The beef cattle industry has seen rapid expansion, necessitating the optimization of slaughter traits for enhanced economic benefits. Copy number variation (CNV) has emerged as a pivotal molecular marker in marker-assisted selection (MAS) for genetic improvement in livestock. In this study, we focused on CNVs within the HIF1A and HIF2A genes, which play crucial roles in hypoxic signaling and energy metabolism. Four CNVs were identified in the bovine HIF1A gene and three in HIF2A using the AAOD database. In Gaoqing Black cattle (GQB), the distribution of CNVs for both genes was investigated, revealing predominantly median copy numbers. Association analysis showed a significant relation between CNVs in HIF1A and carcass traits such as cervical vertebrae (CNV1), initial weight and beef diaphragm (CNV2), slaughter weight and chuck (CNV3), and femur and chuck (CNV4) (p < 0.05 or p < 0.01). Similarly, CNVs in HIF2A are associated with traits like beef diaphragm, beef knuckle bone, and beef tendon (CNV1), longissimus dorsi width and beef diaphragm (CNV2), and slaughter weight and limb weights (CNV3) (p < 0.05 or p < 0.01). These findings provide insights into the potential influence of CNVs in HIF1A and HIF2A on carcass traits in Gaoqing Black cattle, offering a theoretical basis for genetic improvement in beef cattle breeding.

Ferroptosis of mesenchymal stem cells (MSCs) is a critical bottleneck restricting the efficiency of ruminant biological breeding. Phloretin, a natural bioactive polyphenol, exhibits potential ferroptosis-inhibitory activity. However, the regulatory effects and underlying mechanisms of phloretin on ruminant MSCs remain poorly understood. This study aimed to investigate the effects of phloretin on ferroptosis and elucidate its underlying molecular mechanisms. Herein, we isolated and cultured adipose-derived mesenchymal stem cells (AD-MSCs) from adipose tissue of a 9-day-old Leizhou goat and established a ferroptosis model in these cells using RSL3. We detected cell viability, proliferation, migration, ferroptosis-related indexes and key protein expression. The results showed that phloretin (25 and 50 μM) dose-dependently inhibited ferroptosis in goat AD-MSCs, reducing intracellular ferrous ion (Fe²⁺), reactive oxygen species (ROS) and lipid peroxidation levels, restoring glutathione content, and ameliorating mitochondrial structural damage. Mechanistically, phloretin exerted its anti-ferroptosis effects through direct antioxidant activity, activation of the Nrf2/HO-1/GPX4 signaling pathway and Fe²⁺ chelation. Nrf2 and GPX4 were key targets in this process. These results provide preliminary in vitro evidence and a theoretical basis for the potential application of phloretin in future research related to meat goat production and ruminant breeding.

Treatment for acute liver failure (ALF) is constrained by shortages of liver transplant donors and immune rejection. Porcine bone marrow mesenchymal stem cells (pBMSCs) demonstrate clinical potential in xenotransplantation due to their abundant availability, low immunogenicity, and strong proliferative activity. This study is the first to investigate the reparative effects and mechanisms of pBMSCs derived from Luopan Mountain pigs in a D-galactosamine (D-GalN)-induced ALF rat model. The results demonstrated that tail-vein transplantation of pBMSCs significantly improved survival rates in ALF rats; reduced serum ALT, AST, and TBIL levels; enhanced hepatic glycogen metabolism; and mitigated histopathological liver damage. Additionally, pBMSC transplantation upregulated serum HGF, IGF-1, and VEGF levels while inhibiting hepatocyte apoptosis. Mechanistic studies indicate that pBMSCs promote liver function recovery and regeneration by activating the PI3K/Akt/mTOR signaling pathway and suppressing its key negative regulator, PTEN, by regulating the expression of key genes involved in inflammation, fibrosis, proliferation, and apoptosis. This study provides crucial experimental evidence for the use of pBMSCs in treating acute liver failure (ALF) and lays the groundwork for its clinical translation in the field of xenotransplantation.