Small RNAs in spermatogenesis

Abstract

Spermatogenesis is characterized by meiotic divisions and major morphological changes to produce spermatozoa that are capable of independent movement and fertilization of an egg. Male germ cell differentiation is governed by orchestrated, phase-specific gene expression patterns that are tightly controlled at transcriptional and post-transcriptional level. Post-transcriptional regulation of protein-coding mRNAs becomes prominent during the late steps of spermatogenesis when the compacting sperm nucleus becomes transcriptionally inhibited. Small non-coding RNAs are important regulators of gene expression that mainly function post-transcriptionally to control the properties of their target mRNAs. Male germ cells express several classes of small RNAs, including Dicer-dependent microRNAs (miRNAs) and endogenous small interfering RNAs (endo-siRNAs), as well as Dicer-independent piwi-interacting RNAs (piRNAs). Increasing evidence supports the essential role of small RNA-mediated RNA regulation in normal spermatogenesis and male fertility.

Keywords: AGO; Argonaute protein; CB; Fertility; Germ cell; MSCI; Non-coding RNA; PGC; PIWI-interacting RNA; PND; Post-transcriptional; RISC; RNA-induced silencing complex; RNP; SSC; Small RNA; Spermatogenesis; TE; chromatoid body; endo-siRNA; endogenous small interfering RNA; meiotic sex chromosome inactivation; miRNA; microRNA; piRNA; post-natal day; primordial germ cell; ribonucleoprotein; siRNA; small interfering RNA; spermatogonial stem cell; transposable element.