Plant & Animal Genomes XI Conference

January 11-15, 2003
Town & Country Convention Center
San Diego, CA

Poster: Microarrays
            

GENE EXPRESSION ANALYSIS OF COTTON PILOSE MUTANT WITH ALTERED FIBER CHARACTERISTICS

Department of Agronomy and Range Science, University of California Davis, CA 95616-8515 USA

Cotton fibers are single-celled, unbranched seed trichomes that grow rapidly through four developmental stages. Beside their economical importance, cotton fibers provide an excellent system to study the development of plant cell elongation. To elucidate the patterns of gene regulation and molecular mechanisms during fiber development we are applying cDNA microarray analysis to wild type and mutants with altered fiber kinetics. For this purpose, we have constructed microarrays comprising 4875 non-redundant cDNAs selected from the NSF Cotton Genome Project’s fiber dbEST. Pilose (H₂), a single nuclear dominant mutation, has altered fiber elongation kinetics and shorter mature fibers. The phenotypic differences become observable with the onset of fiber initiation. Probes prepared from fibers or ovules with fibers collected at 0, 10, and 24 days after anthesis (dpa) were used to construct the expression profiles. Parallel to expression profiling, wild type and mutant fiber cells were studied for their phenotype using scanning electron microscope. Preliminary results from the 10 dpa comparisons indicate that expression of a number of structural genes, including those encoding subunit A of the vacuolar H⁺-ATPase, and some unidentified genes is altered in the mutant fibers. These results with phenotypic observations suggest that the H₂ mutation occurs upstream in the genetic regulation of fiber development and that a subset of the genes exhibiting altered expression in this fiber mutant are likely downstream targets of potential regulatory elements. Comparative analysis of the time-course expression profiles of wild type and mutant fibers will be presented.