Biochemical Genetic Analyses of the Grass Carp ♀ X Bighead Carp ♂ F1Hybrid and the Parental Species

Abstract
The patterns of isozyme expression in tissues of the grass carp Ctenopharyngodon idella, bighead carp Hypophthalmichthys nobilis, and F1 hybrid (grass carp ♀ x bighead carp ♂) were analyzed by vertical starch gel electrophoresis and histochemical staining procedures. Both parental species and the F1 hybrid were fixed for electrophoretically indistinguishable alleles at 21 of 30 loci studied. However, the two parental species were fixed for different alleles at the remaining nine loci. Quantitative isozyme determinations were used to calculate the parental gene dosages in individuals of the 1979, 1980, and 1981 broods of F1 hybrids produced in Arkansas. Exclusive of low percentages of gynogenetic grass carp observed, the percentages of triploid F1 hybrids were 100% (1979), 44% (1980), and 100% (1981).