Parallel monitoring of mitotic recombination, clastogenicity and teratogenic effects in eye tissue of Drosophila

Loss of heterozygosity (LOH) of the wild-type allele by structural chromosome aberrations (SCAs), homologous mitotic recombination (HMR) or intra-chromosomal (deletion/amplification) recombination (ICR) plays a crucial role in multistage carcinogenesis. We describe here an in vivo system, enabling the detection of all three chromosome breakage-related events in the same genetic experiment, with eye tissue of Drosophila as targets. This modification of the white/white(+) system enables to measure, simultaneously, HMR and ICR on the X-chromosome, and loss of a ring-shaped X-chromosome, utilizing the eye color gene white. Optimal conditions for the detection and quantification of SCAs (ring-X loss) compared to HMR are discussed in detail. Emerging new techniques comprise the parallel detection of HMR on chromosomes X and 3, using the tumor suppressor gene warts in addition to the X-linked marker white. Another modification of the white/white(+) system measures, again in parallel, HMR and chromosome duplication (non-disjunction).