Abstract:

To investigate the expression characteristics of the PDK4 gene in various tissues of Meiren yaks and to explore its correlation with the mechanism of fat deposition,tissue samples were collected from the longest and dorsal muscles,heart,liver,spleen,lung,kidney,fat and testis of Meiren yaks,and total RNA was extracted.The gene was amplified,analyzed and characterized by RT-PCR,bioinformatics software,and qPCR.The results showed that the CDS region of the PDK4 gene was 1 224 bp,407 amino acids,the relative molecular mass of protein was 46.159 14 ku,the theoretical isoelectric point was 6.60,and the total average hydrophilicity was-0.169,which was a hydrophilic protein;the phylogenetic tree results showed that Meiren yak was the closest related to wild yak and the most distant related to hyena;PDK4 protein had 34 phosphorylation sites,no signal peptide and transmembrane region,and mainly plays a biological function in mitochondria;the PDK4 protein of Meiren yak was mainly composed of α-helix and irregular curling.The expression of the PDK4 gene in the liver and lung of 7-day-old Meiren yak was significantly higher than that of other tissues (P<0.05),moderately expressed in muscle,fat,spleen,and testes,and low in the kidney and heart.As the yak aged,the expression of the PDK4 gene in the adipose tissue of 30 months old Meiren yak increased and was significantly higher than that in the fat of 7-day-old Meiren yak(P<0.05).The above results suggest that the PDK4 gene may be involved in fat regulation during the growth process of Meiren yak and play an essential role in the fat deposition process.

Key words: Meiren yak, Pyruvate dehydrogenase kinase 4 gene(PDK4), Cloning, Real-time Fluorescent Quantitative PCR