Sperm and seminal plasma microRNAs in the context of bull sperm fertility

Spermatogenesis consists of mitotic proliferation of spermatogonia, meiosis of spermatocytes, haploid differentiation of spermatids, and genesis of male gametes. Male germ cells have a complex transcriptome. Phase-specific gene expression patterns are seen by the active transcription of the genome of male germ cells, however new RNAs are not transcribed in haploid sperm. The RNAs originated from the diploid germ stem cells are carried to the oocyte upon fertilization. Sperm have protein-coding messenger RNAs, and many noncoding RNAs, including microRNAs (miRNAs). The miRNAs regulate gene expression, mainly by repressing post-transcription or by inhibiting translation of their target messenger RNAs. Clinical studies have exploited the well-defined profiles of miRNAs in sperm and seminal plasma, and human sperm or seminal plasma miRNAs have been proposed as potential biomarkers for male factor infertility ...