[Mobile elements of the Drosophila genome as a marker of crossing over in isogenic crosses with a balancer strain].

The ability of the Cy/Pm; D/Sb balancer strain to inhibit crossing over in isogenic crosses was studied. Regions of interchromosomal exchange were detected within and outside the inverted regions with the help of the MDG1, Dm412, copia, and B104 mobile elements. Certification of mobile element distribution patterns in balancer strains was proposed. Crossing over was suggested as a possible reason for the polymorphism of daughter strains and as useful for estimating frequency of transposition of mobile elements in similar interstrain crosses.