Cloning, Expression Profiling And Polymorphism Of Several Genes Related To Energy Molecule Transport And Metabolism In Yak

The main purpose of this study was to analyze the sequence and expression characteristics of several genes related energy molecule transport and metabolism in the yak (Bos grunniens) muscle under high altitude hypoxic environment.The genes studied include glucose transporter 4 (GLUT4), monocarboxylate transporter 1 (MCT1), monocarboxylate transporter 4 (MCT4), and lactate dehydrogenase-1 (LDH-1).Jiulong yaks were used in the present experiment.cDNA sequences for GLUT4, MCT1, and MCT4 gene were cloned by RT-PCR.The expression of GLUT4, MCT1 and MCT4 genes were assayed by real-time fluorescence quantitative PCR in longissimus muscle and quadricep of Jiulong yaks at different ages and compared with those of cattle.The cDNA sequence of three genetic variants of LDH-1 gene were cloned by RT-PCR, and a PCR-RFLP protocol was developed to detect nucleotide mutation in one type of LDH-1 variant using genomic DNA.The main results are as follows:1. The full-length CDS sequences and corresponding amino acid sequence length of GLUT4, MCT1, MCT4 gene of Jiulong yak were 1530bp /509AA, 1506bp/501AA, 1386bp/460AA, respectively.These genes showed over 99% similarities of nucleotide and deduced amino acid sequences between yak and cattle.2. Analysis of the expression of GLUT4, MCT1 and MCT4 gene in muscles showed that the MCT1 mRNA level between bovine longissimus muscle and quadriceps had significant difference (P<0.05); The MCT1 mRNA levels in longissimus muscle between Jiulong yak and cattle were significantly different (P<0.01).3. The full-length CDS sequences of LDH-1 genetic variants (LDHB-F, LDHB-M, LDHB-S) in Jiulong yak were all 1005bp, encoding 334 amino acids.Two sense mutations are as follows: the A689C mutation in LDHB-S and the G896A mutation in LDHB-F, resulting in two amino acid substitutions, ie, E230A in LDHB-S and R299Q in LDHB-F variant.4. a PCR-RFLP method was established to detect the G896A mutation in LDHB-F. The frequency of allele A and G were 0.26 and 0.74, respectively.The frequency of three genotypes AA, AG and GG were 0.04, 0.43 and 0.53, respectively.