At the embryonic stage, the germ cell linage is speciﬁed and segregated early in mammalian development. Germ granules are evolutionarily conserved, non-membranous cytoplasmic structures that contain ribonucleoproteins and are exclusive to the germline.
During embryonic germ cell development, ﬁrst somatic epigenetic marks are almost all removed and then novel sex-speciﬁc DNA methylation patterns are established in a sex-speciﬁc manner. The process is typically divided into 3 steps: mitosis, meiosis and spermatogenesis. Firstly, spermatogonia are renewed through mitotic divisions; in the second step, spermatogonia differentiate to generate primary spermatocytes that undergo two meiotic divisions to generate secondary spermatocytes and haploid spermatids; ﬁnally, haploid spermatids undergo several morphological changes such as acrosome and ﬂagellum formation, nuclear condensation and cytoplasm reorganization to give rise to the spermatozoa.
Non-coding RNAs (ncRNAs) present a high diversity of sizes and serve as controllers of gene expression. Their role has been shown to be at the transcriptional or post-transcriptional level. SncRNAs are crucial regulators of gene expression controlling the fate of their target RNAs, mainly at the post-transcriptional level.
It is interesting to control these pathways for male contraception as well as for diagnostic or treatment proposes in the cases of testicular cancer or male infertility.