Long noncoding RNAs: new insights in modulating mammalian spermatogenesis

Abstract

Spermatogenesis is a complex differentiating developmental process in which undifferentiated spermatogonial germ cells differentiate into spermatocytes, spermatids, and finally, to mature spermatozoa. This multistage developmental process of spermatogenesis involves the expression of many male germ cell-specific long noncoding RNAs (lncRNAs) and highly regulated and specific gene expression. LncRNAs are a recently discovered large class of noncoding cellular transcripts that are still relatively unexplored. Only a few of them have post-meiotic; however, lncRNAs are involved in many cellular biological processes. The expression of lncRNAs is biologically relevant in the highly dynamic and complex program of spermatogenesis and has become a research focus in recent genome studies. This review considers the important roles and novel regulatory functions whereby lncRNAs modulate mammalian spermatogenesis.

Keywords: Germ cell; Long noncoding RNA; Mammalian spermatogenesis; Regulatory pathways; Spermatocytes.

Fig. 1

Schematic representation of the developmental processing of spermatogenesis

Fig. 2

The origin of lncRNA with relative to protein-coding genes structure in different genomic regions. The schematic sketch represents a and e for Noncoding regions; b and d for Protein coding genes; c for Intronic region and f for Cases of intronic retention region

Fig. 3

The location of lncRNA in relative to their nearby genes encoding protein

Fig. 4

Schematic drawings of the lncRNA archetypes (Adapted from [13, 14])