Welcome to the Shaw Lab
The Shaw laboratory studies how the microtubule cytoskeleton organizes and influences cellular morphogenesis. We focus on the interphase microtubule arrays in Arabidopsis plants as a model for understanding how cells generate ordered patterns out of apparent chaos. If the randomly arranged microtubules in a growing plant cell organize into a co-aligned array, like hoops around a barrel, the cell will elongate into a rod shape instead of a sphere. The influence of the microtubules comes as a result of their ability to organize and reorganize in response to spatially defined cellular cues. The fundamental mechanisms by which the microtubules recognize the cell axis, become co-aligned, and alter the cell wall properties to influence cell expansion are not yet known.
Using live-cell imaging techniques, computer simulation studies, and the powerful genetic tools available in the Arabidopsis system, we are discovering how the dynamic properties of the microtubule cytoskeleton contribute to the morphogenesis of the cell. Our discovery that cortical microtubules reposition themselves through polymer treadmilling has dramatically reshaped the hypotheses for array organization. Microtubule polymers in the plant cortical array 'move' when tubulin subunits bind to one end and concordantly unbind from the other. This remarkable mechanism leads to microtubule interactions and other self-organizing behaviors currently under study. Development of new imaging and image analysis technology in the lab, combined with the genetic resources in the Arabidopsis system, is providing exciting opportunity for studying cytoskeletal organization in the entire cell and quantitatively relating microtubule array pattern to anisotropic cell growth.