A Comparative Study of Mitosis in Amoebae and Plasmodia of the True Slime Mold Didymium nigripes

SYNOPSIS. Studies comparing mitosis in amoebae and plasmodia of the true slime mold Didymium nigripes reveal that at the time of differentiation pronounced changes occur in the mitotic process. Not only does the amount of time required for division of the 2 stages differ, but plasmodial mitosis is characterized by persistence of the nuclear membrane and the apparent lack of centrioles. The origin of multinucleate plasmodia from uninucleate cells which have already undergone cytoplasmic differentiation is described. Division time in a population of amoebae becomes more uniform after those cells which are destined to form plasmodia have differentiated.
The observations and data presented indicated that differences in mitotic behavior also occur between amoebae of 3 stocks with differences in plasmodial structure and behavior. Comparison of mitosis in the plasmodia of these 3 stocks revealed no significant differences.