CHLORAL HYDRATE IS RECOMBINOGENIC IN THE WING SPOT-TEST IN DROSOPHILA-MELANOGASTER

In order to characterise the response of the wing spot test in Drosoph ila melanogaster to the effects of compounds with known aneugenic prop erties, experiments were performed with chloral hydrate (CH). Followin g chronic exposure of 72-h-old larvae to rising concentrations of CH, significant increases in the frequency of small (1-2 cells) single spo ts were observed. Comparison of results obtained in parallel from the wings of marker-trans-heterozygous individuals and individuals heteroz ygous for one of two different balancer chromosomes suggests that prac tically all the single clones originated from recombinational events. Twin clone frequencies were, however, only weakly affected. These resu lts are discussed with reference to the literature regarding the effec ts of CH in different experimental systems and to the characteristics of Drosophila as a tester organism.