Transcriptome profiling of histone writers/erasers enzymes across spermatogenesis, mature sperm and pre-cleavage embryo: Implications in paternal epigenome transitions and inheritance mechanisms

Abstract

Accumulating evidence put on the focus that male spermatogenesis presents windows of vulnerability for epigenetic reprogramming by environmental stressors that not only can affect fertility but even transmit developmental, metabolic, and behavioral traits to offspring. This work analyzed the transcriptomic programs of epigenetic enzymes involved in histone K acetylation and methylation from undifferentiated spermatogonia to mature sperm and pre-cleavage zygote in the mouse. We dissected the peak expression at each stage for families and individual enzymes, their target histone PTMs functions and reported dynamics during spermatogenesis and early embryogenesis. This approach allowed us to identify epigenetic enzymes with known functions during spermatogenesis and, by the rule of guilty by association, many others not even described yet in male germ cell development. Moreover, some of these enzymes mRNA were detected higher in the pre-cleavage zygote than in the transcriptionally silent MII oocyte, suggesting a paternal contribution. Our study contributes to the mechanistic aspects behind transgenerational epigenetics, described for the first time in such a comprehensive approach.