Fine Structural Damage in the Somatic Tissues of Gamma-Irradiated House Fly. 1. 1 Flight Muscles

Abstract

Irradiation of male Musca domestica L. with gamma rays induced considerable changes in the fine structure of the fibrillar flight muscles. Within 4 hrs after irradiation with 10,000 rads, the sarcoplasmic and transverse tubular system showed vacuolation. The extent of vacuolation increased with increase in dose. These vacuoles disappeared in the 10,000- and 20,000-rads-irradiated groups by the 6th and 10th day, respectively, but remained in the flight muscles of flies irradiated with 40,000 rads. Damage to the flight muscle mitochondria became evident 2 days after irradiation with 20,000 and 40,000 rads. Disruption of the cristae was followed by loss of material from the matrix. Eighteen days after irradiation most of the mitochondria in the 20,000-rads-irradiated group appeared to have repaired this damage, whereas in the 40,000-rads-irradiated group the damage persisted, and many mitochondria contained whorllike structures. Moreover, the mitochondria showed accumulation of glycogen granules. The significance of these findings with respect to aging in the house fly is discussed.