Mary E. Williams
Associate Professor of Biology

• F.W. Olin Science Center, Room 2351
• 1250 N. Dartmouth Ave.
  Claremont, CA 91711
• (909) 607-1218
• Mary_Williams@hmc.edu

Education & Professional Experience

• B.A., University of California, Berkeley
• Ph.D., The Rockefeller University
• Postdoctoral Fellow, University of California, Berkeley

Courses

• Bio 52: Introductory Biology
• Bio 54: Biology Laboratory - read more
• Bio 101: Structure & Function
• Bio 103: Comparative Physiology Laboratory
• Bio 111: Molecular Biology Laboratory - read more
• Bio 164: Cell Biology & Genetics
• Bio 166: Cell Biology & Genetics Laboratory
• Bio 167: Plant Development
• Bio 169: Plant Development Laboratory

Research Interests

Arabidopsis thaliana. See more Arabidopsis pictures! Tour Prof. Williams’ lab

Professor Williams’s research focuses on phosphoinositide signaling in the model plant Arabidopsis thaliana. Phosphoinositides are a family of lipid signals that facilitate membrane and cytoskeleton functions in cells. We have identified a mutant that is altered in its phosphoinositide levels and cellular activities. This mutant resembles a plant experiencing hyperosmotic stress, underlying the importance of phosphoinositides in plant stress responses. We are using gene expression profiling, confocal microscopy, and genetic, molecular biological and biochemical approaches to uncover the functions of phosphoinositides in plant cells. [more]

Teaching - Investigative Laboratories

Bio 54: Introductory Biology Laboratory
Students in Introductory Biology Lab carry out four four-week lab exercises encompassing experimental ecology, enzyme kinetics, molecular biology and genetic analysis. In the genetic analysis module, students examine three different mutants in Arabidopsis thaliana with abnormal flower development. Based on the observed phenotypes of the single mutants, students predict double mutant phenotypes. Students then examine F2 populations resulting from a dihybrid cross to try to identify a double mutant plant. Students examine the proportions of each phenotype in the F2 population to both support their claim that a double mutant has been found, and consider whether the two genes being investigated are physically linked on the same chromosome. Additional information on this lab module is available upon request.

Bio 111: Molecular Biology Laboratory
In this lab, students use a diverse set of molecular biological methods to complete one or two multi-week research project. Students solve a problem set forth by a faculty member such as cloning a gene, characterizing a gene’s expression pattern or creating a recombinant plasmid. Students learn to use computational methods such as restriction mapping, primer design and image analysis tools, and genomic, mutant and microarray databases as essential components of their projects. Students design and carry out experiments independently but with faculty guidance, helping them develop research skills. One of the most engaging aspects of this course is that the outcomes of the project are unknown. Projects have included “Characterization of genes encoding guard-cell specific proteins in Arabidopsis thaliana” and “Characterization of EB1 proteins in Tetrahymena thermophila”. Additional information on this course and these projects is available upon request.

Selected Publications

M. E. Williams, J. Torabinejad, E. Cohick*, K. Parker*, E. J. Drake, J. E. Thompson, M. Hortter*, and D. B. DeWald. 2005. Mutations in the Arabidopsis phosphoinositide phosphatase gene SAC9 lead to overaccumulation of PtdIns(4,5)P2 and constitutive expression of the stress-response pathway. Plant Physiol. 138: 686-700. [article]

Hoeling, B. M., A. D. Fernandez*, R. C. Haskell, E. Huang*, W. R. Myers*, D. C. Petersen, S. E. Ungersma*, R. Wang, M. E. Williams, and S. E. Fraser. 2000. An optical coherence microscope for 3-dimensional imaging in developmental biology. Optics Express 67: 136-146. [article]

Hettinger, J. W., M. Mattozzi*, W. R. Myers*, M. E. Williams, A. Reeves, R. L. Parsons, R. C. Haskell, D. C. Petersen, R. Wang, and J. I. Medford. 2000. Optical coherence microscopy: a technology for rapid, in vivo, non-destructive visualization of plants and plant cells. Plant Physiology 123: 3-16. [article]

Purves, W. K., and M. E. Williams. 1998. Computers and learning. Artificial Intelligence for Engineering Design, Analysis, and Manufacturing (AIEDAM) 12: 47-48. [abstract]

Williams, M. E., and I. M. Sussex. 1995. Developmental regulation of ribosomal protein L16 genes in Arabidopsis thaliana. Plant Journal 8: 65-76. [abstract]

Laskowski, M. J., M. E. Williams, H. C. Nusbaum, and I. M. Sussex. 1995. Formation of lateral root meristems is a two-stage process. Development 121: 3303-3310. [article (pdf)]

Sussex, I. M., J. A. Godoy, N. M. Kerk, M. J. Laskowski, H. C. Nusbaum, J. A. Welsch, and M. E. Williams. 1995. Cellular and molecular events in a newly organizing lateral root meristem. Phil. Trans. R. Soc. Lond. B 350: 39-42. [abstract]

Sussex, I. M., J. A. Godoy, N. M. Kerk, M. J. Laskowski, H. C. Nusbaum, J. A. Welsch, and M. E. Williams. 1994. Molecular and cellular events in the formation of new meristems. pp. 31-35. In M. Terzi, R. Cella, and A. Falavigna, eds. Current Issues in Plant Molecular and Cellular Biology. Kluwer Academic Publishers, Dordrecht.

Williams, M. E., R. Foster, and N.-H. Chua. 1992. Sequences flanking the hexameric G-box CACGTG affect the specificity of protein binding. Plant Cell 4: 485-496.

Williams, M. E., J. Mundy, S. A. Kay, and N.-H. Chua. 1990. Differential expression of two related organ-specific genes in pea. Plant Mol. Biol. 14: 756-774.

Barlowe, C. K., M. E. Williams, J. C. Rabinowitz, and D. R. Appling. 1989. Site-directed mutagenesis of yeast C1-tetrahydrofolate synthase: analysis of an overlapping active site in a multifunctional enzyme. Biochemistry 28: 2099-2106.

Outreach Interests

Professor Williams is Chair of the Education Committee of the American Society of Plant Biologists. The mission of the ASPB Education Committee is to promote and improve the teaching and public awareness of plant biology as a constantly expanding science (www.aspb.org/education/). Through this position, Professor Williams has developed and disseminated resources for teachers who want to incorporate plant biology into their classrooms, as well as resources for teaching plant biology at the undergraduate level.