Induced cytoskeletal genes and the genes required for actin-based motility. (a) Cytoskeleton-related genes present on 24K arrays which respond to the infection with at least a threefold change. (b) Named genes known to be involved in actin-based motility of L. monocytogenes. Image contrast is set at 2, such that the brightest red is greater than a fourfold change. Gray spots indicate missing data. Note that genes previously known to be involved in actin-based motility are not specifically induced by wild-type bacteria.