Department of Biology

Program

Molecular, Cellular & Developmental Biology

Research Areas

• Eukaryotic Cell Biology, Cytoskeleton and Signaling
• Plant Molecular Biology

Education

MPhil. Cambridge University, 1991

Ph.D., University of North Carolina, Chapel Hill, 1996

Postdoctoral and Research Fellow, Stanford University, 2005

Research Description

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.

Select Publications

Rania Rizk, Kevin Bohannon, Laura Wetzel, James Powers, Sidney Shaw, and Claire Walczak. 2009 MCAK and Paclitaxel Have Differential Effects on Spindle Microtubule Organization and Dynamics. Molecular Biology of the Cell (in Press).

Jessica Lucas and Sidney L. Shaw. 2008 Microtubule organization in the Arabidopsis seedling. Current Opinion in Plant Biology 11(1):94-98.

Sidney L. Shaw and Claire Walczak (2007) News and Views: Spindles One Speckle at a Time. Nature Cell Biology 9:1223-1224.

E. D. Salmon, Sidney L. Shaw, Jennifer Waters, Clare M. Waterman-Storer, Paul Maddox, Elaine Yeh, and Kerry Bloom. 2007. A high-resolution multimode digital microscope system. Methods in Cell Biology 81:187-218. Academic Press, New York.

Sidney L. Shaw. 2006. Imaging and the live plant cell. Plant Journal 45:573-598.

David Ehrhardt and Sidney L. Shaw. 2006. Microtubule Dynamics and Organization in the Plant Cortical array. Annual Reviews in Plant Molecular Biology 57:859-875.

Jacques Dumais, Sidney L. Shaw, Charles R. Steele, Sharon R. Long and Peter M. Ray. 2006 An anisotropic-viscoplastic model of plant cell morphogenesis by tip growth. International Journal of Developmental Biology 50: 209-222.

Jacques Dumais, Sharon R. Long, Sidney L. Shaw. 2004. The mechanics of surface expansion anisotropy in Medicago truncatula root hairs. Plant Physiology 136(2):3266-3275.

Raka Mitra, Sidney L. Shaw, Sharon Long. 2004. Six non-nodulating plant mutants defective for Nod factor-induced transcriptional changes associated with the legume-rhizobia symbiosis. PNAS 101(27):10217-10222.

Sidney L. Shaw, Roheena Kamyar and David W. Ehrhardt. 2003. Sustained microtubule treadmilling in Arabidopsis cortical arrays. Science 300(5626):1715-1718.