Development Of Microsatellite And Construction Of Genetic Linkage Maps Of Olive Flounder (Paralichthys Olivaceus)

Olive flounder(Paralichthys olivaceus) is one of economically important fish in China.It is distributed widely over the Bohai Sea, the Yellow Sea and the South Sea in China, North Korea,Japan and along the east coastline of Russia.As its natural resource is exhausting gradually, olive flounder has become an important cultured fish in China. Polymorphic available DNA markers are needed for its genetic research.This dissertation consists of two sections:The first one is the construction of microsatellite-enriched genomic library of Paralichthys olivaceus based on FIASCO method.191 microsatellite sequences is obtained separately through screening and sequencing. The perfect, imperfect and compound microsatellite sequences take up 74.70%,14.71% and 10.59% separately. The method of FIASCO modified in the present study is efficient and low-cost choice for the isolation of microsatellite in marine fish species.The second section is the construction of genetic linkage map of Paralichthys olivaceus. This genetic linkage map is constructed by using only microsatellite loci. 1000 novel microsatellite markers for Japanese flounder, Paralichthys olivaceus were selected from a microsatellite-enriched library constructed by genome sequencing. The 10th population with 80 individuals, crossed by 6812E36 as female parent and 681383B as male parent were used in this experiment.256 SSR primers were screened with the two parents and amplified on the 80 individuals. The total length of the integration genetic map is 1465.3 cM, and the average distance among markers is 5.7 cM. The length of linkage group varied from 13.7 cM to 106.6 cM, and the markers on the linkage group varied from 3 to 26. The distribution of SSR markers on every linkage group is not even. High density region of markers existed on linkage group 1, 3 and 4.This linkage map may be helpful for MAS (molecular marker-assisted breeding),quantitative trait loci (QTL) mapping and construction of middle or high density linkage map of Paralichthys olivaceus.