F. Marchetti et al., DOSE-RESPONSE STUDY AND THRESHOLD ESTIMATION OF GRISEOFULVIN-INDUCED ANEUPLOIDY DURING FEMALE MOUSE MEIOSIS-I AND MEIOSIS-II, Mutagenesis, 11(2), 1996, pp. 195-200
The relative sensitivity of the two meiotic divisions of mouse oogenes
is to griseofulvin (GF)-induced aneuploidy was investigated. The first
meiotic division was studied by administering GF 4 h after human chor
ionic gonadotrophin (HCG) injection and analyzing metaphase II (MII) o
ocytes, whereas study of the second meiotic division involved treating
the females 10 h after HCG and analyzing one-cell (1-Cl) zygotes, Dat
a from previous studies have shown that these treatment times represen
ted the most sensitive times for aneuploidy induction during meioses I
and II. The statistical analyses of the data showed that the dose-res
ponse curves for aneuploidy induction did not differ quantitatively or
qualitatively between the two meiotic divisions. The percentages of h
yperploid MTI oocytes and 1-Cl zygotes were significantly higher (P <
0.001) than in the controls for all doses except 125 mg/kg GF. The hig
hest percentages of hyperploid cells were found after administering 15
00 mg/kg GF, However, these percentages were not different (P > 0.05)
from those observed after 500 or 1000 mg/kg GF, suggesting saturation
of the GF aneuploid target(s), These results suggest that the relative
sensitivity to GF-induced aneuploidy between the two meiotic division
s of oogenesis are similar. They also suggest the presence of a lower
(125 mg/kg) and an upper (500 mg/kg) threshold for GF-induced aneuploi
dy.