Martinez Cristina A, Roca Jordi, Alvarez-Rodriguez Manuel, Rodriguez-Martinez Heriberto
Department of Biomedical & Clinical Sciences (BKV), BKH/Obstetrics & Gynaecology, Faculty of Medicine and Health Sciences, Linköping University, SE-58185 Linköping, Sweden.
Department of Medicine and Animal Surgery, Faculty of Veterinary Medicine, University of Murcia, 30100 Murcia, Spain.
Biology (Basel). 2022 Feb 1;11(2):236. doi: 10.3390/biology11020236.
MicroRNAs (miRNAs) are short non-coding RNAs (20-25 nucleotides in length) capable of regulating gene expression by binding -fully or partially- to the 3'-UTR of target messenger RNA (mRNA). To date, several studies have investigated the role of sperm miRNAs in spermatogenesis and their remaining presence toward fertilization and early embryo development. However, little is known about the miRNA cargo in the different sperm sources and their possible implications in boar fertility. Here, we characterized the differential abundance of miRNAs in spermatozoa from the terminal segment of the epididymis and three different fractions of the pig ejaculate (sperm-peak, sperm-rich, and post-sperm rich) comparing breeding boars with higher (HF) and lower (LF) fertility after artificial insemination (AI) using high-output small RNA sequencing. We identified five sperm miRNAs that, to our knowledge, have not been previously reported in pigs (mir-10386, mir-10390, mir-6516, mir-9788-1, and mir-9788-2). Additionally, four miRNAs (mir-1285, mir-92a, mir-34c, mir-30), were differentially expressed among spermatozoa sourced from ejaculate fractions and the cauda epididymis, and also different abundance was found between HF and LF groups in mir-182, mir-1285, mir-191, and mir-96. These miRNAs target genes with key roles in fertility, sperm survival, immune tolerance, or cell cycle regulation, among others. Linking the current findings with the expression of specific sperm proteins would help predict fertility in future AI-sires.
微小RNA（miRNA）是短链非编码RNA（长度为20 - 25个核苷酸），能够通过与靶信使RNA（mRNA）的3'-非翻译区完全或部分结合来调节基因表达。迄今为止，已有多项研究探讨了精子miRNA在精子发生中的作用及其在受精和早期胚胎发育过程中的残留情况。然而，对于不同精子来源中的miRNA含量及其对公猪生育力的潜在影响知之甚少。在此，我们使用高产量小RNA测序技术，比较了人工授精（AI）后生育力较高（HF）和较低（LF）的种公猪，对附睾末端精子以及猪射精的三个不同部分（精子峰值、富含精子和精子后富含部分）中的miRNA差异丰度进行了表征。我们鉴定出了5种精子miRNA，据我们所知，此前在猪中尚未有过报道（mir - 10386、mir - 10390、mir - 6516、mir - 9788 - 1和mir - 9788 - 2）。此外，4种miRNA（mir - 1285、mir - 92a、mir - 34c、mir - 30）在射精部分和附睾尾来源的精子中差异表达，并且在mir - 182、mir - 1285、mir - 191和mir - 96中，HF和LF组之间也发现了不同的丰度。这些miRNA靶向在生育力、精子存活、免疫耐受或细胞周期调控等方面起关键作用的基因。将当前研究结果与特定精子蛋白的表达联系起来，将有助于预测未来AI种公猪的生育力。
