Shangguan Aishao, Zhou Hao, Sun Wei, Ding Rui, Li Xihe, Liu Jiajia, Zhou Yang, Chen Xing, Ding Fengling, Yang Liguo, Zhang Shujun
Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China.
Inner Mongolia Saikexing Institute of Breeding and Reproductive Biotechnology in Domestic Animal, Hohhot, China.
Front Genet. 2020 May 5;11:419. doi: 10.3389/fgene.2020.00419. eCollection 2020.
Although cryopreservation of bull semen is widely used commercially in the livestock breeding industry, cryopreservation results in low fertility of bull sperm. As an important regulatory factor, the alteration of small non-coding RNA (sncRNA) profile during cryopreservation of bull sperm is not yet completely known. In the present study, we sequenced sncRNAs of frozen and fresh sperm to study the link of alteration of the sncRNA profiles (particularly in miRNAs and mRNA fragments) with low sperm fertility caused by cryopreservation. We identified 55 miRNAs and 526 mRNA fragments differentially expressed (DE) between frozen and fresh sperm. Subsequently, the functional analysis revealed that targeted genes of DE miRNAs in sperm had roles in the fertilization, ATP, and apoptosis. Instead, targeted genes of DE miRNAs in cow metaphase II oocyte were significantly enriched in the MAPK signaling pathway, autophagy-animal pathway, and mitophagy-animal pathway. Additionally, biological processes of DNA repair, spermatid development, response to temperature stimulus, and cellular response to DNA damage stimulus were enriched by mRNA fragments. In conclusion, we found that DE miRNAs or DE mRNA fragments in cryopreservation may influence the fertility of sperm, these findings will provide the reference to improve the cryopreservation technology of bull semen.
尽管牛精液的冷冻保存已在畜牧养殖业中广泛应用于商业用途，但冷冻保存会导致牛精子的受精能力较低。作为一个重要的调控因子，在牛精子冷冻保存过程中小非编码RNA（sncRNA）谱的变化尚未完全明确。在本研究中，我们对冷冻精子和新鲜精子的sncRNA进行了测序，以研究sncRNA谱（特别是在miRNA和mRNA片段方面）的变化与冷冻保存导致的精子低受精能力之间的联系。我们鉴定出了55种miRNA和526个在冷冻精子和新鲜精子之间差异表达（DE）的mRNA片段。随后，功能分析表明，精子中差异表达的miRNA的靶向基因在受精、ATP和凋亡过程中发挥作用。相反，在牛中期II卵母细胞中差异表达的miRNA的靶向基因在MAPK信号通路、自噬-动物通路和线粒体自噬-动物通路中显著富集。此外，DNA修复、精子细胞发育、对温度刺激的反应以及对DNA损伤刺激的细胞反应等生物学过程被mRNA片段富集。总之，我们发现冷冻保存过程中差异表达的miRNA或差异表达的mRNA片段可能会影响精子的受精能力，这些发现将为改进牛精液冷冻保存技术提供参考。
