TABLE 1

Frequencies of chromosome abnormalities in colchicine-arrested metaphases from mutant larval brains of the indicated genotypes

GenotypeNo. of cells scoredSTAsaDTAsaTotal TAsaBreaksb (%)Polyc (%)
nbs1/Df(3L)AC14459.721.230.9d10.4g0.3
nbs15337.1528.1435.3d13.1g3.6
rad50Δ5.166614.146.860.912.6g5.1
tefuatm658310.954.965.813.44.6
rad50Δ5.1 tefuatm668510.958.969.8e20.7h6.1
nbs1 tefuatm630916.182.598.7f33.0h6.1
rad50Δ5.1 nbs151016,583.399.8f14.5g5.9
mei4129D tefuatm614234.692.7127.4f14.57.7
mei4129D rad50Δ5.112014.7120.6133.5f38.4h3.8
mei4129D nbs120125.7102.3127.9f57.8h7.1
  • a Mean number of TAs observed in 100 metaphases.

  • b This class includes both chromatid and isochromatid breaks.

  • c This class includes both polyploid and hyperploid cells.

  • d These TA frequencies are not significantly different (Student's t-test).

  • e The frequency of TAs in this double mutant is not significantly different from those observed in single mutants (Student's t-test).

  • f The TA frequencies in these double mutants are significantly different from those seen in single mutants (Student's t-test, P < 0.01 in all cases).

  • g These frequencies of chromosome breaks are not significantly different (χ2 test).

  • h The frequencies of chromosome breaks in these double mutants are significantly different from those observed in single mutants (χ2 test, P < 0.01 in all cases).