Microarrays provide the means for the large-scale analysis of gene expression patterns in living organisms. My laboratory is part of three federally funded projects that are directed toward an understanding of the regulation of gene expression in higher plants.

In the first project, funded by the United States Department of Agriculture (USDA) and the Human Frontier Science Program, we are examining the functions and expression patterns of the approximately 340 members of the cytochrome P450 gene superfamily in Arabidopsis thaliana. The second project, funded by the NSF program in Plant Genomics, involves analysis of the changes in gene expression that accompany imposition of drought and salinity stress on plants. The final project, also funded by the NSF Plant Genome program, proposes to categorize at least 50,000 ESTs and cDNAs from maize (Zea mays) and provide this information to the public sector. In all of these projects, microarrays have an integral role. In the first case, we are studying tissue- and stimulus-specific gene expression to define the catalytic activities of the different P450s. In the second case, we are employing microarrays to unravel hierarchical patterns of gene regulation in response to imposed stress. For the final project, we are responsible for providing microarrays of the sequenced ESTs as a service to the maize scientific community.

We are working to solve a variety of problems at all levels, including identification of suitable substrates for printing, debugging programs for commercial arrayers, establishing sensitivity and reproducibility criteria, implementing high-throughput methods including sample tracking and methods for data analysis, reduction and archiving.

Finally, my laboratory provides campus-wide microarraying and scanning services for the University of Arizona, and we are an integral part of the core program in cancer biology currently underway at the Arizona Cancer Center.