Animal Genomics Group, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB, Cerdanyola del Vallès, Barcelona, Catalonia, Spain.
Unit of Animal Science, Department of Animal and Food Science, Autonomous University of Barcelona, Cerdanyola del Vallès, Barcelona, Catalonia, Spain.
Sci Rep. 2020 May 14;10(1):7985. doi: 10.1038/s41598-020-64711-z.
Circular RNAs (circRNAs) are emerging as a novel class of noncoding RNAs which potential role as gene regulators is quickly gaining interest. circRNAs have been studied in different tissues and cell types across several animal species. However, a thorough characterization of the circRNAome in ejaculated sperm remains unexplored. In this study, we profiled the sperm circRNA catalogue using 40 porcine ejaculates. A complex population of 1,598 circRNAs was shared in at least 30 of the 40 samples. Generally speaking, the predicted circRNAs presented low abundances and were tissue-specific. Around 80% of the circRNAs identified in the boar sperm were reported as novel. Results from abundance correlation between circRNAs and miRNAs together with the prediction of microRNA (miRNA) target sites in circRNAs suggested that circRNAs may act as miRNA sponges. Moreover, we found significant correlations between the abundance of 148 exonic circRNAs and sperm motility parameters. Two of these correlations, involving ssc_circ_1458 and ssc_circ_1321, were confirmed by RT-qPCR using 36 additional samples with extreme and opposite sperm motility values. Our study provides a thorough characterization of circRNAs in sperm and suggests that circRNAs hold potential as noninvasive biomarkers for sperm quality and male fertility.
环状 RNA（circRNAs）作为一类新的非编码 RNA，其作为基因调控因子的潜在作用正引起越来越多的关注。circRNAs 已在多种动物物种的不同组织和细胞类型中进行了研究。然而，对射出精子中的 circRNA 组进行全面描述仍有待探索。在这项研究中，我们使用 40 个猪精液样本对精子 circRNA 目录进行了分析。至少在 40 个样本中的 30 个样本中共享了一个复杂的 1598 个 circRNA 群体。一般来说，预测的 circRNAs 丰度较低且具有组织特异性。在公猪精子中鉴定出的 circRNAs 中，约有 80%被报道为新的。circRNAs 与 miRNAs 之间丰度相关性的结果以及 circRNAs 中 miRNA 靶位点的预测表明，circRNAs 可能作为 miRNA 的海绵。此外，我们发现 148 个外显子 circRNAs 的丰度与精子运动参数之间存在显著相关性。其中两个相关性，涉及 ssc_circ_1458 和 ssc_circ_1321，通过使用具有极端和相反精子运动值的 36 个额外样本的 RT-qPCR 得到了验证。本研究对精子中的 circRNAs 进行了全面描述，并表明 circRNAs 可能作为精子质量和男性生育力的非侵入性生物标志物具有潜力。
