Yang Lixian, Cui Ran, Li Zhen, Xue Mingming, Chan Shuheng, Xue Pengxiang, Yang Xiaoyang, Zhang Longmiao, Lv Fenghua, Fang Meiying
Department of Animal Genetics and Breeding, National Engineering Laboratory for Animal Breeding, MOA Laboratory of Animal Genetics and Breeding, Beijing Key Laboratory for Animal Genetic Improvement, State Key Laboratory of Animal Biotech Breeding, Frontiers Science Center for Molecular Design Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Int J Mol Sci. 2025 Jun 27;26(13):6224. doi: 10.3390/ijms26136224.
Tan sheep outperform Dorper sheep in meat-quality traits, including muscle fiber characteristics and fatty acid composition, while Dorper sheep excel in carcass weight. However, the molecular mechanisms underlying these breed-specific traits, especially gut microbiota-bile acid (BA) interactions, remain poorly understood. As host-microbiota co-metabolites, BAs are converted by colonic microbiota via bile salt hydrolase (BSH) and dehydroxylases into secondary BAs, which activate BA receptors to regulate host lipid and glucose metabolism. This study analyzed colonic BA profiles in 8-month-old Tan and Dorper sheep, integrating microbiome and longissimus dorsi muscle transcriptome data to investigate the gut-muscle axis in meat-quality and carcass trait regulation. Results showed that Tan sheep had 1.6-fold higher secondary BA deoxycholic acid (DHCA) levels than Dorper sheep ( < 0.05), whereas Dorper sheep accumulated conjugated primary BAs glycocholic acid (GCA) and tauro-α-muricholic acid ( < 0.05). Tan sheep exhibited downregulated hepatic BA synthesis genes, including cholesterol 7α-hydroxylase () and 27-hydroxylase (), alongside upregulated transport genes such as bile salt export pump (), sodium taurocholate cotransporting polypeptide (), and ATP-binding cassette subfamily B member 4 (), with elevated gut BSH activity ( < 0.05). DHCA was strongly correlated with , , and , muscle fiber density, diameter, and linoleic acid (C18:2n6t) (|r| > 0.5, < 0.05). In contrast, GCA was significantly associated with , , , carcass weight, and net meat weight (|r| > 0.5, < 0.05). In conclusion, breed-specific colonic BA profiles were shaped by host-microbiota interactions, with DHCA potentially promoting meat quality in Tan sheep via regulation of muscle fiber development and fatty acid deposition, and GCA influencing carcass traits in Dorper sheep. This study provides novel insights into the gut microbiota-bile acid axis in modulating ruminant phenotypic traits.
滩羊在肉质性状方面表现优于杜泊羊，包括肌肉纤维特征和脂肪酸组成，而杜泊羊在胴体重量方面表现出色。然而，这些品种特异性性状背后的分子机制，尤其是肠道微生物群与胆汁酸（BA）的相互作用，仍知之甚少。作为宿主-微生物群的共同代谢产物，胆汁酸通过结肠微生物群中的胆汁盐水解酶（BSH）和脱羟基酶转化为次级胆汁酸，后者激活胆汁酸受体以调节宿主的脂质和葡萄糖代谢。本研究分析了8月龄滩羊和杜泊羊的结肠胆汁酸谱，整合微生物组和背最长肌转录组数据，以研究肉质和胴体性状调控中的肠-肌轴。结果表明，滩羊的次级胆汁酸脱氧胆酸（DHCA）水平比杜泊羊高1.6倍（P<0.05），而杜泊羊积累了共轭初级胆汁酸甘氨胆酸（GCA）和牛磺-α-鼠胆酸（P<0.05）。滩羊肝脏胆汁酸合成基因，包括胆固醇7α-羟化酶（CYP7A1）和27-羟化酶（CYP27A1）表达下调，同时转运基因如胆盐输出泵（BSEP）、牛磺胆酸钠共转运多肽（NTCP）和ATP结合盒亚家族B成员4（ABCB4）表达上调，肠道BSH活性升高（P<0.05）。DHCA与CYP7A1、CYP27A1以及肌肉纤维密度、直径和亚油酸（C18:2n6t）显著相关（|r|>0.5，P<0.05）。相反，GCA与CYP7A1、CYP27A1、BSEP、胴体重量和净肉重显著相关（|r|>0.5，P<0.05）。总之，品种特异性结肠胆汁酸谱由宿主-微生物群相互作用形成，DHCA可能通过调节肌肉纤维发育和脂肪酸沉积促进滩羊肉质，而GCA影响杜泊羊的胴体性状。本研究为肠道微生物群-胆汁酸轴调节反刍动物表型性状提供了新的见解。
