RNA-Seq revealed the effect of adding different proportions of wheat diet on fat metabolism of Tibetan lamb.

The objective of this study was to evaluate the effect of the level of wheat substitution for corn on the fat metabolism of Tibetan lamb. A total of 90 Tibetan lambs [body weight (BW) of 19.78 ± 2.45 kg] were arranged with three substitution levels of wheat: WC (100 % corn), WL (10 % wheat substitution for corn), and WH (15 % wheat substitution for corn) on a dry matter basis. After the experiment, cry section technology was used to scrutinize the subcutaneous adipose tissue morphology, and genes related to fat metabolism were excavated using high-throughput sequencing technology. According to the study results, fat diameter and fat biovolume of the WL and WH groups were less than the WC group. A total of 506 differentially expressed genes (DEGs) were identified by RNA sequencing (RNA-Seq) technology. Compared with the WC group, 66 DEGs were upregulated and 59 DEGs were downregulated in the WL group, and 179 DEGs were upregulated and 269 DEGs were downregulated in the WH group. The top 20 DEGs were analyzed by Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway, indicating significant differences in the fat metabolism pathway. Five DEGs were randomly screened for quantitative reverse transcription-polymerase chain reaction (qRT-PCR) verification, and the results were consistent with the RNA-Seq results, which proved the accuracy of sequencing. In summary, with the increase in the proportion of supplemental wheat, the fat cells became smaller, and the genes related to fat decomposition were significantly upregulated.