| Population genetics of the left-eyed flounder, Paralichthys olivaceus, including natural and cultured stocks off Shandong coastal waters of China was analyzed using isozyme and RAPD techniques. And partial DNA sequences of mitochondrial DNA 1 6S rRNA gene from P. olivaceus, Pseudorhombus cinnamomeus, Psetta maxima and Kareius bicoloratus were amplified by PCR and sequenced in order to address the phylogenetic relationships of 4 flatfishes. The main results shown as follows: 1. Pm and 25 isozymes, such as LDH, MDH, MEP, IDHP, G3PDH, AK, CK, ACP, PGM, SDH, ADH, CAT, SOD, GDH, GPI, GAPDH, ALP, HK, G6PDH, PGDI-1, MPI, EST, POD, AMY and GOT in 4 buffer systems (TC, pH=6.9; TCI,pH8.O; EBT, pH?.9; TG,pH=8.3) were studied by horizontal starch gel and vertical po]yacrylamide gel electrophoresis. Among them, 15 isozymes (LDH. MDH. MEP. IDHP.. G3PDH. AK.. CK. ACP, PGM. SDH. ADHS CAT.. SOD.. GDH.. GPI) in 3 buffer systems (TC, pH=6.9; EBT, pH=8.9; TG,pH=8.3) were analyzed, and their expression in 6 tissues and organs-tissues specify were also compared. The basic electrophoretic patterns of these 15 isozymes were gained and their biochemical genetic parameters such as locus number, structure, alleles et al., were also analyzed. The electrophoregrams of the rest isozymes were too bad to be recorded. 2. The natural sample size was 79 live left-eyed flounders, which were collected from the coastal waters of Qingdao. The cultured samples (52 live left-eyed flounders) were collected from a fish farm in Rongcheng of Shandong Province, the parental generation of which was also captured in the coastal waters of Shandong. The biochemical genetic structures of both stocks have been studied and compared. Altogether 29 loci in each stock were recorded, among them 9 gene loci (Ldh-A, Ldh- C, Idhp-1, Acp-1, Pgm, Sdh, Adh, Cat and Gdh) belong to the polymorphic loci in the natural stock and its mean proportion of polymorphic loci (P) was 31.0%. While in the cultured stock, 7 gene Joci (Ldh-A, Ldh-C, Idhp-1, Sdh, Adh, Cat and Gdh) belong to the polymorphic loci and its P was 24.1%. The allelic frequencies of both stocks were also gained, with the average heterozygosities (H) of stocks being 0.0802 in the natural stock and 0.0788 in the cultured stock. Both values ofF and H in the cultured stock are lower than those in the natural stock. The chi-square test showed that all polymorphic loci but Cat (P<0.05), Idhp-1 (P<0.05, only in the cultured population) and Ldh-C (P<0.0 1) in both of the natural and cultured stocks were in Hardy-Weinberg equilibrium. The observational values of heterozygosity (Ho), Hardy-Weinberg expected heterozygosity (He) and the genetic departure index (d) also expressed the difference in genetic variance of these two stocks. The genetic similarity and genetic distance between the two stocks were 0.9877 and 0.0 124, respectively. 3. 20 natural individuals and 24 cultured individuals of]? ollvaceus were investigated using 11 random primers, respectively. 88 and 86 RAPD bands ranging from 200 to 2,500 bp were recorded separately, an average of 7.8-8.0 bands gained by per primer. The mean percentages of polymorphic loci of two stocks were 43.2% and 34.9%. The average heterozygosity (H) of them were 0.2739 and 0.2255. And the average Shannon indices of phenotypic diversity of them (H0) were 0.1120 and 0.0942. The genetic similarity ano genetic distance between these two stocks were 0.9505 and 0.0508 respectively.
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