Scambi di cromatidi fratelli e aberrazioni cromosomiche indotte dalla fusaproliferina nei cromosomi mitotici della capra (Capra hircus L.)

Severe teratogenic effects have been reported on chick embryos treated with 1-5 mM of fusaproliferin, a new toxic metabolite extracted from Fusarium proliferatum infected maize cultures. In order to understand the mode of action of this mycotoxin, sister chromatid exchanges (SCEs) and chromatid/chromosome breaks were studied on mitotic chromosomes of the goat (Capra hircus L.). Peripheral lymphocytes of the goat were treated with 0.5 microng/ml of BrdU as control and with a constant dose of 0.5 microng/ml of BrdU plus increasing concentrations of fusaproliferin, i.e. 0.05, 0.1, 0.2, 0.4 and 0.8 microng/ml. The results demonstrated SCE and chromatid breaks inducing effects of the substance. The mean rates of SCEs per cell were: 6.5 +- 1.2 in the BrdU-control cells, 7.6 +- 2.2 and 10.0 +- 3.1, respectively, at the lowest and highest dosages of fusaproliferin; the mean rates of chromatid/chromosome breaks per cell were: 0.53 +- 0.72 in the BrdU-control cells, 0.69 +- 0.78 and 0.93 +- 0.8, respectively, at the lowest and highest dosages of fusaproliferin. Chromatid breaks were preferentially induced compared to chromosome ones: in the BrdU-control cells (78 vs 22%, respectively), 82 vs 18% and 92 vs 8% at the lowest and highest dosages of fusaproliferin. The pronounced clastogenic action and the SCE-inducing effects demonstrated by fusaproliferin may, at least partially, explain the high level of teratogenic effects observed on chick embryos.