TABLE 1.

Spontaneous and MMC-induced chromosome aberrations

Aberration type and genotypeaNo. of aberrations/100 cells% of cells with the following no. of aberrationsd:
ChromatidChromosomeChromatid exchangesTotal
BreaksGapsBreaksGaps012
Spontaneous
    Wild typeb0.31.00001.398.71.30
    fancgb0.60.300.301.398.71.30
MMC induced
    Wild typec
        20 ng/ml5.05.02.03.01.51784160.5
        40 ng/ml205.51.01.502873270.5
    fancgc
        20 ng/ml107.52.04.51.52676231.5
        40 ng/ml30132.02.00.54758394
  • a For the MMC-induced aberrations, the MMC concentration is indicated.

  • b A total of 300 metaphases were scored.

  • c A total of 200 metaphases were scored.

  • d No cells contained more than two aberrations.