with the levels of various transcripts quantified byRNA-seq. These results suggest that the highly ordered alterations of 5hmC in the mousegenome are potentially crucial for the differentiation of spermatogenic cells.