Development Of Polymorphic Microsatellites For Pampus Argenteus And Its Analysis On Population Genetic Structure

The silver pomfret (Pampus argenteus), belonged to the family Stromateidae, is one ofthe most famous commercial sea fish species and lots of people like them. However,because of the strong market demand, overfishing and the marine environmental pollution,the natural resources of silver pomfret presented a trend of recession. To evaluate thegenetic diversity and structure of the silver pomfret population in the coastal regions ofChina and to investigate the resource management, protection and rational development isplaned. We discussed and analyzed the genetic diversity and population structure of thesilver pomfret using microsatellite markers.We constructed a (CA)12and (AG)12enriched microsatellite library using FIASCO(Fast isolation by AFLP of sequences containing repeats) method. And then, we obtained54sequences including microsatellite sequences.34pairs of primers were designed and weobtained13polymorphic microsatellite markers. Polymorphism of these markers wasassessed by PCR and SDS-PAGE technologies on30silver pomfret samples. The numberof alleles for each locus ranged from3to10, with an average of5.46, while effectivenumber of elleles ranged from2.71to9.23with an average of4.71. Observedheterozygosity and expected heterozygosity ranged from0.09to0.36and0.64to0.91,respectively. Significant deviation from Hardy–Weinberg equilibrium (HWE) was found atfour loci, which possibly was due to the presence of null alleles and the relation betweensamples. In a word, these microsatellite markers were the ideal molecular markers for thedetection and analysis of genetic diversity and population structure about different silverpomfret populations.Using the13polymorphic microsatellite markers, the genetic diversity and populationstructure from7populations (Zhoushan, Xiangshan, Ninghai, Yueqing, Qingdao, Rizhao,Qingdao) of the East China Sea, the Yellow Sea and the Bohai Sea were examined.Moreover, high level of genetic diversity was detected. The total numbers of observedalleles were71and the mean number was5.46per locus. The mean number of effectiveallele was4.91. The value of polymorphism information content (PIC) ranged from0.58to0.88. For the13polymorphic microsatellite loci, the results of AMOVA analysis indicated92.45%of the genetic variation contained within populations. The UPGMA cluster analysisrevealed that there were significant genealogical branches or clusters corresponding tosampling localities. It indicated that samples from Zhoushan, Yueqing, Xiangshan andWenling locations were obviously separated from the other three populations, Rizhao and Qingdao populations are separated from the Laizhou population. And the analysis by theSTRUCTURE software showed the same result and it also showed that a little infiltrationexisted in each other. This result might be likely due to the reason that the geographicisolation was not very strict and little partial mutual crosses existed in all of thepopulations.In conclusion, we could say there was high genetic diversity in these silver pomfretpopulations and the geographical isolation has a big impact on gene communication of thesilver pomfret populations. However, because of the incompleteness of geographic isolation,small part of gene communication exists in the same species from different sea areas.