Chromosomal aberrations and frequency of micronuclei in sheep subchronically exposed to the fungicide Euparen Multi (tolylfluanid)

We analyzed chromosome aberrations, micronucleus frequency, mitotic index (MI), and nuclear division index (NDI) in peripheral lymphocytes of sheep subchronically exposed to the fungicide Euparen Multi (containing 50% tolylfluanid). Euparen Multi was administered by rumen sonde to group of Merino sheep (seven sheep/group) at 93 mg/kg body weight (1/20 LD50) daily for 28 days to assess its genotoxic effects. The frequencies of aberrant cells (ABC) in the experimental and control groups were 5.50±1.38% and 2.40±1.14%, respectively, and the increase in ABC in the treated group was significant (P=0.003). Significantly increased numbers of chromatid breaks (5.67±1.21% against 2.40±1.14%; P=0.001), chromatid gaps (10.33±2.73% against 4.00±1.23%; P=0.001), and chromosome gaps (1.83±0.75% against 0.80±0.45%; P=0.025) and exchanges (3.17±1.94% against 0.20±0.45%; P=0.009) were observed in exposed animals in comparison to control animals. The frequency of micronuclei (MN) was 29.40±5.86 per 1000 binucleated cells in peripheral lymphocytes of sheep in the control group and 49.57±19.12 per 1000 binucleated cells in the treated group. A significant increase in the frequency of MN in peripheral lymphocytes also was observed between the two groups (P=0.0477). No statistical differences in MI and NDI values were found in the groups (P=0.181 and 0.761, respectively). Thus, our results suggest that exposure to Euparen Multi may cause genome damage in somatic cells.