The effects of starvation and light on intra-mitochondrial granules in Physarum Polycephalum

Abstract

The presence of spherical or rod-shaped, electron-dense particles was noted within the mitochondrial cristae of Physarum polycephalum plasmodia. When sporulation was stimulated by starvation and subsequent illumination it was found that the numbers of such particles present per mitochondrion increased during the starvation phase, reaching a maximum after about 4 days, and then decreased rapidly during exposure of the plasmodium to light. Few particles were present in the mitochondria of spores. It is suggested that the particles may be similar to the mitochondrial granules of other organisms in providing a repository of calcium, which in Physarum is deposited in the capillitium during sporulation.