Studies On The Single Nucleotide Polymorphism Of FAS Gene Associated With Fatty Liver Traits In Geese

In this study,DNA sample were extracted from 124 Lang De geese.FAS gene is considered as a candidate gene which strongly relates to the fat traits,so nine pairs of primers in 5' promoter and code area were designed to clone and sequence the FAS coding regions of Lang De geese.The contents of this research was to find polymorphism of FAS(fatty acid synthetase)to analyse whether it could be a candidate gene,or molecular marker to improve geese fat liver traits.The analysis of PCR-SSCP showed that there were three genotypes detected in the population of P₁ and P₂ sites,and genotypes were detected in the population of P₈.The frequencies of genotype E and F were 0.569 and 0.431,C and D were 0.630 and 0.370,A and B were 0.657 and 0.343.The genetype frequencices of EE,EF and FF were 0.380,0.242 and 0.380;CC,CD and DD were 0.355,0.113 and 0.549;AA and AB were 0.315 and 0.685.X² test showed that there was significant difference(P＜0.05) between distributions of genotypes and theoretical proportion in the P₁,P₈ population,occupying Hardy-Weinberg equilibrium,and only P₂ in Hardy-Weinberg equilibrium.We found SNPs in 5' promote and exon region by analysis of PCR-SSCP.There were two SNPs in 5'UTR region P₁-54bp(T/C),P₂-545bp(A/G),and one SNPs in exon region at 3205bp.by cloning and sequencing those DNA fragments appeared polymorphism the potential elements and protein factors binding to the 5'-region by transcription factor analysis tool TFSEARCHverl.3 on line.We predicted that T→-54C,A→-545G may had some effect on the regulation of FAS pression because those mutation cause changes in the number and kinds of transcription factor binding to 5'UTR.Association analysis of geese fat traits and FAS gene polymorphism was made by SPSS software and the results showed that P₁,P₂ single polymorphisms had significant effect on fat liver traits(P＜0.05), and EF genotype fatty liver average weight was 829.46g,the EF genotype and FF genotype had significant higher fatty liver than EE genotype(P＜0.05) in primer P₁,DD genotype fatty liver average weight was 813.31g,the CD genotype and DD genotype had significant higher fatty liver than CC genotype(P＜0.05) in primer P₂.The ABDD genotype fatty liver average weight was 905.23g,had significant difference to other genotypes(P＜0.05).The genotypes of fatty liver weight over 800g from heavy to light were ABDD,DDEF,DDFF,DDEE,ABEF,ABFF,AADD,CDEFand the other characters in different genotypes had significant difference among each oher(P＞0.05).All those results indicated that the FAS had polymorphisms in 5'UTR and exon area.The gene polym orphism of primer P₁ and P₂ in 5'UTR were remarkably associated with fat liver traits.The results indic ated that FAS 'SNP was helpful to increase fatty liver level.