Table 4.
Characteristics of the studies which analyzed the epigenetic impairment of spermatogenesis.
| Epigenetic modifications | Effects | Study type | Species | References |
|---|---|---|---|---|
| Histone methylation | • Decrease of DNMT • Reduction in the global DNA methylation levels in spermatogonia |
In vitro | Mouse | (30) |
| DNA methylation | • No effect on DNA methylation of imprinted genes (IGF2, IGF2R, PEG3. and H19) in germ cells • Increase in ERα expression • Impairment of meiotic progression of germ cells • Decrease in quality and quantity of spermatozoa |
In vivo | Mice | (31) |
| DNA methylation | • Reduction in DNA replication capacity • Alteration of the genome-wide DNA methylation level in GC-2 cells • Alteration of DNMT expression levels • Regulation of MYBPH and PRKCD methylation |
In vivo | Mouse | (32) |
| DNA methylation | Promotion of the DNA methylation process in the testes by novo synthesis of glutathione and oxidative stress | In vivo | Fish | (33) |
| DNA methylation | Alteration of the global DNA methylation level of gonads | In vivo | Fish | (34) |
| DNA methylation | • Alteration of the global DNA methylation level of gonads • Transcriptional change of genes (DNMTS, GNMT, and TEST) |
In vivo | Fish | (35) |
| DNA methylation | Variation in DNA methylation levels | In vivo | Fish | (36) |
| DNA methylation | Hypermethylation of global DNA in the testes | In vivo | Fish | (37) |
| DNA methylation | Global DNA demethylation | In vivo | Fish | (38) |
| DNA methylation | • Decrease of spermatocytes • Increase in apoptosis • Downregulation of CCNB1 and SYCP3 • Upregulation of GPER1 and ESRRGA receptors • Miss-regulation of epigenetic remodeling enzyme transcripts • DNA hypermethylation • H3K27me3 demethylation • Increase in histone acetyltransferase activity |
In vitro | Fish | (39) |
| DNA methylation | • Di-methylation of lysine K4 on histones H3 • Impairment of motility, concentration, and mitochondrial activity in sperm |
In vivo | Human | (40) |
| DNA methylation | Trimethylation of histone 3 (H3K27me3, H3K4me2, or H3K4me3) in sperm | In vivo | Human | (41) |
| DNA methylation | Hypomethylation of LINE-1 | In vivo | Human | (42) |
| DNA methylation | • Decrease in sperm LINE-1 methylation status • Association between BPA urinary levels and low semen quality |
In vivo | Human | (43) |
| DNA methylation | • Correlation between 5hmC rates of AChE and low sperm motility • Correlation between HoxC4 promoters and sperm concentration |
In vivo | Human | (44) |