The Analysis Of The Genetic Diversity Of Different Populations Apostichopus Japonicas Using ISSR And COI Markers

Abstract Apostichopus japonicas Selenka is normally restricted to the shallow sea of the Northern Pacific. It belongs to Echinodermata, Eleutherozoa, Holothuroidea, Aspidochirota, Stichopodidae, Apostichopus. Some reports about the genetic diversity of some kinds of Holothuroidea have been seen in some both here and abroad articles but have none about Apostichopus japonicasby by using DNA molecular marks. Inter-simple sequence repeat (ISSR) and cytochrome oxidase subunit I (COI) gene were used to estimate genetic diversity and relationship in DNA of Apostichopus japonicas which belong to five districts, JD,JQ,CXD, DLJ,PK. Some biological analysis softwares such as POPGEN 32 and MEGA 3.0 were used to analysize the data. ISSR-PCR and COI-PCR reveal that five populations have the high genetic diversity. Among 12 ISSR primers, about 140 polymorphic genetic loci in 148 genetic loci were amplified. The total percentage of polymorphic loci of the five populations is 94.59%, and the average polymorphic genetic loci is 11.67. Index Nei is 0.2756, index Shannon is 0.4224. The coefficient of gene differentiation (GST) is lower than 0.5. These results reveal that the genetic diversity of these five populations is abundant, Gst (0.0507 in the average) has a small range of alteration, 0.0378~0.0706. These show that the gene differentiation is small among the five populations.The results show that the genetic diversity mainly presents within the populations not among the populations. It is gene flow that leads to the high genetic identity among the five populations. The analysis between one and another within the five populations indicates that the genetic diversity is abundant between one and another. Gst is 0.0706 and lower than it. This also shows that because of the affection of the gene flow, the genetic diversity mainly presents within the popula- tions not among the populations.Cytochrome oxidase subunit I (COI) gene analysis can also prove the genetic diversity mainly presented within the populations not among the populations.The PCR products were accumulated,purified and sequenced. As a result,377 bp nucleotide sequences of partial COI gene were obtained. By using biological analysis softwares to compare the sequences of these 25 individuals, 17 individuals have variation sites. 11 variation sites are polymorphic sites in the 26 variation sites. There are 22 transition sites, 2 transversion sites and 2 transi-tion-transversion sites. Nucleotide diversity (Pi) is 2.918% in the 17 individuals.The shows that the population has the high genetic diversity.The pairwise genetic distances were computed by MEGA 3.0. The NJ and MP phylogenetic tree were obtained through the cluster...