| The negative effect of excessive deposit lipid to poultry industry had became more concerned due to continue growth selection during the long period, molecule breeding to those special chicken fat traits turn to be a optimistic field. The contend of this research was screening polymorphism of chicken lipoprotein lipase gene (LPL) and analysis whether it could be a candidate gene or molecular marker to improve chicken fat traitsPCR-SSCP analysis was used to detect SNP in LPL on a 545 chicken population which was rear in the same condition and composed of 4x4 diallel cross involving 4 breeds-White Leghorn (A), Silkies(C), CAU Brown (D) and White Plymouth Rock (E).15 primers was designed in order to get DNA fragments which should cover the 5' flanking and functional sites of LPL by PCR. The results of SSCP analysis on those DNA fragments told us that 5 sites named a, b, d, e, f in 5' flanking and exon3, exon6, exon7, exon8, exon9 had polymorphisms in this population.By cloning and sequencing those DNA fragments appeared polymorphisms we found 18 SNPs in 5' flanking and 5 SNPs in exon region, they were as following: A-1909G, -1865C insertion, C-1811T, C-1669T, C-1087T, A-1079G> -983G deletion , C-775G, C-536T, C-436T, T-397C, A-364G, A-342G, C-298T, C-278G, G-277C, A-274G, T6731C, A10407G, G11382C, C12315T, A13644G, in which G11382C and A13644G were non-synonymous substitution, they resulted in Ala→Pro, Asp→Gly respectively.We searched the potential 5' regulatory elements and protein factor binding to 5' flanking by transcription factor analysis tool TFSEARCH verl.3 on line. The result clewed that -1865C insertion, C-1811T, A-1079G, -983G deletion, A-364G, C-278G, G-277C may had some effect on the regulation of c LPL expression because those mutation cause changes in the number and kinds of transcription factor binding to 5' flanking.Association analysis of chicken fat traits and LPL gene polymorphisms were done by SAS software and the results showed that combination and live weight had significance effect on fat traits ( P<0.01), two sites d and e in 5' flanking had significant effect on thickness of subcutaneous fat (P<0.05),and site d also had very significant effect on abdomen fat weight ( P<0.01).Mutiple range compare indicated that the thickness of subcutaneous fat difference between genotype EE and EF or FF at site d were significant(p<0.05), the abdomen fat weight of geneotype EE and EF were much higher than FF(p<0.01 ),and the thickness of subcutaneous fat of different genotype of site e were not significant different(.P>0.05) .The genotype compounding of sites d and e had significant effect on those three fat traits (p<0.05,p<0.01, p<0.01) and revealed that interaction between locus had important effect in association analysis. The polymorphisms of exon8 were remarkably associatied with interamuscular fat width (p<0.05) but the interamuscular fat width of different genotype were not significant different(P>0.05)All those result indicated that LPL had polymorphisms in this population and polymorphisms of site d and e in 5' flanking were remarkably associatied with thickness of subcutaneous fat and abdomen fat weight variance. |
