a Key Laboratory for Animal Genetics, Breeding, Reproduction and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu 225009, China.
b Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou 225009, China.
Genome. 2018 Aug;61(8):549-558. doi: 10.1139/gen-2017-0164. Epub 2018 Jun 8.
Intramuscular fat (IMF) content and fatty acid (FA) composition vary significantly across beef cattle breeds, which play an important role in taste and nutritional value. However, the molecular mechanisms underlying these phenotypic differences remain unknown. The present study compared meat quality traits between Yunling cattle and Chinese Simmental cattle. Yunling cattle showed a lower IMF content and proportion of monounsaturated fatty acids (MUFA), as well as higher proportions of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), and short-chain fatty acids (sc-FA) in the longissimus dorsi (LD) muscle than Chinese Simmental cattle. To further identify the candidate genes and pathways responsible for these phenotypic differences, the transcriptome of LD muscle from the two breeds were measured using RNA-seq. A total of 1347 differentially expressed genes were identified. The major metabolic pathways that were differentially modulated were lipolysis and glycometabolism. Yunling cattle showed a higher expression of lipolysis genes (ALDH9A1, ACSL5, ACADM, ACAT2, ACOT2) and a lower expression of genes related to glycometabolism (PGM1, GALM, PGM1, GPI, LDHA). This research identified candidate genes and pathways for IMF content and FA composition in the LD muscle of beef cattle, which may facilitate the design of new selection strategies to improve meat quality.
肌内脂肪（IMF）含量和脂肪酸（FA）组成在不同的肉牛品种间存在显著差异，这些差异对肉质的口感和营养价值有重要影响。然而，这些表型差异的分子机制尚不清楚。本研究比较了云岭牛和中国西门塔尔牛的肉质特性。与中国西门塔尔牛相比，云岭牛的背最长肌 IMF 含量和单不饱和脂肪酸（MUFA）比例较低，饱和脂肪酸（SFA）、多不饱和脂肪酸（PUFA）和短链脂肪酸（sc-FA）比例较高。为了进一步鉴定导致这些表型差异的候选基因和途径，本研究使用 RNA-seq 技术对两个品种的背最长肌转录组进行了测量。共鉴定出 1347 个差异表达基因。差异调控的主要代谢途径是脂肪分解和糖代谢。云岭牛的脂肪分解基因（ALDH9A1、ACSL5、ACADM、ACAT2、ACOT2）表达较高，而糖代谢相关基因（PGM1、GALM、PGM1、GPI、LDHA）表达较低。本研究鉴定了影响肉牛背最长肌 IMF 含量和 FA 组成的候选基因和途径，这可能有助于设计新的选择策略来改善肉质。
