Structure Analysis Of MtDNA D-Loop Region And The Genetic Diversity Of Channa Argu

In this study C. argu was sampled from Baiyangdian in Hebei province, Pingyuan countyin Shandong province and Dongting lake in Hunan province respectively between September2012and November2013. In total,104individuals fish were sampled from Baiyangdian,Pingyuan county and Dongting lake,64cultured population were sampled from Baiyangdianand Pingyuan country. After the total DNA extraction and PCR amplification,168mitochondrial control sequences of C. argu were sequenced. C.argu’ mitochondrial DNA wasretrieved from GenBank database and compared with the amplification sequence, thestart-stop sites of the D-Loop region of C.argu’ mitochondria were seek out. The result showsthat the sequence length of the D-Loop region of C.argu’ mitochondria is905-908bp and hasmeio-differentiation. terminator sequence area, Central Domain area and conserved sequenceof the D-Loop region of C.argu’ mitochondria were identified. This study also indicate thesubject of terminate the relevant sequence is TACAT and the reverse complementary sequenceis ATGTA and a series of conservative sequence（CSB-F、CSB-E、CSB-D�'�CSB-1、CSB-2、CSB-3）。Check experiment of C.argu wild population and cultured population in Baiyangdian andPingyuan county showed that genetic diversity of wild population was below culturedpopulation in both region. wild population and cultured population in Baiyangdian were twomaternal origins and appeared large genetic differences. wild population and culturedpopulation in Baiyangdian appeared small genetic differences and revealed the closerelationship between the two groups.Genetic diversity of three geographic population of C. argu showed that Dongting lakegroup> Pingyuan county group> Baiyangdian group. Nucleotide diversity between and withinthese tree groups were all below0.005and indicated low nucleotide diversity. Parametersrelated to genetic diversity of Baiyangdian group was lowest which declared the geneticdiversity within Baiyangdian group was poor. Genetic distance between and within these treegroups was0.00328, genetic distance between these tree groups was smaller and the value was between0.001to0.005, which indicated a close genetic relationship between3wildpopulations. The variation percentage of C.argu3wild populations were calculated throughAMOVA analysis. The variation percentages between and within groups were31.91%and68.09%respectively. The variation percentages within groups was significantly greater thanthe variation percentages between groups, which demonstated the vast majority of geneticvariation occurred within groups, not between groups. Phylogeny showed haplotypes did notclustered in accordance with the group of haploid type classification and part of thephylogenetic tree branch support is relatively lower, characterized by different groups withindividual interlaced form complex cluster, the main reason was branch internal nucleotidedifferences level is relatively lower, which also declared the differentiation between thegroups was not obvious. Tajima’s and Fu’s detection were used to test whether species duringevolution follow neutral evolution pattern or not. Values between different groups andindividual groups were all reached significant level. That illustrated both3groups did notexperience group augmentation and sustainable growth model and keep a stable populationsize.