Molecular Phylogeography Of Perinereis Aibuhitensis

Perinereis aibuhitensis is widespread in the coast of China, it is a commerciallyimportant fishery product of China, Now. In the present study, microsatellite makerswere developed and characterized by magnetic beads enrichment methods from thegenome of Perinereis aibuhitensis. Mitrochondrial DNA sequence, microsatelliteDNA makers were used to estimate its gene diversity, population structure andphylogeographic pattern. The main results are as follow:(1) Used the magnetic beads enrichment methods, SSR sequences were screenedfrom the genome of Perinereis aibuhitensis. Primers were designed for39SSR locis.20primer pairs amplified the target DNA frgments and8primer pairs werepolymorphic in the Perinereis aibuhitensis.The polymorphisms of these locis wereanalyzed in24individuals from Jiaonan population. The number of alleles at eachlocus ranged from6to20.The observed and expected heterozygosity varied from0.375to0.875and from0.59to0.946, respectively. Two loci were found deviatesignificantly from Hardy–Weinberg equilibrium. These microsatellite loci will beuseful for further studies on the population structure and genetic variation of thisspecies.（2）Eight geographic populations of Perinereis aibuhitensis were sampled fromthe coast of China. Mitochondrial DNA cytochrom oxidase subunit Ⅰ gene wasanalysed in152individuals. Results showed that the sample Perinereis aibuhitensispopulation had low haplotype diversity and nucleotide diversity. Topologies ofneighbour-joining tree were shallow and the network showed that no significantgenealogical structure corresponding to sampling locations existed. Significantgenetic differentations were detected among the eight population based on theAMOVA, pair-wise Fst. Neutrality tests and mismatch distribution showed populationexpansion in Perinereis aibuhitensis.（3）Six microsatellite DNA loci were used to invertigate the genetic diversity andpopulation structure of Perinereis aibuhitensis.The result indicated polymorphism information content（PIC）and observed heterozygosity were high，indicating a highlevel in gene diversity of Perinereis aibuhitensis. Significant genealogical branchesand clusters corresponding to sampling localities were detected by UPGAM tree. Theresults of AMOVA analysis and pairwise Fst values showed genetic divergenceamong different geographic populations and the gene flow was limited. Significantpopulation genetic structure was detected among Perinereis aibuhitensis population，which might be caused by the complicated interaction between geographic positionand geographical distance.