B. anthracis transcriptome analysis using Illumina and SOLiD sequencing

Although gene expression has been studied in bacteria for decades, many aspects of the bacterial transcriptome remain poorly understood. Transcript structure, operon linkages, and absolute abundance information all provide valuable insights into gene function and regulation, but none has ever been determined on a genome-wide scale for any bacterium. Here we report the first comprehensive and unbiased definition of a bacterial transcriptome under various growth conditions. Using a high throughput sequencing approach, we mapped transcript start sites and operons throughout the genome, and enhanced existing genome annotations. Further, our data provide estimates of absolute transcript abundance, and suggest there is significant transcriptional heterogeneity within a clonal, synchronized bacterial population. Overall, our results offer an unprecedented view of gene expression and regulation in a bacterial cell. Overall design: Includes: Comparison of transcriptomes under 2 different atmospheric conditions using Illumina sequencing (2 Samples) and Comparison of transcriptomes in different growth phases under 2 different atmospheric conditions using SOLiD sequencing (6 Samples).