IMAGE-ANALYSIS OF LYSOSOMAL ACTIVITY DURING THE EARLY CLONAL LIFE OF PARAMECIUM-PRIMAURELIA

Acid phosphatase activity was measured in individual cells by determin ing their optical densities through a scanning confocal laser microsco pe. The naphthol AS-TR (3-hydroxy-2-naphtoic acid 4'-chloro-2'-methyla nilide) phosphate-hexazotized para-rosanilin method was used to visual ise the acid phosphatase content in the light microscope. Evidence was obtained that the amount of enzyme varied in exponential growth phase cells as the fission age increased. By comparing the acid phosphatase activity with the rate of food vacuole formation, it appeared that th e amount of enzyme inside the cells decreased in early clonal life, wh ereas the rate of food uptake increased. It was assumed that the reduc tion of acid phosphatase content could lead to a more extended life of vacuoles and to a decreased membrane recycling rate. In turn, the red uced supply of membrane available for food vacuole formation could par tly be responsible for the decrease of the food uptake rate observed a fter the initial increase.