Interpreting Ovarian Dynamics: Transcriptomic and Metabolomic Insights into Porcine Gonadal Development and Gestation

The ovary is the central organ of the reproductive system, responsible for producing oocytes, synthesizing and secreting steroid hormones. The healthy development and regular cyclical changes of the ovaries are crucial for regulating the reproductive process. This study conducted high-throughput RNA-seq, miRNA-seq, and non targeted metabolite analysis on the ovarian tissues of Chenghua sows at four stages: day 3 after birth (D3), puberty (Pub), one year after birth (Y1), and day 105 of pregnancy (Pre). By comparing the expression changes of mRNA, miRNA, and metabolites during infancy, adolescence, sexual maturity, and pregnancy, multiple key genes and metabolites related to ovarian development and pregnancy maintenance were identified. Research has found that several genes rich in steroid synthesis pathways, such as CYP11A1, HSD3B1, HSD17B1, and SCARB1, are closely related to ovarian development. Joint analysis was also conducted on differential metabolites in this pathway. In addition, the study also identified key genes that maintain pregnancy, such as LUM, FN1, PLAUR, and SELP. A differentiated miRNA targeted mRNA interaction network has been constructed. Clarifying the molecular regulatory mechanisms of ovarian development and pregnancy in sows may provide new theoretical insights for improving sow fertility. Overall design: In this study, ovarian tissues were collected at four time points: on postnatal day 3 (D3), at postnatal day 120 just entering puberty (Pub), 1st year (Y1) of birth during sexual maturity, and 105th day of pregnancy (Pre). These sows were obtained from the Chengdu Livestock and Poultry Genetic Resources Protection Center (Sichuan, China). Every Chenghua sows was in good health with no history of reproductive diseases. They were kept under the same environmental conditions with the comparable level of nutrition. Three healthy sows were selected from each age groups, labeled as D3-1, D3-2, D3-3, and so on, and their ovaries were collected for this study. The ovary tissue was first washed with 1X PBS and cutted into 3–5 cm2 fragments and immediately snap-frozen in liquid nitrogen for total RNA extraction.