Small RNAs Present in Semen and Their Role in Reproduction

Abstract Since the discovery of the small noncoding RNAs (sncRNAs), several studies have showed their essential role in the regulation of gene expression in most eukaryotic cells. Conditional inactivation of genes involved in the biogenesis and function of sncRNAs in germinal cells and epididymal cells has revealed that sncRNAs are necessary for sperm development and maturation. Characterization of the sncRNA populations present in sperm and seminal plasma by high-throughput technologies has emerged as an invaluable tool to understand some regulatory mechanisms occurring during sperm generation. In addition, comparative profiling of sncRNAs among fertile and infertile patients sheds light on some potential pathogenic mechanisms associated to male infertility that could derive in the discovery of new molecular biomarkers with valuable clinical significance. Growing evidences suggest that sncRNAs in semen not only represent leftovers from spermatogenic processes but also may play important roles in early embryogenesis and epigenetic inheritance of acquired traits.