Griseofulvin

Aneuploidy in Drosophila, II. Further validation of the FIX and ZESTE genetic test systems employing female Drosophila melanogaster

Two sensitive genetic systems for the detection of germline aneuploidy employing Drosophila melanogaster females were described in the first paper of this series (Zimmering et al., submitted to Mutation Research). Designated FIX and ZESTE, these systems permit the rapid and efficient detection of exceptional offspring derived from aneuploid female germ cells. The current report presents test results from a survey of 8 additional chemicals that have been analyzed in both systems. The tested chemicals include: acetonitrile, cadmium chloride, carbendazim, dimethylsulfoxide (DMSO), methylmercury(II) chloride, methoxyethyl acetate, propionitrile and water. Excluding the negative control, water, only the fungicide carbendazim failed to induce aneuploidy in either test system. Of the remaining 6 chemicals one, methylmercury(II) chloride, was positive in the FIX system but not in ZESTE, while MEA was positive in ZESTE and borderline in FIX. The results provide little evidence of germ-cell stage specificity of response to the tested chemicals. Comparison of the induced rates of aneuploidy i indicates that these can exhibit departures from simple additivity to the spontaneous rates: induced rates in the ZESTE system are generally higher and more variable than those from FIX. Possible reasons for the difference in responsiveness between FIX and ZESTE flies are discussed as is the question of the classification of those chemicals which induce chromosome loss events but not chromosome gains.

Aneuploidy in Drosophila, I. Genetic test systems in the female Drosophila melanogaster for the rapid detection of chemically induced chromosome gain and chromosome loss

An account is provided of two genetic schemes in the Drosophila melanogaster female designed as rapid detectors of chemically induced aneuploidy, including both chromosome gain and chromosome loss. One scheme is referred to as FIX, in which the female carried free (heterozygously) inverted X (chromosomes) and the other, ZESTE, where females do not carry inversions and the X-linked sexually dimorphic zeste mutation plays the key role in the detection of aneuploid offspring. The principle attribute of the FIX system is that all euploid offspring are wild-type for body and eye color whereas aneuploid females have a yellow body and aneuploid males white eyes; int he ZESTE system all euploid individuals are wild-type for eye color, aneuploid females possess zeste-colored eyes and aneuploid males white eyes. In addition induced polyploidies (2X:2A gametes) appear as yellow and zeste male intersexes in the FIX and ZESTE systems, respectively. In this way all aneuploids are recognized immediately. Consequently, detection of compounds with weak effects requiring large sample sizes may be made in a fraction of the time associated with more traditional schemes for aneuploidy detection in Drosophila.