Investigating gradient sensing in cells through optical micromanipulation

摘要

The aim of our work is to develop new optical tools to quantify parameters that may enter into models of cell motion in response to chemical gradients (chemotaxis). Dictyostelium discoidium is a well-known model organism for studying chemotaxis. We have developed a technique for manipulating Dictyostelium cells directly using a holographic laser tweezer array. Using this technique we have perturbed crawling Dictyostelium cells by changing their direction of motion. After tens of seconds, the cells generate protrusions perpendicular to the rotated polarization as they reorient in the direction of the local cAMP gradient. Here we describe how such micromanipulation may be used to test proposed biochemical pathways and their connection to mechanical deformations.