title: Genetic analysis of enzyme polymorphisms in plaice (Pleuronectes platessa).
abstract: Genetic analysis was performed on five enzyme systems (G3PDH; GPI-A; GPI-B; PGM; MDH-A) in plaice (Pleuronectes platessa) collected in spawning condition from the North Sea. Conventional crosses, induced gynogenesis and induced triploidy were performed. The data conclusively demonstrated the inheritance of isozymes by co-dominant alleles at individual loci for each system. No linkage was observed but tests did not include MDH nor the possibility of linkage between G3PDH and GPI-A. Some anomalous segregation ratios were observed, particularly a deficiency of heterozygotes for GPI-A, but the data were largely in conformity with Mendelian expectations. At the PGM locus, five independent anomalous individuals were scored and interpreted as mutations with a mutation rate of 1.1 X 10(-3) per gamete. Recombination with the centromere was assessed and induced triploidy and cross-over values of 41 per cent for PGM, 19 per cent for MDH-A and 9 per cent for GPI-B were derived on the assumption of complete interference. Amongst the parent fish, genotypic and phenotypic frequencies were largely consistent with the expectations of the Hardy-Weinberg Law, and allelic frequencies were not significantly different between year of collection or location of collection ground.
mesh_terms: D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D005399:Fishes / Q000378:metabolism*; D005796:Genes; D005799:Genes, Dominant; D005956:Glucose-6-Phosphate Isomerase / Q000378:metabolism*; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008297:Male; D010733:Phosphoglucomutase / Q000378:metabolism*; D011110:Polymorphism, Genetic
chemical_list: D008291:Malate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005956:Glucose-6-Phosphate Isomerase; D010733:Phosphoglucomutase