Genome Scan In 2, 5 And 7 Chromosome Of Chickens For Quantitative Trait Loci Affecting Meat Traits

Because of pursuing the growing speed and meat productivity ,it resulted in the decreasing of meat quality and economic losses in chicken industry. Now, people tend to be interested in meat quality when the standard of living has been increased.Meat quality are quantitative trait and affected By polygene. Therefore,it is difficult to improve the meat quality with the application of traditional breeding.The development and application of genetic markers provided a chance to solve this problem.Based on the resource populations constructed from Gushi-Anak crossing,the study detect the QTLs for meat traits by genome scanning with 39 microsatellite markers located on chromosome 2,5 and 7 of chicken, which of 20 microsatellite markers were selected in the chromosome of 2, covering 474 cM, the average distance is 23.7 cM, 10 microsatellite markers were selected in the chromosome of 5 ,covering 170 cM, the average distance is 17 cM, 9 microsatellite markers were selected in the chromosome of 5 ,covering 160 cM, the average distance is 18cM.By using the soft of QTLExpress several QTL are identified,and localized on chromosome 2,5 and 7 .The result indicates:1.The analysis of phenotypic values indicated that the measured traits on meat quality were segregating well in F2 individuals.The population size is large enough.It can promise the scale and density of and the accuracy of QTL mapping.Therefore,the construction of resource populations achieved the expected aim .2. The PCR conditions for 39 microsatellite markers in the resource family were selected. The mean of the polymorphic information content was 0.618,and the mean heterozygosity was 0.773,Which demonstrated that the microsatellite markers we selected had relatively high information content and these markers could be used to construction of linkage map and detection of quantitative trait loci(QTL).3. With the software of QTL Express,we have found the 39 QTLs for meat quality on chromosome 2,5 and 7 in all.The QTLs for 16 meat quality were detected on chromosome 2.The QTLs for 14 meat quality including water content, inter-muscular fat width, muscle water holding capacity,pH value of leg muscle , pH value of chest muscle, meat tenderness , the diameters of muscle fiber (the diameters of breast muscle fiber and the diameters of leg musclefiber),inter-muscularfatwidth(IMF),alkalinephosphatase(AKP),totalprotein(TP),totalcholest erol(CHO) and creatine phosphokinase(CK)were detected on chromosome 5.On chromosome 7,the effect of QTLs on 13 meat traits were detected, including water content, inter-muscular fat width, muscle water holding capacity(water loss of chest muscle and leg muscle ),pH value of muscle(pH value of leg muscle and pH value of chest muscle), chest meat tenderness,alkalinephosphatase(AKP),totalprotein(TP)and creatine phosphokinase(CK) 4.QTL for tighly correlative traits were located on the same or adjacent chromosomal loci.For Example,QTL for shear force of chest muscle representing chest muscle tenderness and shear force of leg muscle stander for leg muscle tenderness were all located 0 and 6 cM on chromosome 5,respectively.;at the same time, the diameters of breast muscle fiber and the diameters of leg musclefiber were also located 41 and 49 cM on chromosome 5,respectively;on chromosome 2 , the QTL for pH value of leg muscle and pH value of chest muscle were located 253 and 254 cM ,respectively;on chromosome 7, the QTL for pH value of leg muscle and pH value of chest muscle were located 100 and 110cM, respectively.