Isolation And Polymorphic Analysis Of Microsatellite Loci For Fujian Indigenous Duck Breeds

Microsatellites are generally considered to be the most powerful mendelian markers currently available for population genetic studies because they are highly variable,more likely to be neutral as compared with other genetic makers,and results are reproducible. The purposes of this study were to isolate some microsatellite DNA sequences by microsatellite libraries, to design primers by using the sequences, to detect the population genetype of Fujian indigenous duck by PCR amplification and the number of the amplification fragment, to analyze the allele frequencies, polymorphism information content (PIC), heteroygosity (H), effective number of alleles, genetic distance and results of dendrogram, and to discussed the genetic variability and population structure in duck breeds.In this study, microsatellite-enriched libraries, which enriched for (GA)n, (CT)n, (CA)n and (TG)n, were constructed using enrichment by magnetic beads. A total of 14 microsatellite clones were identified in 46 masculine cloning and 14 primer pairs with microsatellite repeats were designed to submit to GenBank (GenBank accession number:FJ599499-FJ599512). Of the 14 primer pairs, 5 microsatellite loci were isolated using PCR optimization, which were showed middle or high polymorphism and were used for analyzing genetic diversity of the 5 Fujian indigenous ducks..Microsatellite analysis of the population genetic constitution indicated:①For the 46 microsatellite loci examined, the total number of alleles was 31 in 5 breeds, and the mean allelic number of per locus was 6.2.②The mean PIC of 5 microsatellite loci in 5 indigenous duck breeds was 0.5133. Mean PIC of FJAU011 was the highest (0.5860). The average efficient allelic number was between 2.1652 and 3.9904.The mean heterozygosisty was from 0.5115 to 0.7000.③The Hardy -Weinberg equilibrium analysis revealed that only a few loci were equilibrium,more genetic disequilibrium was showed at most of the loci in 5 duck breeds.④The F-statistic analysis indicated that the FST of different locus varied from 0.1035 (in FJAU013) to 0.2287 (in FJAU001), and the average was 0.1586.The Nm was from 0.8431 (in FJAU001) to 2.1659 (in FJAU013), the mean was1.3259.⑤The dendrograms were drawed with Ds and DA genetic distances. 5 indigenous duck breeds were clustered into 2 groups based on the results of dendrogram.In the dendrogram, one group included the four Fujian indigenous duck breeds (Liancheng white duck, Putian black duck, Jinding duck, and Shanma duck; the other group included Muscovy.