microRNA profiling in three main stages during porcine spermatogenesis

Abstract

Background Spermatogenesis is an intricate biological event wherein an undifferentiated spermatogonium develops into mature sperms. MicroRNAs are a type of single strand small non-coding RNA molecule and are implicated in the regulation of many crucial pathways during cell proliferation, apoptosis, and differentiation.Method Here, we present a comprehensive comparison of miRNA expression profiling in three main stages during porcine spermatogenesis using high-throughput sequencing. Results We built three small RNA libraries for the testis, the epididymis and the ejaculated sperm from a Landrace boar, and in total obtained 3821 precursor hairpins encoding for 4761 mature miRNAs, of which 23 are miRNA*. Notably, Zonggang Luo and Yingkai Liu contributed equally to this work.Capsule ZGL carried out the molecular genetic studies, participated in the sequence alignment, and revised themanuscript. YKL participated in the study design and drafted the manuscript. LC carried out the RT-PCR and data analysis. ME participated in the experiment. Assist Reprod Genet (2015) 32:451-460 DOI 10.1007 940 precursor miRNAs produced both the 5'-and 3'-strands as sister pairs, indicating the distinctive expression patterns of germ cell miRNAs. Additionally, 418 out of 710 co-expressed miRNAs were identified as being differentially expressed between libraries (P<0.001). Apart from the sexual specific X chromosome, many miRNAs were found to be located on chromosome 12, which may play potential roles in spermatogenesis according to the result of synteny analysis with human and mouse. The Gene Ontology and KEGG pathway analysis revealed that the target genes of co-expressed miRNAs were highly involved in the cell cycle process, metal ion binding, modification of plasma membrane, and the p53 signal pathway.

Roles of microRNAs in mammalian reproduction: from the commitment of germ cells to peri‐implantation embryos

“…In mice, the abundance of miR-485 and miR-878-5p changes in a time-dependent manner in the ovary and testes and may be crucial for sex specification (Rakoczy et al, 2013). Similarly unique and differential expression of miRNAs is reported in the testes (Watanabe et al, 2006;Luo et al, 2010;Yang et al, 2013a;Luo et al, 2015b) and ovaries (Choi et al, 2007;Liang et al, 2007;Ahn et al, 2010;Nothnick, 2012;Xiao et al, 2014; as well as other reproductive organs and tissues including testicular somatic cells (Rakoczy et al, 2013), epididymis (Belleannee et al, 2012;Chu et al, 2015;Nixon et al, 2015aNixon et al, , 2015b, fallopian tube (Nothnick, 2012), uterus (Nothnick, 2012 and cervix (Nothnick, 2012) of different mammalian species. Several miRNAs (such as let-7, miR-503, miR-672, miR-465, miR-21-5p and miR-143-3p) could play a housekeeping role (Ahn et al, 2010; and the miR-34 family can be considered as a fertility biomarker (Tscherner et al, 2014) in both sexes.…”

“…Ochratoxin‐A treatment induces extensive apoptosis of male germ cells, while inhibition of miR‐122 minimizes this Ochratoxin‐A‐mediated toxicity (Chen et al, ), indicating that miR‐122 is a critical regulator for the germ cell apoptosis‐induction pathway. In pigs, expression of miR‐16 and miR‐34 regulates the cell cycle progression during spermatogenesis and senescence of sperm (Luo et al, ). miR‐16 promotes the apoptosis of immortalized GC‐1 spermatogonia cells (GC‐1 SPG) by downregulating Ccnd1 (Li et al, ).…”

“…A panel of miRNAs was detected in human and mouse testes (Watanabe et al, 2006). Among these miRNAs, miR-449a is abundant in both mouse and human testes (Luo et al, 2015b). In boar testes, a subset of miRNAs are expressed differentially between mature and immature testes (Luo et al, 2010) and regulates stage-specific testicular gene expression.…”

Paternal contribution to development: Sperm genetic damage and repair in fish

“…Some evidences point to a great variety of biological processes in which miRNAs are involved, including among others embryo development, cell proliferation or apoptosis (Wang and Xu 2015). Dicer1 or Drosha knockout mouse models, in which miRNA processing is compromised, resulted also in impaired spermatogenesis and fertility after birth due to faulty germ cell proliferation (Maatouk et al 2008;Wu et al 2012).The essential and multiple functions played by miRNAs during spermatogenesis have been largely evaluated (Jodar et al 2013;Kotaja 2014;Luo et al 2015). In addition, an implication of paternal miRNAs in embryo development has been hypothesized because the potential capacity for repressing translation of zygotic transcripts, or regulating transcription by interaction with specific promoters (Jodar et al 2013).…”

>b<Perfil de microRNAs presentes no sêmen e embriões bovinos e sua relação com a fertilidade>/b<

“…Os miRNAs, por serem reguladores pós-transcricionais, possuem grande potencial na modulação das características reprodutivas. Diversos estudos já mostraram o papel dessas moléculas na espermatogênese, na maturação espermática e no desenvolvimento embrionário inicial (KRAWETZ et al, 2011;LIU et al, 2012;HU et al, 2013;KOTAJA, 2014;YADAV;KOTAJA, 2014;LUO et al, 2015;NIXON et al, 2015;YUAN et al, 2016). Existem evidências de que os miRNAs presentes no sistema reprodutivo possuem alta regulação apresentando, por exemplo, diferentes perfis ao longo do epidídimo (BELLEANNÉE et al, 2013).…”