Quantitative RNA expression analysis with Affymetrix Tiling 1.0R arrays identifies new E2F target genes

Area of Science:

• Plant Molecular Biology
• Genomics
• Transcriptome Analysis

Background:

• The Affymetrix ATH1 array is a standard for transcriptome analysis but lacks full coverage of Arabidopsis thaliana genes.
• Affymetrix's Arabidopsis Tiling 1.0R array provides whole-genome coverage for the Col-0 strain.

Purpose of the Study:

• To develop and validate an approach for quantitative mRNA expression analysis using the Arabidopsis Tiling 1.0R array.
• To compare the performance of tiling arrays with ATH1 arrays for transcriptome analysis.
• To identify novel genes regulated by the E2Fa-DPa transcription factor.

Main Methods:

• Developed a method to select unique tiling probes for genes and transcripts using TAIR7 annotation.
• Generated Chip Definition Files for the Tiling 1.0R array.
• Compared transcriptome data from wild-type and E2Fa-DPa overproducing transgenic Arabidopsis plants.

Main Results:

• Quantitative mRNA expression analysis using tiling arrays is comparable to ATH1 arrays after appropriate data pre-processing.
• Identified 368 new E2F-regulated genes using the tiling arrays.
• Discovered that a significant fraction of these new genes contain an E2F motif in their promoter, increasing direct E2F target candidates by nearly twofold.

Conclusions:

• The Arabidopsis Tiling 1.0R array is a powerful tool for comprehensive transcriptome analysis.
• This study significantly expands the known targets of the E2Fa-DPa transcription factor.
• The findings provide a more complete understanding of E2F-mediated gene regulation in Arabidopsis.