SNPs Of The Genes Related To Fat Metabolism And Their Association With Meat Quality In Chaohu Duck

The content of intramuscular fat can affect meat tenderness and flavor on poultry. Chaohu duck was secleted as the research object, the IMF content of breast muscle and leg muscle was determined by Soxhlet extraction, the genetic variation of ApoVLDL-Ⅱ-、A-FABP、CYP7A1 and its correlation with meat qulity traits were studied by PCR-SSCP and DNA sequencing technology, and the mRNA expression on different genotypes of liver tissue was tested through RT-PCR. These results had a good value for choosing fat traits candidate molecular markers of meat ducks. The specific research results were as follows:1. Analysis of meat quality traits of Chaohu duckThe IMF, PH, tenderness, driage and proportion of meat quality traits in Chaohu duck were measured. There was no difference between the leg muscle IMF content of male duck (1.75% ± 0.85%) and that of female duck (1.81% ± 0.85%) (P>0.05), the breast muscle IMF content of male duck (2.08% ± 0.69%) was significant higher than that of female duck (1.74% ± 0.60%) (P<0.05). The PH of breast muscle and leg muscle was between 6.51 ±6.75, the driage was between 0.74%-0.78%, the proportion was between 0.10%±0.14%. The tenderness of breast muscle and leg muscle of male duck were 12.41 kg ± 6.61 kg and 7.97 kg ± 8.46 kg, that of female duck were 12.72 kg ± 6.06 kg and 18.10 kg ± 6.12 kg, but there were no difference between them (P>0.05).2. Analysis of gene SNPs and linkage disequilibrium with meat quality traits in Chaohu duckThere were three SNPs detected by PCR-SSCP of ApoVLDL-Ⅱ gene. A�'G mutation at 688 bp of the first intron, the group was divided into three genotypes, named MM, MH, HH, the gene frequency was 0.57,0.36,0.07. C�'T and T-C mutation at 2723 bp and 2743 bp of the third intron, the group was divided into three genotypes, named CC, CT, TT, the gene frequency was 0.59,0.34,0.07. The alleles number of two loci were 1.6 and 1.57, the heterozygosity of two loci were 0.38 and 0.36, the PIC of two loci were 0.30 and 0.30, belonged to moderate polymorphism The two loci were in Hardy-Weinberg equilibrium state (P>0.05).There were three SNPs detected by PCR-SSCP of A-FABP gene. A�'G mutation at 321 bp of the first intron, the group was divided into three genotypes, named BB, BD, DD, the gene frequency was 0.55,0.35,0.10. T�'C and C�'T mutation at 944 bp and 1054 bp of the first intron, the group was divided into two genotypes, named AA, AQ the gene frequency was 0.26,0.74. The alleles number of two loci were 1.66 and 1.88, the heterozygosity of two loci were 0.40 and 0.47, the PIC of two loci were 0.32 and 0.36, belonged to moderate polymorphism. The A321G loci was not in Hardy-Weinberg equilibrium state (P<0.01), the T944C、C1054T loci were in Hardy-Weinberg equilibrium state (P>0.05).There were one SNPs detected by PCR-SSCP of CYP7A1 gene. C�'T mutation at 203 bp of the first extron, the group was divided into two genotypes, named EE, EF, the gene frequency was 0.89,0.11. The number of alleles of the loci was 1.12, the heterozygosity of the loci was 0.10, the PIC of the loci was 0.10, belonged to low polymorphism. The C203T loci was in Hardy-Weinberg equilibrium state (P>0.05).3. Analysis of SNPs and mRNA expression of gene and their association with meat quality of Chaohu duckIn ApoVLDL-II gene, the mRNA expression of different genotypes has no significant difference (P>0.05), the gene mRNA expression, breast muscle and leg muscle IMF, breast muscle and leg muscle tenderness of HH genotype were higher than that of MM and MH genotypes, the breast muscle and leg muscle PH, breast muscle and leg muscle driage were lower than that of MM and MH genotypes. The Breast Muscle IMF of male duck was significant higher than that of female duck (P<0.05), the leg muscle tenderness of male duck was highly significant higher than that of female duck (P<0.01). The leg muscle IMF of TT genotype was highly significant higher than that of CC and CT genotypes (P<0.01). The gene mRNA expression, breast muscle IMF, breast muscle and leg muscle tenderness of TT genotype were higher than that of CC and CT genotypes, the breast muscle and leg muscle PH, breast muscle and leg muscle driage were lower than that of CC and CT genotypes. The breast muscle IMF and leg muscle tenderness of male duck were significant higher than that of female duck (P<0.05).In A-FABP gene, the mRNA expression of different genotypes has no significant difference (P>0.05), the breast muscle and leg muscle tenderness of BB and BD genotypes were highly significant higher than that of DD genotype (P<0.01), and the breast muscle driage significant higher than that of DD genotype (P<0.05), there was no significant difference between BB and BD genotypes. The breast muscle PH of male duck was highly significant higher than that of female duck (P<0.01) in T944C and C1054T loci, and the leg muscle PH of male duck was significant higher than that of female duck (P<0.05).In CYP7A1 gene, there was no significant difference among gene mRNA expression, breast muscle and leg muscle IMF, breast muscle and leg muscle PH, breast muscle and leg muscle tenderness, breast muscle and leg muscle driage and breast muscle and leg muscle rate of genotypes and gender (P>0.05).From the above results, it is suggest that ApoVLDL-Ⅱ gene and A-FABP gene can chose as the candidate genes on Chaohu duck meat quality traits selection.