The Feature Of Microsatellite On Three Culterinae Fishes And The Genetic Analysis Of Megalobrama Terminalis In The Pearl River

The study was divided into two parts, the first part was analysis the feature ofmicrosatellite on three culterinae fishes in the Pearl River, while the second part wasuse microsatellite markers to analysis the genetic diversity of Megalobrama terminalisin six bream populations of Pearl River.Microsatellite markers were used to distinguish Megalobrama terminalis,Parabramis pekinensis and Culter recurviceps in the Pearl River. Using genomic of M.terminalis, P. pekinensis and C. recurviceps as templates, PCR amplification wereperformed using108pairs of primers which were designed based on culterinae fishesmicrosatellite markers selected from GenBank and literature,16special microsatellitemakers were selected through PAGE glue. The result showed that, the maker F-524could PCR an amplified DNA fragment between309-320bp in M. terminalis and P.pekinensis; the maker L-4could PCR an amplified DNA fragment between160-201bpin C. recurviceps and P. pekinensis; the maker L-7could PCR an amplified DNAfragment between160-190bp in M. terminalis and C. recurviceps, also it could PCR anamplified DNA fragment between123-143bp in P. pekinensis. Using a specific markeralone or combination several specific markers together we can quickly identify thesethree species on molecular level, and these method could solve the problem that theearly growth of M. terminalis, P. pekinensis and C. recurviceps were almost the sameand couldn’t identify them through morphological.Ten microsatellite loci was used to analyze the Genetic diversity in six groupsof Megalobrama terminalis from Beijiang, Dongjiang, Tanjiang, Zhujiangkou,Wuzhou and Zhaoqing of Pearl River System. The following parameters were calculated numbers of alleles, polymorphic information content (PIC), heterozygosity,genetic distance, genetic similarity coefficient, Hardy-Weinberg balance deflectionindex, index of genetic differentiation among populations and other parameters.Results show that the average number of alleles in six groups was2.8479; thepolymorphic information content (PIC) of polymorphic loci varies was between0.2771-0.3226. the average expected heterizygosity (He) was from0.2598to0.3226,the average observed heterozygosity (Ho) was between0.2306-0.4043, among all thegroups the Tanjiang groups had the highest average expected heterozygosity which was0.4260, while the Zhaoqing groups had the lowest average expected heterozygositywhich was0.3598, these mean that Tanjiang group has the highest genetic diversity,whereas Zhaoqing group has the lowest genetic diversity. The genetic distances amongsix populations ranged in0.0110-0.1111and the genetic similarity coefficient of sixpopulations of Megalobrama terminalis was between0.8949and0.9891. Whenapplying Hardy-Weinberg equilibrium test, some loci of six populations were found tobe significantly from Hardy-Weinberg equilibrium. The genetic differentiation index(Fst) of six populations ranged0.0098to0.0876, this revealing a low level of geneticdifferentiation among the six groups. The UPGMA tree indicated that Tanjiang andDongjiang groups was respectively clustered into a branch, while the stocks fromBeijiang, Zhujiangkou, Zhaoqing and Wuzhou were in one cluster.