title: Structure and complexity of a bacterial transcriptome.
abstract: Although gene expression has been studied in bacteria for decades, many aspects of the bacterial transcriptome remain poorly understood. Transcript structure, operon linkages, and information on absolute abundance all provide valuable insights into gene function and regulation, but none has ever been determined on a genome-wide scale for any bacterium. Indeed, these aspects of the prokaryotic transcriptome have been explored on a large scale in only a few instances, and consequently little is known about the absolute composition of the mRNA population within a bacterial cell. Here we report the use of a high-throughput sequencing-based approach in assembling the first comprehensive, single-nucleotide resolution view of a bacterial transcriptome. We sampled the Bacillus anthracis transcriptome under a variety of growth conditions and showed that the data provide an accurate and high-resolution map of transcript start sites and operon structure throughout the genome. Further, the sequence data identified previously nonannotated regions with significant transcriptional activity and enhanced the accuracy of existing genome annotations. Finally, our data provide estimates of absolute transcript abundance and suggest that 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.
authors.affiliation: School of Biology, Georgia Institute of Technology, 310 Ferst Dr., Atlanta, GA 30332-0230, USA.
authors.forename: Karla D
authors.initials: KD
authors.lastname: Passalacqua
authors.forename: Anjana
authors.initials: A
authors.lastname: Varadarajan
authors.forename: Brian D
authors.initials: BD
authors.lastname: Ondov
authors.forename: David T
authors.initials: DT
authors.lastname: Okou
authors.forename: Michael E
authors.initials: ME
authors.lastname: Zwick
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Bergman
mesh_terms: D001408:Bacillus anthracis / Q000235:genetics*; D019295:Computational Biology; D020869:Gene Expression Profiling / Q000379:methods; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D012333:RNA, Messenger