Variation in Bile Acid Synthesis Capacity: A Key Factor in Differentiating Lipid Deposition Patterns in Goldfish Breeds

In our previous study, we observed distinct lipid deposition pattern between Crane-top red goldfish (HDH) and Pearl-scale goldfish (PS), yet the regulatory mechanisms remained unclear. In this study, a comprehensive comparison between HDH and PS was conducted to elucidate the mechanisms driving this difference. Our findings revealed that the hepatopancreas lipid content, as well as the levels of triglyceride and total cholesterol, were significantly higher in HDH than in PS. Conversely, the total bile acid level was significantly higher in PS than in HDH. Transcriptome and proteome analysis identified 3174 differentially expressed genes (DEGs) and 816 differentially expressed proteins (DEPs) between HDH and PS, respectively, which were primarily enriched in pathways associated with PPAR signaling, primary bile acid biosynthesis, steroid hormone biosynthesis, Taurine metabolism, and carbohydrate digestion and absorption. Notably, DEGs and DEPs related to bile acid synthesis were found to play a key role in the observed difference between HDH and PS. Specifically, the CYP27A1 gene and EBP, MSMO1, CYP7B1, and HSD3B7 proteins were up-regulated in PS goldfish, indicating an enhanced bile acid synthesis capacity. Additionally, the abundance of Cetobacterium, which is closely associated with host lipid deposition, was significantly higher in PS intestine than in HDH. To unravel the mechanisms underlying the differences in lipid deposition patterns between Crane-top red goldfish (HDH) and Pearl-scale goldfish (PS), the hepatopancreas of HDH and PS was analyzed transcriptomically.