Transcriptome and Functional Analysis Uncover the Role of ADCY5 in Bovine Adipogenesis

Adipose deposition is genetically regulated and acts as a core determinant of meat quality in livestock. Therefore, exploring the gene regulatory mechanisms underlying adipose deposition is essential to advance the research on adipose tissue development and molecular breeding in livestock. To clarify the molecular basis of the superior meat quality of Pinan (PN) cattle, high-throughput RNA sequencing was performed to screen the key genes regulating adipose deposition in PN, with Nanyang (NY) cattle serving as the control (n = 3 per breed). A total of 265 differentially expressed genes (DEGs) were identified in the adipose tissue of PN cattle relative to NY cattle, comprising 135 upregulated and 130 downregulated genes. GO and KEGG enrichment analysis revealed that these DEGs were primarily enriched in lipid binding-related functional categories, particularly lipid antigen binding and exogenous lipid antigen binding, as well as enzymatic functions such as protein xylosyltransferase activity. Meanwhile, RT-qPCR confirmed significant differential expression of WNT16, IGFBP2, PEMT, ADCY5, and IDH3B in adipose tissue between PN and NY cattle, consistent with the RNA-seq data. Moreover, functional validation experiments, including RT-qPCR, CCK-8, EdU, and Oil Red O staining, revealed that RNA interference (RNAi)-mediated ADCY5 knockdown markedly promoted adipocyte proliferation, while significantly inhibiting adipocyte differentiation and lipid droplet formation. Collectively, the present study indicates that the identified DEGs are potentially involved in the regulation of bovine adipose tissue development. Notably, ADCY5 exhibits a crucial regulatory effect on cattle adipose deposition; however, the precise molecular mechanism remains to be further elucidated in future studies.