163 Sperm small noncoding RNA biomarkers associated with ram fertility

Maintaining reproductive effectiveness and output profitability in sheep farming depends on accurately estimating ram fertility. However, development in animal science and technology is hindered by a lack of reliable biomarkers for estimating ram fertility and semen quality. The goal of this study was to ascertain small noncoding RNAs (sncRNAs) in sperm from rams with distinct fertility phenotypes. Mature rams were grouped into two groups: high and low fertility (HF, n = 31, 94.5 ± 2.8%; LF, n = 25, 83.1 ± 5.73%; P = 0.028) according to the pregnancy rates sired by the rams (average pregnancy rate, 89.4 ± 7.2%). Total RNAs were extracted from sperm of the highest- and lowest-fertility rams (n = 4; pregnancy rate, 99.2 ± 1.6% and 73.6 ± 4.4%, respectively) followed by next-generation sequencing of the transcripts. The small RNA tags were mapped to reference sequence by Bowtie. mirdeep2 was used to identify known and novel miRNAs. We identified 888 557 sncRNAs from the sperm of HF and LF rams; 659 343 of these sncRNAs were known miRNAs. However, we found 1673 known miRNAs, while 627 were novel miRNAs from HF and LF sperm. We showed that oar-let-7b, oar-miR-143, oar-miR-200c, and oar-miR-200b were differentially expressed between HF and LF sperm. Targets of the differentially expressed miRNAs were enriched in the KEGG Pathway of PI3K-Akt signaling pathway (oas04151), Focal adhesion (oas04510), and Rap1 signaling pathway (oas04015). The results of this work indicate the possibility of using sncRNA biomarkers to assess ram sperm quality, estimate sperm fertility, and conduct breeding soundness tests for precision livestock farming.