RNAs in Mature Spermatozoa

The nucleus of mature sperm contains a complex population of transcripts such as mRNAs and miRNAs which expressed and accumulated during process of spermatogenesis; however in spermatozoa، transcription is inert. The spermatozoa do not have cytoplasmic ribosomal compounds and translation apparatus. However، spermatozoa can translate cytoplasmic mRNAs de novo، using mitochondrial polysomes. Important roles of spermatozoa RNAs include chromatin repackaging، paternal genomic imprintingand gene silencing. Recent information of transferred spermatozoa RNAs into oocytes during fertilization and RNA-mediated epigenetic effect contribute extra genomically to early embryonic growth. Furthermore، regardless of the biological roles of spermatozoal RNA and embryonic growth، the differences in profile expression of spermatozoa RNAs from fertile and infertile men، provide potential spermatozoa markers in assessment male fertility and infertility. In this review، presence of RNAs in mature sperm، diversity and functions of gene transcripts in male fertility and embryonic development are discussed.