[The induction of chromosome loss and gain by colchicine (author's transl)]

The fruit fly Drosophila melanogaster is one of the standard systems used for mutagen screening. The colchicine-containing drugs Colchicum-Dispert and Colchysat Burger were fed at extremely low concentrations (1:300 000 and 1:50 000 respectively) to Drosophila females. Among their offspring a remarkably high frequency of aneuploid individuals (XO and XXY flies) were found. These aneuploids correspond karyotypically to the human Ullrich-Turner (XO) and Klinefelter's (XXY) syndromes and result from chromosome loss (XO) and chromosome gain (XXY). The maximum aneuploidy frequency observed after colchicine feeding was 24 times the control value. Depending on their size the aneuploidy frequencies are as great as those obtained by X-irradiation with some hundred or some thousand R.