The Analysis Of The Genetic Diversity Of Different Populations Of Neptunea Cumingi Crosse Using SSR Marker

Content:Neptunea cumingi Crosse belongs to phylum Mollusca,class Gastropoda, subclass Prosobranchia Buccinidae,genus Neptunea.It mainly distributed into coast of Liaoning and Shandong Province from China.DNA molecular marker is able to express genetic information accurately for its excellence of stability, accuracy and security.In this paper,simple sequence repeat(SSR) was used to study genetic diversity and relationships of Neptunea cumingi Crosse which distributed into five areas,Shandong,Donggang,Zhuanghe,Changhai and Lvshun in China.There were some studied about Buccinidae both in and abroad by using DNA marker,but none about Neptunea cumingi Crosse.Among thirty-three pairs of primers,three pairs were mononorphic,eight pairs were polymorphic and avaliable.Nighty-four individuals of Neptunea cumingi Crosse from five populations were analyzed by using the eight available SSR primers.SSR banding patterns were transformed into binary data and matrices were processed by Arlequin program.Using the data obtained,the genetic diversity and the genetic structure were estimated,the similarity coefficient was calculated and UPGMA and NJ clustering were analyzed on five populations of Neptunea cumingi Crosse.With the test of polymorphism for SSR maker,the allele numbers ranged from two to four,and observed heterozygosity ranged from 0.173 to 0.865 across populations.There was a trend of heterozygosity excess in all the populations detected by SSR technique,with the observed heterozygosity and expected heterozygosity were 0.594 and 0.518,respectively. Genetic distance among the five populations ranged from 0.008 to 0.164,and genetic identity ranged from 0.858 to 0.992.By the data of AMOVA,the percentage of variation among populations is 3.334%and within individuals is 95.516%,it represents that most of the variation exsisted within individuals of all five populations. The higher values of heterozygosities and proportions of polymorphic loci of the five populations indicated that there was an available condition with higher genetic diversity.Four phylogenetic trees of five populations suggested that,like the genetic distances,Donggang,Changhai,Zhuanghe,Lushun were closer to each other,and they were clustered together as the first group,SD was clustered into the second group.It represents that among populations of farther geographic distance, less Nm occured,lower the genetic differentiation happens and lower the genetic identity formed.