Table 1 Molecular mechanisms of epigenetic transgenerational heredity
Steps | Molecular mechanisms |
|---|---|
DNA sequence-invariant heritable traits | DNA methylation/histone post-translational modifications |
DNA methylation maintenance across cell division cycles | Hemimethylated DNA-guided, DNMT1-mediated CpG methylation pattern maintenance |
DNA demethylation | Passive DNA demethylation |
5-mC to 5-hmC conversion | |
Active DNA demethylation | |
Glycosylase-mediated base removal and base excision repair mechanisms | |
Histone code | Condensed chromatin |
HAT inactivation | |
HMT activation | |
Relaxed chromatin | |
HAT activation | |
HMT inactivation | |
Epigenetic modulation of mother-to-fetus transmission | Maternal nutrition status |
Maternal exposure to environmental toxins and food contaminants | |
BPA | |
Phthalates | |
Dioxins | |
Tobacco smoke | |
Cell differentiation and body development | Epigenetic signature reprogramming |
Erasure/reprogramming in the zygote (mitotic transmission) | |
Erasure/reprogramming in PGCs (meiotic transmission) | |
Gamete-carried transmission | |
DNA methylation profiles in sperm and oocytes | |
H3K4 and H3K27 histone methylation in sperm cells | |
RNA molecules carried by sperm cells (mRNA, non-coding RNA, miRNA, siRNA, piRNA) | |
Stem cell reprogramming | Epigenetic signature of induced pluripotency |
Decreased TETs/decreased hydroxymethylation at ES gene promoters | |
Reprogramming-resistant regions enriched for H3K9me3 |