[The mitotic activity of the cells in the head neural ganglion in larvae of the Drosophila ts mutant with an altered capacity for learning and augmented calmodulin activation properties].

Mitotic activity of head neural ganglion cells of Drosophila melanogaster larvae from two genetic stocks was studied. The mutant stock agts3 with augmented activatory potentialities of calmodulin and modified capacity for learning was compared with the control wild type Canton-S stock. The mitotic index was defined as the ratio of the number of cells in the state of division to the total cell number. The mitotic index was calculated after 30-min incubation of the larvae at the temperature of 37 degrees C and without heating under normal conditions (22 degrees C). At 22 degrees C the mitotic index in agts3 was higher than in CS. Exposure to 37 degrees C led to a sharp decrease of mitotic activity in both stocks. Increased mitotic index in agts3 stocks at 22 degrees C was probably connected with augmented activatory potentialities of calmodulin. After preincubation of the neural ganglions with calmodulin inhibitor trifluoperazine (10(-3)M) for 30 minutes the difference between the mutant and control stocks in mitotic index disappeared due to its approximately 3-fold decrease in agts3 stock. The obtained results supported the proposed hypothesis and demonstrated importance of calmodulin as a regulator of mitotic activity of cells from the neural ganglion of Drosophila larvae.