Genetic and epigenetic mechanisms of spermatogenesis – long process with many stages regulation are discussed. DNA code is the entirety of hereditary information, epigenetic mechanisms of gene regulation act without altering primary nucleotide sequences. Epigenetic regulation is a complex process, in which components of different groups of epigenetic modifications (non-coding RNAs, DNA methylation and histone modification) work together. Mistakes in any of the components of the process may cause impaired spermatogenesis and/or infertility, and may cause epigenetic diseases. 

Nowadays 90 imprinted genes and loci on 13 chromosomes are revealed. More then 10 human diseases involving genomic imprinting are known (Angelman syndrome, Prader–Willi syndrome, Russell–Silver syndrome, Beckwith–Wiedemann syndrome etc.). DNA methylation is essential for normal development and is associated with a number of key processes including animal growth and development, transcription, DNA replication and reparation, cell differentiation, genomic imprinting, X-chromosome inactivation, suppression of repetitive elements and carcinogenesis.