Cysteamine Protection of Grasshopper Chromosomes from X-ray-induced Aberrations under Aerobic and Anaerobic Conditions

Summary

The effect of cysteamine pre-treatment on the frequency of x-ray-induced chromosome aberrations was determined under both aerobic and anaerobic conditions by counting the dicentric bridges in the first division meiotic anaphase of the grasshopper, Gesonula punctifrons. Under aerobic conditions in the cysteamine-treated animals 20·73 per cent bridges were scored as compared with 30–90 per cent in the controls. Under anaerobic conditions the scores were 5·35 per cent and 8·22 per cent in the treated and controls, respectively. Thus the degree of protection by cysteamine under both aerobic and anaerobic conditions was found to be more or less the same. The possible mode of protection has been discussed.