Hyperthermia and radiation-induced dominant lethals and chromosome loss in female Drosophila melanogaster.

The hyperthermia treatment, 38 degrees C for 1 hour significantly increased the dominant lethals induced by 1000R of X-rays in immature oocytes. The viability and chromosome loss in mature eggs were affected by either heat treatment or radiation. Hyperthermia treatment given before radiation exposure also significantly increased radiation-induced loss of the X chromosome in immature oocytes. Heat treatment did not increase radiation-induced nondisjunction of the chromosomes.