Chapter 50 - Use of Brain Cytosolic Extracts for Studying Actin-Based Motility of Listeria monocytogenes

Abstract

This article discusses the use of brain cytosolic extracts for examining actin-based motility of listeria monocytogenes. Cell motility is essential for numerous biological events. Unicellular organisms, for instance, use directed movement to find and ingest food. As one approach toward defining the molecular basis of bacterial motility, researchers have developed simple in vitro systems that support actin-based Listeria motility based on Xenopus, platelets, and mouse brain extracts. One needs to kill mice using carbon dioxide or by cervical dislocation. One then needs to remove skin and fur from the head using thin-tipped scissors and discard. Wash bacterial pellet three times in homogenization buffer. After the final washing step, resuspend pellet in a final volume of homogenization buffer corresponding to the initial volume of bacterial culture. Although cell-free systems based on egg extracts of Xenopus laevis or human platelet extracts provide excellent in vitro systems for supporting actin-based bacterial motility, their ability to do so can be affected negatively by various factors, such as health of eggs or quality and age of platelet preparations.