Study On Laying Performance Of Yuxi Dark-skin Chicken By Microsatellite And RAPD Marker

Yuxi Dark-skin chicken is a new variety of broilers, but the reproductive performance of breeding chichens is very low. Improve its reproduction together with its good meat properties would reduce the cost of this variety as breeding chichens. The traditional method to approach this is costful and is drasti cally affected by environment. However, molecular markers almost with no environmental effect could provide some information for quantitative trailt locus (QTL) analysis. Today random random amplified polymorphic DNA (RAPD) and microsatellite are commonly used to find molecular markers.In order to find the molecular markers suitable for selective breeding, the microsatellite and the RAPD were used to study genomic DNA of 180 slow feacther strain of Yuxi Dark-skin chickens.The major factors such as the Mg²⁺ concentration, annealing temperature, extending time and cycle times affecting RAPD amplification were optimized by the orthogonal experiment. With 15 genomic DNA samples as templates, for all 26 random palmers, the amplification conditions of RAPD PCR of were screened. The amplification condition for each primer with suitable size bands displaying clearly on the gel by agarose gel electrophoresis was used for RAPD PCR. The data revealed that the PCR products of 10 out of the 26 primers displayed obvious bands with 100-2000bp suitable for RAPD analysis. Among them, the PCR products of 5 random primers showed polymorphic bands.The 5 polymorphic primers were used to do RAPD analysis with the 180 genomic DNA samples. The coefficients of genetic similarity and diversity were calculated for decide of Yuxi Dark-skin chickens trim degree.The production performance of chickens with the polymorphic bands was compared with that of those without the polymorphic bands, using least square analysis. It wasn't found that band was correlated to the laying rate (P＜0.05), but band S87-â…¢and S98-â… were found correlated to the egg weight (P＜0.05).Genotypes of these chickens were analyzed according to the band patterns of the PCR product of each polymorphic primer displayed on the agrose gel. There was only one chicken in 3 genotypes of the primer S108, being not suitable for statistical analysis. For the rest of polymorphic primers, the laying performance of different genotype chickens were compared to each other, using least square analysis. The result showed that the production performance of different genotype chickens was significantly different. For primer S87, chickens of genotype B displayed higher laying rate than the chickens of other genotypes (P＜0.05); the egg weight of chickens of types C, E and F was highly significantly different to that of others (P＜0.01),.For primer S98, chickens of type E displayed significantly lower laying rate than others (P＜0.05), the egg weight between type E and H chickens was significantly different (P＜0.05), For primer S102, chickens of type G displayed significantly lower egg weight than others (P＜0.05),. For primer S 113, chickens of type G and F displayed significantly lower laying rate than others(P＜0.05), the laying rate of chickens of types A and D was highly significantly different to that of others (P＜0.01),The 180 DNA samples were also used to do the polymorphism analysis using 2 mirosatellite primers choosing from the poultry genome, rich polymorphism was found via polyacrylamide gel electrophoresis. The 2 mirosatellite marker showed 4 and 5 alleles, respectively, and their heterozygosity is 0.7422 and 0.7914, polymorphic information content is 0.6467 and 0.7648. The chickens with different patterns on PAGE gels had no significantly different least square value of laying performance. (P＞0.05).In conclusion, the RAPD bands S87-â…¡, S98-â… are possible molecule markers for Yuxi Dark-skin chickens. Genotype B and C of marker S87 and Genotype G of marker S 102 displayed higher production performance. However, whether or not these markers were true molecule markers for the breeding of this variety should be elustrated with further study.The finding of this study provided some basic references for production traits in Yuxi Dark-skin chickens with molecule level, the results also provide some credible information for quantitative traits locus study and marker assisted selection (MAS). All these will accelerate the progress of breediong.