Determination of the Heterogeneity of Intramuscular Fat and Visceral Adipose Tissue From Dezhou Donkey by Lipidomics and Transcriptomics Profiling

Abstract

Intramuscular fat (IMF) and visceral adipose tissue (VAT) are both lipids, but have significantly different deposition processes. Furthermore, the heterogeneity of lipid molecular characteristics and mechanisms is unclear. Accordingly, this study used non-targeted lipidomics and transcriptomics to analyze the lipid profiles and metabolism of longissimus dorsi muscle (LDM) and VAT from donkeys. A total of 1,146 and 1,134 lipids belonging to 18 subclasses were identified in LDM and VAT, respectively, with LDM having higher glycerophospholipid (GP) and lower glycerolipid (GL) contents. Polyunsaturated fatty acids (PUFAs) were distributed preferentially at the sn-1 positions in triglycerides (TGs), and sn-2 positions in phosphatidylcholine (PC) and phosphatidylethanolamine (PE). The percentage PUFA content in TGs was significantly lower in LDM than in VAT, while the opposite trend was observed for PUFAs in PC and PE. A total of 110 different lipid molecules (72 downregulated and 38 upregulated) were identified in LDM compared with VAT, of which 11 were considered potential lipid markers. These different lipids were involved in 17 metabolic pathways, including GL and GP metabolisms. Of the 578 differentially expressed genes screened, 311 were downregulated and 267 were upregulated in LDM compared with VAT. Enriched ontology analysis of the differentially expressed genes mainly involved sphingolipid signaling pathways, and GP, GL, and sphingolipid metabolisms. Overall, lipidomics and transcriptomics indicated differences in lipid profiles and metabolism in LDM and VAT, providing new perspectives for the study of heterogeneity in IMF and VAT.

Comparative Lipid Profile Analysis of Hermetia illucens Larvae Fed Food Waste at Different Days of Age Using an LC-MS-Based Lipidomics Approach

“…In the present study, the OPLS-DA model was robust, and overfitting did not occur because all Q 2 points were lower than the rightmost original Q 2 point, and the Q 2 intercept values were in the range of (0, −0.46) in ion mode ( Li et al 2021c ). To differentiate the biomarkers of lipid molecules in larvae of different ages, the lipidomic data were analyzed by one-way ANOVA.…”

Genome-Wide Expression Profiling and Networking Reveals an Imperative Role of IMF-Associated Novel CircRNAs as ceRNA in Pigs

“…Several studies have suggested that lipid oxidation contributes to the development of a pleasant aroma [ 2 , 6 , 11 ]. The literature shows that phospholipids are essential in the development of lipid oxidation, and lean meat is more susceptible to oxidation than fatty meat due to low marbling [ 12 ]. In the Lu et al (2017) study on pigs, the authors determined that higher IMF content in fat-type pigs might be due to an increased need for ECI1-associated lipogenesis in the longissimus dorsi muscles and eventually affect meat quality [ 13 , 14 ].…”

“…It has been revealed in previous studies that the amount of intramuscular fat content in any animal depends on various factors, including genetic makeup, animal breed, nutritional value, weight, age, etc. [ 12 , 13 , 14 , 15 ]. The Laiwu pig (L_JN), an exceptional kind of fatty pig from North China, is famous for its excellent meat quality due to its higher water-retaining capability, bright red color, and tenderness [ 16 ]; it is considered the best animal model to study the mechanisms of high IMF deposition due to high IMF content (11.6%) [ 17 , 18 ].…”

Comparative transcriptome analysis of longissimus dorsi tissues with different intramuscular fat contents from Guangling donkeys

“…Compared with VAT, 267 genes were upregulated and 311 genes were downregulated in the longissimus thoracis . KEGG enrichment analysis revealed that glycerolipid and glycerophospholipid metabolism are key metabolic pathways regulating lipid deposition [ 8 ]. In another study, to compare IMF gene expression patterns, differential expression analysis was performed on the coexpressed mRNAs and the differentially expressed mRNAs in the muscle of Xinyang buffalo and Nanyang cattle.…”