(1) Background: Mengshan cattle from the Yimeng mountainous region in China stand out as a unique genetic resource, known for their adaptive traits and environmental resilience. However, these cattle are currently endangered and comprehensive genomic characterization remains largely unexplored. This study aims to address this gap by investigating the genomic features and selection signals in Mengshan cattle. (2) Methods: Utilizing whole-genome resequencing data from 122 cattle, including 37 newly sequenced Mengshan cattle, we investigated population structure, genetic diversity, and selection signals. (3) Results: Our analyses revealed that current Mengshan cattle primarily exhibit European taurine cattle ancestry, with distinct genetic characteristics indicative of adaptive traits. We identified candidate genes associated with immune response, growth traits, meat quality, and neurodevelopment, shedding light on the genomic features underlying the unique attributes of Mengshan cattle. Enrichment analysis highlighted pathways related to insulin secretion, calcium signaling, and dopamine synapse, further elucidating the genetic basis of their phenotypic traits. (4) Conclusions: Our results provide valuable insights for further research and conservation efforts aimed at preserving this endangered genetic resource. This study enhances the understanding of population genetics and underscores the importance of genomic research in informing genetic resources and conservation initiatives for indigenous cattle breeds.

Necroptosis and dysfunction of ovarian granulosa cells are major contributors to follicular atresia and reduced fertility in cattle, processes that are closely associated with endoplasmic reticulum stress (ERS). Ginseng polysaccharides (GPSs) are known to reduce ER stress, display anti-inflammatory properties, and modulate reproductive function; however, whether GPS can protect against granulosa cell injury and the underlying mechanisms remain unclear. To address this gap, this study aimed to investigate the protective effects of GPS on ERS-induced bovine granulosa cell damage and to elucidate the associated mechanisms. An ERS model was established in bovine granulosa cells using tunicamycin (Tm), and cellular responses were evaluated via flow cytometry, ELISA, and EdU assays. Further, a mouse model was used to validate the protective effects of GPS against Tm-induced ovarian injury. The results showed that 40 μg/mL of GPS significantly alleviated ERS-induced granulosa cell damage, inhibited necroptosis, and mitigated ERS. Moreover, using the PI3K/Akt pathway inhibitor LY294002, we demonstrated that the inhibitor antagonized the effects of GPS, indicating that GPS promotes granulosa cell proliferation and restores estrogen secretion via activating the PI3K/Akt pathway. In vivo experiments further confirmed that GPS effectively attenuates ERS-induced ovarian damage in mice. Collectively, these findings reveal that GPS improves granulosa cell function and ovarian tissue integrity by modulating the ERS network and the PI3K/Akt pathway, yielding a theoretical basis for preventing follicular atresia and enhancing reproductive efficiency in cattle.

Dimethyl sulfoxide (DMSO) is widely utilized in the vitrification of oocytes, but DMSO exhibits concentration-dependent toxicity, which can compromise oocyte developmental potential by disrupting key cellular processes. This study reports the first successful use of cold shock protein B (CspB protein) as a substitute for DMSO in vitrification solutions for oocyte vitrification. Combining dynamics simulations and experimental validation, we demonstrated CspB’s ability to inhibit ice crystallization and recrystallization by stabilizing its position at the ice–water interface and reducing ice formation rates. Recombinant CspB was successfully expressed and shown to bind to the oolemma. In vitrification solutions, CspB (1–2 mg/mL) effectively reduced ice crystal size and enabled a significant reduction or complete replacement of DMSO. This strategy markedly improved the post-thaw survival rates of both mouse and bovine metaphase II (MII) oocytes. Furthermore, oocytes vitrified with an optimized formulation (15% ethylene glycol + 2 mg/mL CspB) exhibited developmental competence (cleavage and blastocyst rates), oxidative stress markers (ROS, GSH), mitochondrial function (membrane potential and content), and apoptosis levels (Caspase-3/9) comparable to those treated with a standard DMSO-containing system. Transcriptomic analysis revealed that CspB’s cryoprotection involves the modulation of the mTOR signaling pathway. This role was functionally confirmed, as activation of mTOR abolished CspB’s beneficial effects, reinstating oxidative damage, mitochondrial dysfunction, and apoptosis. Thus, the CspB protein replaces DMSO with direct ice crystal formation suppression and mTOR-mediated oxidative stress regulation. This study offers a protein-based alternative to conventional permeable cryoprotectants. This approach holds promise for improving reproductive biotechnologies across species.

Meat quality is an important economic trait in beef cattle and is influenced by breed-related metabolic characteristics. Yanbian cattle (YB) are valued for desirable meat quality, whereas Yanhuang cattle (YH), developed using Limousin cattle as the paternal line and Yanbian cattle as the maternal line, exhibit improved growth performance and carcass yield. However, the molecular basis underlying metabolic variation between these two genetically related cattle populations remains unclear. In this study, longissimus thoracis muscle samples from six animals per breed were analyzed using LC-MS/MS-based metabolomics and GC×GC-TOF/MS-based volatile compound profiling, and a subset of three samples per breed from the same cohort was selected for transcriptomic sequencing. A total of 1697 metabolites were detected. Based on the screening criteria of VIP > 1 and p < 0.05, 202 candidate metabolites were identified, among which 11 remained statistically significant after false discovery rate (FDR) correction. Volatile compound profiling detected 1333 and 1516 compounds in YB and YH, respectively, of which 809 were shared. Based on the same screening criteria, 39 candidate volatile compounds were identified, although none remained significant after FDR correction. Transcriptomic analysis identified 360 differentially expressed genes using |log₂FC| > 1 and adjusted p < 0.05, with enrichment mainly observed in pathways associated with carbohydrate metabolism, lipid turnover, and energy utilization. Integrative analyses indicated that amino acid-related metabolites, including phenylpyruvate, 2-aminobenzoic acid, and asparagine, were more closely associated with candidate volatile compounds than metabolites involved in central carbon metabolism. Several genes involved in lipid metabolism, energy metabolism, and muscle structure, including DGAT2, MGLL, CRYAB, CSRP3, AGPAT2, PHKA1, AMPD1, and PGM2L1, were associated with distinct metabolic modules. These findings provide an exploratory view of breed-related metabolic variation and identify candidate molecular features for future validation.