Study On Genetic Variation Within And Among Populations Of 12 Chinese Indigenous Chicken Populations Using Microsatellites & The Relationship Between Microsatellites And Production Performances In Luyuan Chicken

The genomes of Chinese indigenous chicken breeds were screened using microsatellites as molecular markers. A total of 12 Chinese indigenous chicken breeds including Luyuan, Gushi, Tibetan, Baier, Xianju, Chahua, Dagu, Beijing Fatty, Langshan, Henan Game, Silkies and Xiaoshan chickens were typed for 29 microsatellite loci. The allele frequency, Hardy-Weinberg equilibrium and genetic variation among populations were determined. The consensus trees based on Dc using NJ and UPGMA method were studied to analyze the relationship among Chinese indigenous chicken breeds. The study also analyzed the relationship between microsatellite loci and production performance. The results were as follows:1. The polymorphisms of 29 microsatellite loci detected in 12 Chinese indigenous chicken breeds were abundant and a total of 228 alleles were observed. There were 23 alleles in LEI234, which was most. And the least was MCW103 and MCW098, which only had 2 alleles. The mean number of alleles was 7.86 + 5.19 in every microsatellite locus. The mean observed heterozygosity was 0.4471, and the mean expected heterozygosity was0.5453 in all populations.2. Hardy-Weinberg equilibrium was detected for each breed over loci. It showed that no significant deviation was detected in 8 of Chinese indigenous chicken populations except for Beijing Fatty Chicken, Luyuan Chicken, Langshan Chicken and Chahua chicken. Heterozygosity absence was found in Luyuan Chicken and Chahua Chicken, and in Beijing Fatty Chicken and Langshan Chicken was overplus.3. There was significant differentiation among the populations and also between each pair of the 12 populations. The degree of population subdivision calculated from the classical estimator θ was around 16.6%, and there was no significant difference among the three estimators θ, Gst and psr using Friedman test.4. The consensus trees were constructed based on Dc using NJ and UPGMA method respectively. Five populations were always on one side of the trees, including Chahua, Tibetan, Gushi, Xianju and Baier. Tibetan and Chahua grouped in both trees, and so were Xianju and Baier. But the place of Gushi was different in both trees. Other populations were on the other side of trees. Xiaoshan, Luyuan and Beijing Fatty populations clustered as one branch of the tree.5. The relationship was studied between microsatelite loci and production performance at the age of 12 weeks old in Luyuan chicken. The results showed that, in 29 microsatellite loci, there were relationships between body weight and three microsatellite loci, which were ADL278 on chromosome 8, LEI 166 and MCW222on chromosome 3. MCW216 on linkage group of E48C28W13W27 had an effect on body length. Three loci related with chest bone length, including MCW020 on chromosome 1, MCW067 on linkage group of E29C09W09 and MCW222 on chromosome 3. There were three loci affecting on thurl width, including MCW216 on linkage group of E48C28W13W27, ADL112 on linkage group of E29C09W09 and MCW103 on chromosome 3. MCW222, which was on chromosome 3, significantly affected shank length of Luyuan chicken attwelve weeks of age. MCW067 on linkage group of E29C09W09 related to shank circumference. LEI 166 on chromosome 3 affected water lost rate of breast muscle and dressing percentage. MCW165 on E27C36W25W26 and MCW222 on chromosome 3 showed relation with the percentage of breast muscle yield. MCW103 on chromosome 3 related with egg production while MCW248 on chromosome 1 relate with mean egg size.