Expression Character And Genetics Effect Analysis Of Bovine Candidate Genes For Meat Quality Traits

The bioinformatics, PCR-RFLP, PCR-RFLP, RT-PCR, DNA sequencing and DNA sequence analysis techniques were applied to (1) clone bovine CAV1 and CAV3 gene, (2) analyze the genetic variations and characters of CAV1,CAV3,CAPN1,CAPN3,CAST,HRSP12 and CACNA2D1 genes and (3) their association with meat quality traits and carcass composition traits, including Live weight (LW), Carcass weight (CW), Dressing percentage (DP), Meat percent(MP), Marbling score (MS), Loin muscle area (LMA), Meat color (MC), Fat color (FC), Backfat thickness (BF), Meat tenderness(MT) and Average daily gain(ADG) in 323 cattle, which comprised of nine breeds, namely, Simmental (n=110), Angus (n=48), Luxi (n=30), Qinchuan (n=29), Jinnan (n=24), Charolais (n=30), Limousin (n=25), Hereford (n=30) and Simmental×Mongolian, (4) analyze the expression of CAV1,CAV3,CAPN1 and CAPN3 gene. These results will benefit for the application of DNA marker related to the economic traits on marker-assist-selection (MAS), improvement and promotion of local cattle breeds. The main results were shown below:1.Whole coding sequence (CDS) and partial untranslated sequence (UTR) of bovine CAV1 and CAV3 gene were isolated from the muscle of Simmental by e-PCR and RT-PCR techniques.2. The amino acids sequence deduced by ORF of CAV1 and CAV3 cDNA were analyzed while the character and protein domain were predicted by bio-informatics, The results showed that bovine CAV1 and CAV3 protein were consisted of 178 and 151 amino acids respectively. They both contained Transmembrane domains (was consisted of 22 amino acids). The amino acids sequence in the domain showed high conservation in different species.3. 32 SNPs were identified by PCR-RFLP, PCR-SSCP and sequencing in bovine CAV1,CAV3,CAPN1,CAPN3,CAST,HRSP12 and CACNA2D1 gene and 19 of them were transition mutation.4. Genetic variations in bovine CAV1,CAV3,CAPN1,CAPN3,CAST,HRSP12 and CACNA2D1 genes were associated with carcass and meat quality traits. The results showed that:(1) CAPN1-StuⅠsite was significantly associated with MS and MT. Animals with AA genotype were significantly higher than those with BB genotype (P<0.05). CAPN1-AgeⅠsite was significantly associated with LW. Animals with AB and BB genotype were significantly higher than those with AA genotype (P<0.05). CAPN1-MaeⅡsite was significantly associated with LW, DP, MP, LMA, MT and ADG. Animals with BB genotype had significantly higher LW than those with AA (P<0.01). Animals with AA genotype had significantly higher DP, MP, LMA and MT than those with AB and BB (P<0.01). Animals with AA and BB genotype had significantly higher ADG than those with AA genotype (P<0.05). SSCP-CAPN1αsite was significantly associated with MT ADG and FC. Animals with AA genotype had significantly higher MT (P<0.05) and lower ADG and FC (P<0.01) than those with AB and BB genotype. SSCP-CAPN1βsite was significantly associated with BF, MS and MT. Animals with AA genotype had higher MS and MT than those with AB genotype (P<0.01), and had higher BF than those with BB genotype (P<0.01).(2) CAPN3-TaqⅠsite of CAPN3 gene was significantly associated with CW. Animals with AB genotype had larger CW than those with BB genotype (P<0.05).(3) CASTαsite was significantly associated with MS and MT. Animals with BB genotype had larger MS than those with AA genotype (P<0.05). Animals with BB genotype had larger MT than those with AA or AB genotype (P<0.01).(4) HRSP12-BsrⅠsite of HRSP12 gene was significantly associated with LW, CW and MS. Animals with AB genotype had larger LW and CW than those with BB genotype (P<0.01). Animals with AA genotype had larger MS than those with BB and AB genotype (P<0.05).(5) Animals with BB genotype in CAV1-AvaⅡsite had larger LW, CW, MS and MT than those with AA genotype (P<0.01). Animals with BB genotype in CAV1-HinfⅠsite had larger LW and ADG than those with AA genotype (P<0.05). Animals with BB genotype in CAV1-BglⅠsite had larger LW than those with AA genotype (P<0.05). Animals with AA genotype in CAV1-MspⅠsite had larger LW, CW, LMA and MT than those with AB and BB genotype (P<0.05).(6) CAV3 gene was significantly associated with LW, DP and MP. Animals with BB genotype had larger LW than those with AB genotype (P<0.05). Animals with AA genotype had larger DP than those with BB genotype (P<0.05). Animals with BB genotype had larger MP than those with AA and AB genotype (P<0.05).(7) CACNA2D1-HaeIII site was significantly associated with CW, DP, MP and BF. Animals with BB genotype had larger CW and DP than those with AB genotype (P<0.01). Animals with AA genotype had larger MP than those with AB genotype (P<0.01). Animals with BB genotype had larger BF than those with AA and AB genotype (P<0.01) and there was no significant difference between animals with AA and AB genotype. 5. Expression of four candidate genes (CAPN1,CAPN3,CAV1,CAV3) were detected in 9 tissues, which were collected from four different physiological phases: embryonic phase,12 months old,24 months old and 36 months old, by RT-PCR and Real-time Q-PCR, and the results showed that:(1) The CAPN1 mRNA expression in lung, muscle, kidney, rumen and spleen in embryonic phase was significantly higher than the other phases.(2) The CAPN3 mRNA expression in muscle and heart in embryonic phase was higher than the other three phases (P<0.01).(3) The CAV1 mRNA expression in fat tissue in the 12 months old, 24months old and 36months old was significantly higher than the embryonic phase (P<0.01). The CAV1 mRNA expression in muscle in 24months old and 36months old was significantly higher than the 12 months old and embryonic phase (P<0.01).(4) The CAV3 mRNA expression in muscle in the 24months old and 36 months old was higher than the embryonic phase and 12 months old (P<0.01). The CAV3 mRNA expression in small intestine in the 12 months old,24months old and 36months old was significantly higher than the embryonic phase (P<0.01).