BioProject

The maize spikelet contains two florets, each of which contains three anthers. More...

The maize spikelet contains two florets, each of which contains three anthers. Morphologically, the anthers in the upper and lower florets proceed through the same developmental program. To test for global differences in gene expression between these anthers and to identify genes that are coordinately regulated during development, RNA isolated from upper and lower floret anthers at six developmental stages was used to hybridize cDNA microarrays. Approximately 9% of the tested genes exhibited statistically significant differences in gene expression between anthers in the upper and lower florets. This suggests that several basic biological processes are differentially regulated between upper and lower floret anthers, including photosynthesis, translation, and metabolism. To identify genes that are coordinately regulated during anther development, cluster analyses were performed. A variety of patterns of gene expression were observed. Five genes involved in programmed cell death were up-regulated at the time the tapetum begins to degenerate (i.e., the early microspore stage). This finding strongly supports the hypothesis that tapetal degeneration occurs via programmed cell death. In addition, many genes involved in protein synthesis exhibited differential expression patterns during anther development. Each microarray slide was scanned multiple times. This approach led to the identification an additional 30 to 40% of statistically significant differences in gene expression as compared to a single-scan strategy. Keywords: time course Overall design: Experimental aims: 1) To develop a cDNA microarray scanning approach that utilizes multiple scans of different intensities, thus maximizing the power to detecting statistically significant differences in gene expression; 2) To apply the multiple scan approach to identify differentially expressed genes in: a) the upper floret of (N)Ky21 at the selected stages of anther development; b) the lower floret of (N)Ky21 at the selected stages of anther development; and c) the upper vs. lower floret at each selected stage of anther development. Less...