DNA-FINGERPRINTING CONFIRMS ISOGENICITY OF ANDROGENETICALLY DERIVED RAINBOW-TROUT LINES

Homozygous and hybrid clonal lines of rainbow trout (Oncorhynchus myki ss) were confirmed to be isogenic using multilocus DNA fingerprinting, Homozygous clones were produced by androgenesis and gynogenesis using gametes from androgenetic male and female rainbow trout, respectively . Isogenic F-1 hybrid lines were produced by crossing homozygous fish from different strains. One line of hybrid clones showed segregation f or maternally inherited DNA fingerprint markers. The female from this cross, the only presumptive homozygous gynogenetic individual used in this study, was thought to have been produced by gynogenesis followed by blockage of the first cleavage division, but based on the DNA finge rprint analysis, apparently was derived by spontaneous polar body rete ntion that maintained heterozygosity at some loci. Mutations at DNA fi ngerprint loci were not observed, indicating relative stability of fin gerprint loci in the clonal lines. DNA fingerprinting appears to be a useful tool for identifying and genetically monitoring clonal lines of rainbow trout. Isogenic lines of rainbow trout will facilitate the pr oduction of saturated genetic maps for rainbow trout and enhance such endeavors as quantitative trait locus (QTL) analysis and loss of heter ozygosity (LOH) studies in tumors.