Genetic variation in different varieties of Siamese fighting fish using isoelectric focusing of sarcoplasmic proteins     

Gideon Khoo  Eric Y.F. Loh  Tit Meng Lim  Violet P.E. Phang 《Aquaculture International》1997,5(6):537-549

Sarcoplasmic proteins of four colour varieties of Siamese fighting fish, Betta splendens Regan, were analysed by isoelectric focusing (IEF). Genetic polymorphisms were detected in six loci having isoelectric points: 4.92-5.00 (Sp-1), 5.33-5.48 (Sp-2), 5.90 (Sp-3), 6.31-6.35 (Sp-4), 6.58-6.70 (Sp-5) and 6.90 (Sp-6). For the Sp-1, Sp-2, Sp-4 and Sp-5 loci, there were two co-dominant alleles. At Sp-3 and Sp-6, one allele was dominant and the other null. Individuals within each locus were classified into phenotypes A, AB and B. Only homozygotes were found at Sp-2. Allele frequencies were calculated for each locus and tested for accordance with the Hardy-Weinberg equilibrium. Observed values for each phenotype at Sp-1, Sp-3, Sp-4, Sp-5 and Sp-6 agreed well with the expected ones. At Sp-2, genotypic frequencies for each variety deviated markedly (p < 0.01) from the equilibrium. When tested for homogeneity, no significant differences (p 0.95) in gene frequencies were found among the varieties except at Sp-2. Band sharing index (BSI), computed using the BIO-GENE v5.04 program, revealed high intravariety genetic similarities (0.701-0.740) and slightly above-average intervariety values (0.550-0.583). In this study, we estimated the levels of genetic variability in B. splendens, and proposed a genetic model for each polymorphic locus.  相似文献