In most natural settings, cells do not face an isotropic environment. Rather, they see a spatially- and physically-structured landscape, which may have regions that vary in cell density, concentrations of nutrients, chemo-attractants and -repellers, substrate mechanics and chemistry, flow, pH, and temperature. These variations in environment are important determiners of biological functions in a wide variety of systems.
We presently have two projects to address two different types of spatial structure. In the first, we are looking at how the spatial arrangement of P. aeruginosa and S. aureus neighbors contributes to synergistic interactions between these two species. In the second, we are examining how the amphiphilic physical chemistry of autoinducers (molecules used for intercellular signaling and quorum sensing) affects signalling in amphiphilically-structured environments. For both of these projects, we use quantitative analysis of microscope images and a variety of sample preparation techniques.
In future, we will test our hypotheses about the importance of spatial structure by using laser traps to place cells at precise positions. We can controllably pattern cells of one or multiple types (two bacterial strains are shown at left, differentiated by color) to study the effects of neighbor arrangement and environmental patterning on cell behaviors such as motility, association, gene expression, and signalling.
For more information on this, please talk with Vernita.