Characterization of the small RNA population in Human spermatozoa

Small noncoding RNAs (sncRNA) are becoming recognized for their participation in a diverse range of cellular functions. In this study, their global characterization in human spermatozoa from donors with proven fertility was undertaken. Reads were analyzed in two classes, those mapping to unique locations and those that could be aligned to up to 10 genomic locations. All libraries showed comparable distribution of reads between intergenic, intronic and exonic genomic regions. Analysis of the sequences revealed the presence of multiple small RNA classes. The miRNAs retained in spermatozoa were found to be associated with promoter regions, suggestive of a role at the transcriptional level. Piwi-interacting sncRNAs as well as repeat-associated small RNAs were identified for the first time in mature spermatozoa from a mammalian species. Human spermatozoa retain a multifaceted population of small non-coding RNAs. Their presence is consistent with the view that they may function to stabilize the genome as part of the confrontation and consolidation of the genomes at fertilization. Overall design: Examination of sperm samples from 3 individuals, sequenced individually