Genetic Diversity Studies In Natural Populations Of Engraulis Japonicus Of Dong Hai And Yellow Sea

Genetic diversity in three natural populations of Engraul isjaponicus col lected from our sea area of Dong Hai and Ye I low Sea was analyzed by using RAPD technique and DNA sequence.The randomly amplified polymorphic DNA (RAPD) technique has become a powerful genetic marker for estimating polymorphism within species and populations. The technique was used to examine genetic diversity in Engraulis japonicus from the three populations. Initially, 10 oligonucleotide primers (S101-S140; Sangon, Canada) were screened and 16 were selected to amplify genomic DNA from 60 samples representing these three populations. A total of143 DNA bands were scored among the three populations, and the frequency of polymorphism was accounted for 70. 62 percent. Shannon' s information index(H()) [Lewontin (1978)] of population 1> 2> 3 respectively was 0. 3453> 0. 343K 0.3441. The mean about genetic diversity indexes of three populations(Hpop)was 0.4318, and the genetic diversity index of all the population(Hsp) was0.4573. The genetic identity and distance showed that there were not significant differences in polymorphisms among the three populations, and the results show that 94.42 percent of genetic variation is distributed within populations and 5. 58 percent among populations.Mitochondrial DNA cytb gene (cytochrome b gene) fragment was amplified with PCR and sequenced, 420 base-pairs nucleotide sequences of 46 simples from three populations were examined and analyzed for genetic polymorphism, 15-?16, 15 samples apartly for population 1, 2, 3. Data analysis indicated that there were 24 variable positions and all 46 nucleotide sequences were grouped into 29 haplotypes. Population 1 showed more variation positions than others, nevertheless Population 3 showed more haplotypes than others. On the three indexes of nucleotide diversity (Pi), number of polymorphic sites (SX average number of nucleotide differences (A), Population 1 showed more larger than others. But no significant genetic differentiation was observed among these populations.The data provide much information on the genetic variation in natural populations of Engraulis japonicus, and it will be useful to further studies in genetic analysis on Engraulis japonicus populations . Maybe it is also useful for future management and utilization of the resource.