Intramuscular fat (IMF) is closely related to the tenderness, juiciness, and flavor of beef, and is an important indicator for beef quality assessment internationally. The main components of skeletal intramuscular fat (IMF) are phospholipids and triacylglycerols (TAG), and the final step of TAG biosynthesis is catalyzed by diacylglycerol acyltransferase 2 (DGAT2). To explore the effect of DGAT2 on the differentiation of bovine muscle satellite cells (BSCs) and its role in the signaling pathway related to lipid metabolism, the adenovirus overexpression and interference vector of the DGAT2 gene was constructed in this study, and the overexpression adenovirus Ad-DGAT2 and interfering adenovirus sh-DGAT2 were used to infect BSCs. Overexpression of DGAT2 resulted in a significant increase in the contents of TAG and ADP, and the mRNA and protein expression levels of PPARγ, C/EBPα, and SREBF1 (p < 0.05). Interfering with the expression of DGAT2 reduced the intracellular TAG content and lipid droplet accumulation. Furthermore, the mRNA and protein expression levels of PPARγ, C/EBPα, and SREBF1 (p < 0.05) were significantly downregulated. Transcriptome sequencing showed that a total of 598 differentially expressed genes (DEGs) were screened in BSCs infected with Ad-DGAT2, and these DEGs included 292 upregulated genes and 306 downregulated genes. A total of 49 DEGs were screened in BSCs infected with sh-DGAT2, and these DEGs included 25 upregulated and 24 downregulated genes. KEGG enrichment analysis showed that the DEGs, after overexpression of DGAT2, were mainly enriched in the PPAR signaling pathway, and the fat digestion and absorption, glycerophospholipid metabolism, fatty acid biosynthesis, and AMPK signaling pathways. The DEGs obtained after interfering with DGAT2 were mainly enriched in the metabolic pathways, such as the PPAR signaling pathway and PI3K/AKT signaling pathway. In summary, our study demonstrated that the lipid droplet formation, TAG accumulation, and adipogenic gene expression in BSCs overexpressing DGAT2 were higher than those in the control cells. These results highlight the important role of DGAT2 in regulating BSCs during adipogenic transdifferentiation and underscore the complexity of intramuscular adipogenesis.

Poor quality straw can be made more digestible and palatable through delignification using white rot fungi as a biological treatment in SSF. The decomposition of organic matter by white rot fungi is improved when a carbon source is added. Reducing the fermentation cycle can also help retain more nutrients in straw feed. To increase rumen digestibility and nutrient utilization, corn straw and rice straw were subjected to SSF with white rot fungi (Phanerochaete chrysosporium) for 21 days. The type of carbon source (glucose, sucrose, molasses, or soluble starch) was optimized, and the nutrient composition and in vitro fermentation parameters of the fermented straw were assessed. In the fermented corn straw and rice straw supplemented with different carbon sources, the results showed a decrease in lignin content, dry matter, cellulose, and hemicellulose loss, and an increase in crude protein content after 21 days. Total volatile fatty acid and ammonium nitrogen concentrations increased significantly (p < 0.01) during in vitro fermentation. Overall, the most enhanced nutritional values for corn straw and rice straw were observed after 14 days of SSF in the groups using molasses or glucose as a carbon source.

Skeletal muscle satellite cells have the ability to differentiate into various cells under different conditions. This study aimed to investigate the effects of different concentrations of oleic acid (50, 100, and 200 µmol/L) on the process of lipogenic transdifferentiation in Yanbian bovine satellite cells, as well as its molecular regulatory mechanism. After inducing differentiation with oleic acid for 96 h, it was observed that the addition of oleic acid resulted in the formation of lipid droplets in the bovine satellite cells, and the triglyceride content showed a dose-dependent relationship with the concentration of OA. qPCR results demonstrated a significant downregulation of myogenesis-related factors (Pax3 and MyoD) and upregulation of lipogenesis-related factors (C/EBP-β and PPARγ) (p < 0.05). Fatty acid metabolism-related factors, SCD and PLIN2, were also significantly upregulated (p < 0.05). These finding were consistent with the results obtained from Western blotting. Transcriptome sequencing analysis identified 278 differentially expressed genes between the control group and the groups treated with OA. KEGG enrichment analysis showed that differentially expressed genes were mainly concentrated in the adenosine monophosphate-activated protein kinase signaling pathway and fatty acid metabolic pathway. Our study presents that the OA induction of Yanbian bovine skeletal muscle satellite cells can promote cellular lipid transdifferentiation and reveals the potential genes and pathways related to OA induction of these satellite cells.

Deoxynivalenol (DON) is a prevalent trichothecene mycotoxin with well-recognized intestinal toxicity, yet the molecular and cellular remodeling patterns associated with DON-related intestinal barrier dysfunction remain incompletely understood. Here, an integrative computational framework combining network toxicology, bulk transcriptomics, WGCNA, machine learning, immune infiltration analysis, molecular docking, single-cell transcriptomics, CellChat, and in silico gene perturbation was applied. A total of 1119 distinct genes were obtained from the traceable retained intestinal disease- and barrier-related lists from CTD, GeneCards, OMIM, and PharmGKB. Intersecting this set with differentially expressed genes and genes in the disease-associated WGCNA module yielded 23 database- and transcriptome-supported intestinal disease/barrier candidate genes, which were subsequently evaluated for their potential relevance to DON-related intestinal barrier dysfunction. Machine learning further prioritized six hub genes: SLC6A14, TIMP1, CXCL1, S100A11, LCN2, and NOS2. Single-cell mapping highlighted fibroblasts as an important disease-associated stromal compartment, while CellChat analysis revealed enhanced CXCL signaling in disease samples. CXCL1 showed prominent expression in disease-associated fibroblasts, and its in silico knockout perturbed genes related to inflammatory remodeling, oxidative stress, extracellular matrix organization, and stromal activation. Fibroblast subclustering further identified disease-enriched CXCL-associated inflammatory and stress-response states. Overall, these findings identify CXCL1-associated fibroblast inflammatory remodeling as a candidate stromal context potentially relevant to DON-related intestinal barrier dysfunction, rather than as a DON-specific mechanism, and provide a hypothesis-generating basis for future experimental validation.