MiR-25, a member of the miR-106b-25 cluster, has been reported as playing an important role in many biological processes by numerous studies, while the role of miR-25 in metabolism and its transcriptional regulation mechanism remain unclear. In this study, gain-of-function and loss-of-function assays demonstrated that miR-25-3p positively regulated the metabolism of C2C12 cells by attenuating phosphoinositide 3-kinase (PI3K) gene expression and triglyceride (TG) content, and enhancing the content of adenosine triphosphate (ATP) and reactive oxygen species (ROS). Furthermore, the results from bioinformatics analysis, dual luciferase assay, site-directed mutagenesis, qRT-PCR, and Western blotting demonstrated that miR-25-3p directly targeted the AKT serine/threonine kinase 1 (Akt1) 3′ untranslated region (3′UTR). The core promoter of miR-25-3p was identified, and the transcription factor activator protein-2α (AP-2α) significantly increased the expression of mature miR-25-3p by binding to its core promoter in vivo, as indicated by the chromatin immunoprecipitation (ChIP) assay, and AP-2α binding also downregulated the expression of Akt1. Taken together, our findings suggest that miR-25-3p, positively regulated by the transcription factor AP-2α, enhances C2C12 cell metabolism by targeting the Akt1 gene.

Amino acids are critical for mammalian target of rapamycin complex 1 (mTORC1) activation on the lysosomal surface. Amino acid transporters SLC38A9 and SLC36A1 are the members of the lysosomal amino acid sensing machinery that activates mTORC1. The current study aims to clarify the interaction of SLC38A9 and SLC36A1. Here, we discovered that leucine increased expressions of SLC38A9 and SLC36A1, leading to mTORC1 activation. SLC38A9 interacted with SLC36A1 and they enhanced each other’s expression levels and locations on the lysosomal surface. Additionally, the interacting proteins of SLC38A9 in C2C12 cells were identified to participate in amino acid sensing mechanism, mTORC1 signaling pathway, and protein synthesis, which provided a resource for future investigations of skeletal muscle mass.

This study investigated the effect of different concentrations of ferulic acid (FA) on the quality of goat semen preserved at 17 °C. First, semen was collected from three black-headed goat bucks using an artificial vagina. Then, the mixed semen was diluted with basal dilutions containing different concentrations of FA (0, 25, 50, 100, and 200 μmol/L) and stored at 17 °C. Sperm total motility, plasma membrane integrity, acrosome integrity, reactive oxygen species (ROS) levels, malondialdehyde (MDA) content, and total antioxidant capacity (T-AOC) were measured during semen storage. The results showed that sperm total motility, plasma membrane integrity, and acrosome integrity were significantly improved in the 50 μmol/L FA group compared with the control group (0 μmol/L) on days 1–5, and the level of T-AOC significantly increased, while the contents of ROS and MDA significantly reduced. Meanwhile, the goats’ conception rate showed that supplementing semen with 50 μmol/L FA preserved at 17 °C for 3 days had no significant effect on fertility. Taken together, our findings suggest that adding 50 μmol/L FA in dilution at 17 °C can improve goat bucks’ semen quality.

Intramuscular fat (IMF) deposition serves as a critical determinant of beef quality, the underlying molecular and metabolic characteristics remain incompletely elucidated. Here, we integrated transcriptomic sequencing with untargeted profiling to investigate molecular features associated with IMF deposition in two cattle breeds. Transcriptomic analysis identified multiple differentially expressed genes (DEGs) involved in lipid metabolism, including SCD, FASN, and ELOVL6. Untargeted metabolomic profiling revealed a series of differentially accumulated metabolites (DEMs) predominantly associated with fatty acid and coenzyme metabolism, such as arachidonyl-CoA, trans-oct-2-enoyl-CoA, oleoylethanolamide. Integrated analysis demonstrated significant correlations between subsets of differentially expressed genes and metabolites within lipid metabolism-related pathways, indicating coordinated molecular and metabolic alterations during IMF deposition. Based on these findings, representative genes exhibiting strong correlations with differential metabolites were further validated at the cellular level, providing experimental support for the integrated multi-omics findings. This study delineates transcriptomic and metabolomic signatures of bovine IMF, providing a valuable data resource for understanding its metabolic basis.

Alternative splicing (AS) plays a crucial role in the post-transcriptional regulation of gene expression, influencing skeletal muscle growth and development. However, research into transcriptomic landscape of AS and its key isoforms associated with skeletal muscle in goats is comparatively limited compared with other livestock species such as pigs. In this study, longissimus dorsi muscles from 4 Macheng black goats and 4 Boer goats were used to perform Oxford Nanopore Technologies full-length sequencing and Illumina RNA-seq. A total of 91,874 unique full-length non-chimeric sequences and 10,955 novel isoforms were identified. Subsequently, we detected 13,866 AS events and 1702 novel long non-coding RNAs (lncRNAs), with exon skipping (4024, 29.02 %) being the most prevalent AS event. In addition, a total of 2267 differentially expressed isoforms (DEIs) were identified between Macheng black and Boer goats. Among these DEIs, 1301 isoforms were up-regulated and 966 were down-regulated in Macheng black goats. Functional enrichment analyses revealed that these DEIs were predominantly associated with pathways related to skeletal muscle development, cellular metabolic processes, and genetic information processing. Notably, we identified LUC7L-201 as an important isoform that negatively regulates cell proliferation and differentiation in goat primary myoblasts, as demonstrated by overexpression experiments. Overall, this study enhances our understanding of the transcriptomic diversity underlying skeletal muscle growth and development in goats, providing valuable insights for future research and potential applications in livestock management.

The developmental process of skeletal muscle involves a wide variety of regulatory factors. However, little has been reported regarding the function and mechanisms of enhancer regulation in buffalo skeletal muscle growth and development. In this study, we discovered an enhancer that affects the buffalo skeletal muscle growth and development, which we named Enh67. Experimental results from CCK-8, EdU, qPCR, and Western blot assays indicated that Enh67 inhibits the proliferation of buffalo muscle stem cells. Immunofluorescence staining, qPCR, and Western blot results showed that Enh67 promotes the differentiation of buffalo muscle stem cells. Finally, we determined through 3C and qPCR assays that Enh67 targets CEP85L. Our findings not only enrich the regulatory factors involved in buffalo skeletal muscle growth and development but also provide potential target candidates for improving meat production and treating muscle development-related diseases in livestock.