NON-RANDOM DISTRIBUTION OF CHROMOSOMAL-ABERRATIONS INDUCED BY 3 CHEMICALS

The G[Giemsa]-band locations of 3244 breakpoints induced by cis-platinum (II) diamminedichloride (PDD), 1460 breakpoints induced by cytosine arabinoside (ara-C), and 1257 breakpoints induced by triethylenemelamine (TEM) in human lymphocyte chromosomes were identified. The breakpoints induced by each of these chemicals demonstrated a significantly nonrandom distribution within the human karyotype. The overall pattern of the interarm distribution was dependent upon the chemical used, but certain chromosome arms exhibited similar responses to all 3 chemicals. Comparison of the frequencies of breakpoints within individual G-bands indicated that certain bands were susceptible to damage induced by all 3 chemicals; certain bands were resistant to damage by all 3 chemicals; certain bands demonstrated variable susceptibility to induced damage dependent upon the chemical agent; and other bands demonstrated near expected frequencies of damage (by length) to all 3 agents.