Comprehensive Analysis of Transcriptome and Metabolome Reveals Regulatory Mechanism of Intramuscular Fat Content in Beef Cattle

The intramuscular fat (IMF) content
of beef determined the meat
quality, and the market value of beef varies with different breeds.
To provide some new approaches for improving meat quality and cattle
breed improvement, 24-month-old Qinchuan cattle (Q, n = 6), Nanyang cattle (N, n = 6), and Japanese black
cattle (J, n = 6) were selected. IMF content of the
J group (16.92 ± 1.08%) is remarkably higher than that of indigenous
Chinese cattle (Q, 13.38 ± 1.08%, and N, 12.35 ± 1.22%).
Monounsaturated fatty acids and polyunsaturated fatty acids in the
J group are higher than the Q and creatine, lysine, and glutamine
are the three most abundant amino acids in beef, which contribute
to the flavor formation. Similarly, IMF content-related genes were
enriched in four vital KEGG pathways, including fatty acid metabolism,
biosynthesis of unsaturated fatty acids, fatty acid elongation, and
insulin resistance. Moreover, weighted genes coexpression network
analysis (WGCNA) revealed that ITGB1 is the critical
gene associated with the IMF content. This study compares transcriptome
and metabolome of local and high-IMF cattle breeds, providing data
for native cattle breeding and improvement of beef quality.