Table2_Discovery of Differentially Expressed MicroRNAs in Porcine Ovaries With Smaller and Larger Litter Size.XLSX

The number of live births in a litter is an important reproductive trait, and is one of the main indicators which reflect the production level and economic benefit of a pig farm. The ovary is an important reproductive organ of the sow, and it undergoes a series of biological processes during each estrous cycle. A complex transcriptional network containing coding and non-coding RNAs in the ovary closely regulates the reproductive capability of sows. However, the molecular regulation mechanisms affecting sow litter size are still unclear. We investigated the expression profiles of microRNAs (miRNAs) in porcine ovaries from sows with smaller than average litter sizes (SLS) and those with larger litter sizes (LLS). In total, 411 miRNAs were identified, and of these 17 were significantly down-regulated and 16 miRNAs were up-regulated when comparing sows with LLS and SLS, respectively. We further characterized the role of miR-183 which was one of the most up-regulated miRNAs. CCK-8, EdU incorporation and western blotting assays demonstrated that miR-183 promoted the proliferation of granulosa cells (GCs) in pig ovaries. Moreover, miR-183 inhibited the synthesis of estradiol in GCs and promoted the synthesis of progesterone. These results will help in gaining understanding of the role of miRNAs in regulating porcine litter size.

窝产活仔数是一项重要的繁殖性状，也是衡量猪场生产水平与经济效益的核心指标之一。卵巢是母猪重要的生殖器官，在每个发情周期中都会发生一系列生物学过程。卵巢内由编码RNA与非编码RNA构成的复杂转录调控网络，可精准调控母猪的繁殖性能。然而，影响母猪窝产仔数的分子调控机制仍未完全阐明。本研究针对平均窝产仔数较低（smaller than average litter sizes, SLS）与较高（larger than average litter sizes, LLS）的母猪，对其卵巢组织中的微小RNA（microRNAs, miRNAs）表达谱进行了分析。共计鉴定出411种miRNAs，相较于SLS组母猪，LLS组母猪的卵巢组织中有17种miRNAs显著下调、16种miRNAs显著上调。本研究进一步对上调最为显著的miRNAs之一——miR-183的生物学功能进行了解析。通过CCK-8细胞增殖实验、EdU掺入实验与蛋白质印迹（western blotting）实验证实，miR-183可促进猪卵巢颗粒细胞（granulosa cells, GCs）的增殖。此外，miR-183可抑制GCs中雌二醇的合成，并促进孕酮的生成。本研究结果有助于深入解析miRNAs在调控猪窝产仔数过程中的作用机制。