Effects of induced pinocytotic activity and extreme temperatures on the morphology of Golgi bodies in Amoeba proteus.

The morphology of the Golgi apparatus of Amoeba proteus can be influenced by substances inducing pinocytotic activity as well as by extreme temperatures. During the ingestion of a solution of 0.5% egg white the number of Golgi bodies decreases from 100% measured in control cells to 82% measured in cells showing induced pinocytosis. Simultaneously the ratio of the surface area of the cisternae at the proximal face to that of the vesicles at the distal face of single dictyosomes remains constant (1.74-1.72). The decrease and increase of the temperature of the culture medium to 4 degrees C and 30 degrees C respectively, causes the disappearance of most of the dictyosomes. After keeping the cells for 3-10 h at these temperatures the number of Golgi bodies was only 5-10% of the controls. A continued treatment with cold or warm culture medium leads to a partial reorganization of dictyosomes. After 15 h the number of Golgi bodies counted per cell returned to 57% at 4 degrees C and 38% at 30 degrees C. The ratio of the surface area of the Golgi cisternae to the surface area of the Golgi vesicles also alters under the influence of extreme temperatures. The values measured after treating the cells for 3h, 4 h 10 h and 15 h at 4 degrees C and 30 degrees C amounted to 0.75, 0.85, 1.14 1.53 and 0.93, 0.38, 0.88, 1.60, respectively, compared to 1.72 of control amoebae. The different values of the ratio of the surface area of cisternae to that of vesicles indicate that there are strong morphological changes of single dictyosomes.