Background
Meat quality in yak is influenced by the fluctuation of nutritional composition in different grazing seasons on the Qinghai-Tibetan Plateau. However, the molecular mechanism underlying in yak meat remains unknown. Therefore, this study aimed to investigate the seasonal dynamics of meat quality in yak by transcriptomics and metabolomics techniques. Twelve healthy female yaks with a similar weight were divided into two groups, including the warm season group (WS) and cold season group (CS). After slaughter, samples of
longissimus lumborum
were collected and subjected to transcriptomics and metabolomics to explore the effects of different seasons on meat quality.
Results
Yak in the WS group had higher contents of n-3 Polyunsaturated fatty acid (PUFA), n-6 PUFA, threonine, and valine compared to the CS group, but the pH
45min
and b* values were lower. A total of 75 differentially expressed metabolites in the
longissimus lumborum
muscle were identified, with 23 metabolites upregulated and 52 metabolites downregulated in the WS group. These metabolites were mainly enriched in the pathway of glycine, serine and threonine metabolism, tryptophan metabolism, and carbohydrate digestion and absorption. In comparison, the WS group exhibited 262 upregulated genes in the
longissimus lumborum
muscle and 81 downregulated genes relatives to the CS group, which were enriched in the fat deposition of TGF-beta, ECM-receptor interaction, MAPK, and PPAR signaling pathway.
Conclusions
Among these, downregulated genes
NPNT
,
GADL1
,
SESN3
, and
CPXM1
were associated with lipid metabolism and fat deposition in grazing yaks. It was found that
DDC
,
DHTKD1
,
CCBL1
,
GCDH
, and
AOC1
involved in the tryptophan metabolism played an important role in the regulation of energy metabolism in yak.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12864-024-11093-5.