A comparison of dense transposon insertion libraries in the Salmonella serovarsThypi and Typhimurium

Lars Barquist, Gemma C. Langridge, Daniel J. Turner, Minh-Duy Phan, A. Keith Turner, Alex Bateman, Julian Parkhill, John Wain, Paul P. Gardner

Research output: Contribution to journalArticlepeer-review

72 Citations (Scopus)

Abstract

Salmonella Typhi and Typhimurium diverged only ~50 000 years ago, yet have very different host ranges and pathogenicity. Despite the availability of multiple whole-genome sequences, the genetic differences that have driven these changes in phenotype are only beginning to be understood. In this study, we use transposon-directed insertion-site sequencing to probe differences in gene requirements for competitive growth in rich media between these two closely related serovars. We identify a conserved core of 281 genes that are required for growth in both serovars, 228 of which are essential in Escherichia coli. We are able to identify active prophage elements through the requirement for their repressors. We also find distinct differences in requirements for genes involved in cell surface structure biogenesis and iron utilization. Finally, we demonstrate that transposon-directed insertion-site sequencing is not only applicable to the protein-coding content of the cell but also has sufficient resolution to generate hypotheses regarding the functions of non-coding RNAs (ncRNAs) as well. We are able to assign probable functions to a number of cis-regulatory ncRNA elements, as well as to infer likely differences in trans-acting ncRNA regulatory networks.
Original languageEnglish
Pages (from-to)4549-4564
Number of pages15
JournalNucleic Acids Research
Volume41
Issue number8
DOIs
Publication statusPublished - Apr 2013

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