MicroRNA Alternations in the Testes Related to the Sterility of Triploid Fish

Abstract

The knowledge of understanding the molecular traits of the sterile triploid fish is sparse. Herein, we analyzed the microRNA (miRNA) alternations in the testes of the sterile triploid fish produced by crossing the tetraploid fish with the diploid fish, compared with those of tetraploids and diploids used as the controls. A total of 136, 134, and 142 conserved miRNAs and 105, 112, and 119 novel miRNAs were identified in the diploid, triploid, and tetraploid fish, respectively. The genes targeted by the differentially expressed miRNAs were identified and were enriched in the GO term cell surface receptor signaling pathway, cellular process, G-protein coupled receptor signaling pathway, and metabolic process. KEGG pathway enrichment was also assessed to evaluate the target genes with differentially expressed miRNAs and these genes were enriched in four pathways (synthesis and degradation of ketone bodies, pentose and glucuronate interconversions, cyanoamino acid metabolic process, and ascorbate and aldarate metabolism). Nine differentially expressed miRNAs were verified by quantitative real-time PCR analysis (qPCR). The upregulated miRNAs in triploids, including miR-101a, miR-199-5p, miR-214, miR-222, and miR-193a, showed the same results with high-throughput sequencing. Among the selected downregulated miRNAs, miR-7b and miR-153b had significantly lower expression levels in triploids. Dnah3 and Tekt1 genes targeted by miR-199-5p showed lower expression in triploids by qPCR. These verified differentially expressed miRNAs may participate in testicular development and sperm activity by targeting functional genes, which were identified with differential expression in the triploid. This evidence provides insights into the epigenetic regulatory mechanisms of sterility in triploid cyprinids.

MicroRNAs Involved in the Regulation of LC-PUFA Biosynthesis in Teleosts: miR-33 Enhances LC-PUFA Biosynthesis in Siganus canaliculatus by Targeting insig1 which in Turn Upregulates srebp1

“…In land animals, miRNAs generally exhibit a negative regulatory effect on gene expression and are involved in a number of biological processes (Alvarezgarcia and Miska 2005;Carrington et al 2003;Xu et al 2003). Post-transcriptional regulatory mechanisms have been shown to play important roles in LC-PUFA biosynthesis and glycolipid metabolism, as well as growth, development, reproduction and immune function in teleosts (Gong et al 2015;Her et al 2011;Siddique et al 2016;Škugor et al 2014;Tao et al 2018;Zhang et al 2014;Zhu et al 2015). In rabbitfish, miR-17 was found to be involved in the regulation of LC-PUFA biosynthesis by targeting Δ4 fads2 (Zhang et al 2014).…”

Role of sex‐biased miRNAs in teleosts – a review

“…Higher expression of miR-33a and miR-135b in tilapia testis has been correlated with maturation of testis via regulation of insulin signalling pathway (Xiao et al 2014). Tao et al (2018) also observed the importance of miR-21, miR-22a, miR-99, miR-100, miR-101a and miR-146a in testicular development (Tables 2,3).…”

“…Bizuayehu et al (2012) not only reported the expression of sex-biased miRNAs in Atlantic halibut but also demonstrated the mediation of miRNA regulation via signals from neuroendocrine system. Another study analysed the miRNA transcriptomes from fish at different ploidy levels to demonstrate the epigenetic regulation sterility in triploid cyprinids (Tao et al 2018). The discovery of novel miRNAs in teleost gonads further broadens the horizon for the exploration of their functions in reproductive control.…”

“…While miR129-3p and miR-727-3p showed a higher expression in mature females of Nile tilapia, mature males showed an increased expression in miR-132a and miR-212 (Xiao et al 2014). Similar to mammals, miR-143 was found to enriched in testis and implicated in spermatogenesis (Xiao et al 2014;Tao et al 2018). MiR-181a family was also found to be highly expressed in both male and female tilapia gonads.…”

Screening, Identification and Interaction Analysis of Key MicroRNAs and Genes in Asthenozoospermia

“…It also seemed to be one of the best normalizing miRNA candidates associated with spermatogenesis and embryogenesis [31]. miR-193a was upregulated in sterile triploid sh which might take part in sperm activity and testicular development by targeting functional genes [32]. miR-34b expression in asthenozoospermia group was also signi cantly lower compared to control group [20].…”