The purpose of this study was to explore and verify genes that regulate the reproductive traits of Tibetan pigs at the mRNA level. The ovarian tissues of Tibetan pigs (TPs) and Yorkshire pigs (YPs) were selected as research objects, and cDNA libraries of the ovarian tissue transcripts of Tibetan pigs and Yorkshire pigs were successfully constructed by the RNA-Seq technique. A total of 651 differentially expressed genes (DEGs) were screened, including 414 up-regulated genes and 237 down-regulated genes. Through GO and KEGG enrichment analysis, it was found that these differentially expressed genes were significantly enriched in cell process, reproductive process, reproduction, cell proliferation, binding, and catalytic activity, as well as oxidative phosphorylation, endocrine resistance, thyroid hormone, Notch, and other signal transduction pathways. Genes significantly enriched in pathways closely related to reproductive regulation were analyzed and selected, and the AR, CYP11A1, CYP17A1, INHBA, ARRB2, EGFR, ETS1, HSD17B1, IGF1R, MIF, SCARB1, and SMAD4 genes were identified as important candidate genes. Twelve differentially expressed genes related to reproduction were verified by RT-qPCR. The results showed that the expression of the AR, CYP17A1, EGFR, ETS1, IGF1R, and SMAD4 genes was significantly higher in Tibetan pigs than in Yorkshire pigs, while the expression of the CYP11A1, INHBA, ARRB2, HSD17B, MIF, and SCARB1 genes in Tibetan pigs was significantly lower than in Yorkshire pigs. The purpose of this study is to provide a theoretical basis for exploring the molecular mechanism of reproductive trait effect genes and the application of molecular breeding in Tibetan pigs.

Background/Objectives: The aim of this study was to explore the effects of diets with different protein levels on the metabolite composition and metabolic pathways of the longest dorsal muscle of Tibetan pigs, in order to provide a metabolic basis for optimizing the nutritional regulation strategy of Tibetan pigs. Methods: A total of 32 healthy 180-day-old depopulated male Tibetan pigs were randomly divided into four groups and fed diets with protein levels of 10%, 12%, 14%, and 16%, respectively, with a feeding cycle of 8 weeks. The longest dorsal muscle samples were collected, and their metabolic profiles were systematically analyzed by LC-MS non-targeted metabolomics. Results: The TIC plots of the quality control samples were highly overlapped, indicating a stable instrumental detection process and good consistency of sample processing. Principal component analysis and orthogonal partial least squares discriminant analysis revealed significant metabolic differences between groups with different protein levels. A total of multiple differential metabolites was obtained based on VIP value and p-value screening, and Venn diagram analysis revealed a total of 11 metabolites among the three comparative groups, suggesting that they may have key roles in the protein regulation process. Volcano plots further clarified the number and trend of significantly up- and down-regulated metabolites in each group. KEGG pathway enrichment analysis showed that, with the elevation of protein level, the metabolic pathway response showed a tendency of expanding from basal energy metabolism to the complex network of amino acid synthesis, steroidogenesis, endocrine signaling, and detoxification pathways, especially in the high-protein-treated group. Conclusions: The study showed that different protein intake levels could significantly regulate the metabolites and key metabolic pathways in the longest muscle of Tibetan pigs, which provided theoretical support for the scientific formulation of a protein supply program to optimize the quality and growth performance of Tibetan pork.