Research On Sequence And Polymorphism Of Porcine Uncoupling Protein Gene 3

Improvement of porcine meat quality is always one of the main goals for livestock genetics and breeding.At present.It is more important for technicians to produce pork with the lean and good quality,while people tend to be interested in meat quality when the standard of living condition has been improved.In this paper,we selected the Uncoupling Protein Gene-3(UCP3) as the candidate gene for carcass and meat quality,and meanwhile analyzed its gene effects and the pattern of effects.1. doing of UCP3 gene 3'-cDNA translated region and detection method of its single polymorphism(SNP)-PCR-SSCPUsing the porcine cDNA sequence.primers of UCP3 gene were designed and were applied to amplify the gene from four different porcine total RNA of longissimus dorsi muscle.Four breeds' fragments of 574bp length were got and we compared the differences of their sequences.The compared results showed that there were three single nucleotide mutations in UCP3 gene 3'-cDNA translated region, of which the mutation of 842bp in ORF can result in the change of ammo acid sequence.PCR-SSCP scanning of 139 F2 and 321 Fl individuals of pig resource families showed that:(1) UCP3 gene showed three genotypes(AA,AB and BB).Their disstribution indicated that allele A seemed predominant in the following populations: Large Whitex Meishan F2 and Fl, Large White, Landrace, Large White Landrace, Landrace x Large White, and the ranges of allele frequencies was 0.71-0.87;in contrast.allele B was 0.13-0.29.However,the frequencies of allele B were 0.56 and 0.55 respectively.(2) Association analyzing of UCP3 polymorphism with carcass traits in 139 F2 Large WhitexMeishan individualsSignificant association between the UCP3 genotypes and thorax-waist fat thickness,height and area of longissimus dorsi muscle(LD) was found.Pigs with the AA genotype had approximately 14.2% less average thorax-waist fat thickness than those with the AB genotype(P<0.01)and the height and area of longissimus dorsi muscle(LD) of BB genotype individuals were 7.8% and 11.2% less than AB genotype ones(P<0.05).UCP3 gene played a role mainly in the pattern of additive effect on carcass traits.The additive effect values of longissimus dorsi muscle height and estimated lean meat percentage were -0.348(P<0.05) and -9.281 respectively(P<0.01).(3) Association analyzing of UCP3 polymorphism with meat quality traits in 139 F2 Large WhitexMeishan individualsIt showed that UCP3 genotypes had significant association with water lost rate, water holding capacity, meat color(LD)(P<0.05), and water(LD) (P<0.01).The AA genotype individuals had 4.0%, 18.2% respectively less than BB genotype ones in waterlost rate, meat color, but had 8.3% more water holding capacity than pigs with BB genotype. To the water(LD),the AA genotype pigs were 0.65 more than AB ones.We also found that UCP3 gene' additive effect on meat quality predominated in the population,and the additive effect values of water lost rate,water holding capacity,meat color(LD) were 2.750(P<0.05), -3.795(P<0.05), -2.012 (P<0.05) respectively.(4)Scanning results of UCP3 polymorphism on carcass traits in 81 Fl Large WhitexMeishan resource familyExcept for the significant association with shoulder fat thickness(P<0.05),we found no more significance in the association with other carcass traits. It showed that the BB genotype pigs were 11.3% less should fat thickness than AA genotype ones.2. UCP3 gene 3'-UntransIated Region' polymorphismThe 696bp fragement of UCP3 gene 3'-Untranslated Region was gained after amplifying. Using Ava I , PCR-RFLP scanning in 139 F2 resource family indicated that there was no significant association of 3'-Untranslated Region' polymorphism with carcass traits and meat quality traits as well. However, the region of UCP3 gene seemed to play a mainly additive effect on water(LD):-0.388(P<0.05).