Study Of Microsatellite Markers On Population Genetics And Artificial Gynogenetic Stocks Of The Left-eyed Flounder, Paralichthys Olivaceus

Population genetics of the left-eyed flounder, Paralichthys olivaceus (T. & S.), including natural and cultured slocks of Shandong coastal waters of China was assessed using microsatellite markers. The genetic variations and the recombination rates between microsatellite markers and the centromere of meiogynogenetic offspring were also analyzed. In the meantime, a microsatellite-centromere mapping was constructed with the data depriving from the meiogynogenesis and mitogynogenesis stocks. The linkage relationship between microsatellite loci can be obtained from the mitogynogenesis stock. The main results shown as follows:1. The genetic variations of the natural and cultured stocks of Paralichthys olivaceus were assessed at 10 microsatellite loci (Pol, Po13, Po33, Po35, Po42, Po48, Po56, Po89, Po91, Po-strl). All loci are polymorphism. The average number alleles of per locus were 6.7 and 6.1, and the number of effective alleles (ae) of each locus in the natural and cultured stocks was 1.8-6.8 and 2.5-6.7, respectively, and The value of average heterozygosity (H) were 0.8120 and 0.7310. Genetic similarity (I), genetic distance (D) and coefficient of gene differentiation (Gst) between these two stocks were 0.8558, 0.1557 and 0.0558, respectively.The value of polymorphism information content (PIC) , power of discrimination (DP) and probability of paternity exclusion (PPE) were 0.59-0.84,0.54-0.86 and 0.41-0.72 at the 10 loci of the natural stock, respectively. The results indicated that the 10 microsatellite loci to be selected were very sensitive and could be used in the parentage and kinship determination of the artificial gynogenetic stock of left-eyed flounders and further genetic breeding study.2. Ten above polymorphism microsatellite markers were used to detect the genetic variations of the meiogynogenesis stock. There was no amplified product atPo91 locus because of the existence of null allele. Two loci (Po33 and Po48) were monomorphic and the rest were polymorphic in this stock. The mean proportion of polymorphic loci and the average heterozygosity were 77.8% and 0.3856, respectively. Compared with results of population genetics study, the genetic variation level of meiogynogenesis stock was lower than those of the natural and cultured stocks.Recombination was observed at the 7 polymorphic loci and the recombination rates between microsatellite locus and centromere were 42.6—100%, respectively. The results indicated that there was higher heterozygosity in the first meiogynogenetic generation owing to crossover between the homologous chromosomes during the meiosis-1 .3. Among the 20 loci used in the study on genetical analysis of meiogygenesis and mitogynogenesis stocks. A microsatellite-centromere mapping was constructed using the data depriving from the meiogynogenesis stock. The genetic distance between kopl5, Po42, Pol and the centromere was 15.8cm, 28.9cM and 32.4cM, respectively. The distance between the rest loci and the centromere was nearly 50cM, respectively.The linkage relationship between microsatellite loci were from the mitogynogenetic offspring's allele separation pattern. Po13 and Po56, Po91 and kop18, kop15 and kop21 are linkage.