Growth Performance and Meat Quality Evaluations in Three-Way Cross Cattle Developed for the Tibetan Plateau and their Molecular Understanding by Integrative Omics Analysis

Despite of favorable
characteristics of high protein, low fat,
and free-pollution, yak meat has intrinsically poor performance in
tenderness and color, which is ever challenging yak sector. To this
end, a three-way cross system was first developed for high quality
beef of the Tibetan Plateau using Angus cattle (Bos taurus) as terminal sire to mate with 1/2 yak (F1) generated from♂Qaidam
cattle (Bos taurus) × ♀yak (Bos
grunniens). The withers height, chest girth, and body weight
of 1/4 yak (F2) were all great higher than that of yak and 1/2 yak
(P < 0.01), especially at later period, suggesting
the faster growth rate of 1/4 yak. Also the dressing percentage was
much better in 1/4 yak (P < 0.01). Tenderness
and meat color were both significantly improved in 1/4 yak with some
unpleasant sacrifice of PUFAs, such as EPA and DHA, and meat protein,
given the significantly lower shear force and higher L* (P < 0.01). A total of 769 genes, including SREBF1, GHR, and FASN, the widely recognized
causal genes of meat quality, were identified from 11947 differently
expressed genes by the data integration of transcriptome, GWAS and
QTL. These genes were significantly enriched for important pathway
and GO terms, such as insulin signaling pathway, fatty acid biosynthesis,
calcium signaling pathway, metabolic pathway, and cellular response
to stress (P < 0.01). And 12 promising candidates
were exemplified with annotation of H3K4me3 data from divergent meat
quality, such as OSTF1, NRAS1, and KCNJ11. Interestingly, 75 high-altitude adaptive candidate
genes were also detected in the list. This study is a first step toward
high quality beef of the Tibetan Plateau and provides useful information
for their molecular understanding.