Genetic Map Construction In Hypophthalmichthys Molitrix And Megalobrama Amblycephala

Construction of genetic map is one of the hot issues in the field of biological research. The present study use PCR( polymerase chain reaction ) and RAPD( random amplified polymorphic DNA) technique ,directly test the distribution of genes of the embryo of filial generations. We obtain the message about genetic linkage on every gene site, whereupon the genetic map of fishes can be constructed quickly and briefly. And this study provides a powerful tool for the analysis of fish genome structure and function including the detection of quantitative trait loci(QTL).Hypophthalmichthys molitrix and Megalobrama amblycephala. are two important fishes in aquaculture of our country. A molecular linkage map was constructed for the parents of Hypophthalmichthys molitrix and Megalobrama amblycephala in the research. A set of 100 random oligonucleotide primers were screened and 23 primers were selected to generate RAPD markers within a sample of 49 FI progenies. A total of 65 segregating loci were identified. Among the 65 loci, 3 loci were found distorted from the Mendel law. Using multiple analysis, the 62 markers formed 5 linkage group/pairs in Hypophthalmichthys molitrix (including 25 markers) and 6 linkage group/pairs in Megalobrama amblycephala (including 21 markers). The resulting Linkage map of Hypophthalmichthys molitrix spanned 538.IcM (61.7%coverage of genome length) with an average distance of 19.36cM between markers. And the resulting Linkage map of Megalobrama amblycephala spanned 438.8cM (44.5%coverage of genome length) with an average distance of 17.25cM between markers. A middling density genetic linkage frame was obtained in this research. It can be combined with the map that constructed by our Lab using the same population, and it supplies a linkage framework for a more saturated linkage map of Hypophthalmichthys molitrix. This map is a starting point for mapping some gene and quantitative traits loci linked with important economic traits about Hypophthalmichthys molitrix and Megalobrama amblycephala. It is an important step towards the molecular breeding in fishes.