THE RESPONSE OF YEAST CELLS TO A CHANGE IN THE DIRECTION OF A PHEROMONE GRADIENT IN A MICROFLUIDIC DEVICE

摘要

We have developed a microfluidic device that can produce stable pheromone gradients and rapidly rotate them in 90° increments, mimicking the dynamic gradients that yeast are exposed to in situ, and allowing for the study of reorientation as well as initial orientation. The mean angle of orientation exhibited by gradient-stimulated yeast cells in this device was 56. 9°. In control experiments, cells subjected to pheromone coming from all four directions showed no evidence of orientation. Switching the direction of the pheromone source by 90° induced 83. 6% of the polarized cells to change their direction of growth. Of these, 85. 2% bent their mating projections toward the second source, demonstrating the utility of this device in the study of reorientation.