A multivariate approach to the association pattern of reciprocal translocations induced by chemicals and ionizing radiation in mouse germ cells

The degree of similarity between chemical and physical agents in their capa city to induce reciprocal translocations was analyzed by means of multivari ate analysis techniques. The effect of three different doses of gamma rays, four doses of X-rays and different doses of adriamycin, mitomycin C, thio- tepa and bleomycin was analyzed. Data were arranged in a basic matrix by tw o methods: cluster analysis and ordination. Two main groups were found, one including doses of 9 and 10 Gy and the other including the remaining lower doses of ionizing radiation and the other chemicals. Various subgroups wer e found within the second group. Accordingly, using presence/absence data t here was not a specific pattern of chromosomal damage induction for physica l and chemical agents. The increase in the frequencies of reciprocal transl ocation observed with 9 and 10 Gy was due to an increase in the kind of mul tivalent configurations. This Variability could be dose dependent. Likewise , the similarity observed in the second group between the chemicals and the lower doses of ionizing radiation could also be dose dependent.