Poster: Genomics Resources

Abs # 942: Expression pattern screening for agriculture genomics

Presenter:	Kris, Richard M, richardkris@earthlink.net
Authors	Kris, Richard M (A)   Felder, Stephen  (A)   Deyholos, Mike  (C)   Botros, Ihab  (B)   Martel, Ralph  (B)   Seligmann, Bruce  (B)   Lambert, Georgina  (D)   Galbraith, David  (D)
Affiliations:	(A): NeoGen, LLC., PO Box 64326, Tucson, Arizona 85728 (B): High Throughput Genomics, Inc., 6296 E. Grant Road,Tucson, Arizona 85712 (C): University of Alberta, Edmonton, AB Canada T6G 2E9 (D): University of Arizona, Department of Plant Sciences,Tucson, Arizona 85721

We have utilized a quantitative high-throughput gene chip assay for discovery of chemicals that induce changed patterns of gene expression in individual Arabidopsis seedlings. This assay involves growing individual plants within each well of a 96 well microplate. Each plant is treated with a test compound, and the entire plate is then processed to produce homogenates within each well. The released RNA is then employed for a nuclease protection reaction, which is coupled to a mini gene chip, termed ArrayPlate^TM, printed in a 96-well format for readout. The ArrayPlate^TM allows simultaneous testing of the expression of a pre-selected specific group of genes of interest and appropriate controls. Features of the assay include: (1) No RNA purification is needed. This arrangement allows DNA array technology to be used in high throughput, with increased reliability and decreased cost. (2) The method is extremely sensitive and accurate. Genes can be measured that are expressing transcripts at very low levels – 12 ng of RNA represents the lower limit of detection. (3) The method is facile and flexible. The 96-well format means that RNA can be released from 96 separate tissue or plant samples for each plate that is employed. Further the ArrayPlate^TM can be designed to measure any combination of gene transcripts. This means the platform can be used for facile and efficient testing of gene targets including newly identified genes, and also to provide important information about selectivity and specificity of gene expression. In addition, gene expression profiling can be done from parts of plants that are grown outside 96 well plates. We illustrate features of the assay including measurement of gene expression within single Arabidopsis leaves and siliques.