Linkage relationships of gene loci in the Medaka, Oryzias latipes (Pisces: Oryziatidae), determined by backcrosses and gynogenesis.
Linkage relationships of 11 enzyme loci and 2 visible mutant loci were investigated in the Medaka, Oryzias latipes, using backcrosses and gynogenesis. Results of four crosses for three loci were not in agreement with the Mendelian expectation of a 1 homozygote:1 heterozygote segregation ratio. Some locus pairs showed a significant excess of parental types at the 5% confidence limit. At the 1% confidence limit, however, results of all locus pairs analyzed showed nonsignificance. The results of sex-linked locus tests showed that no loci were sex linked at the 1% confidence limit. Under complete interference conditions, gene-centromere distances (cM) were as follows: Me, 2.6; Adh, 10; Sod, 17; Sdh, 18; Pgm, 31; Ck-A, 31; Gpdh, 32; Pgd, 45; Amy, 47; and Ldh-A, 50. High heterozygous fractions observed for Pgd, Amy, and Ldh-A suggest that exactly one crossover happened between these genes and their centromeres and that strong interference exists in chromosomes carrying these loci.
Zoological Institute, Faculty of Science, University of Tokyo, Japan.
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Naruse
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Shima
D000818:Animals; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D003532:Cyprinodontiformes / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D008040:Genetic Linkage; D009990:Oryzias / Q000235:genetics*; D011995:Recombination, Genetic