The distribution of insertion sequences in the genome ofShigella flexneristrain 2457T

Autor: Lamia Zaghloul, Mark M. Tanaka, Hui Yee Chin, Ruiting Lan, Chaka Tang, Emily J. Bek
Přispěvatelé: Laboratoire Joliot Curie, École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS), School of Biotechnology and Biomolecular Sciences, University of New South Wales [Sydney] (UNSW)
Rok vydání: 2007
Předmět:
Zdroj: FEMS Microbiology Letters
FEMS Microbiology Letters, 2007, 277, pp.197-204. ⟨10.1111/j.1574-6968.2007.00957.x⟩
ISSN: 1574-6968
0378-1097
DOI: 10.1111/j.1574-6968.2007.00957.x
Popis: Shigella flexneri, which causes shigellosis in humans, evolved from Escherichia coli. The sequencing of Shigella genomes has revealed that a large number of insertion sequence (IS) elements (over 200 elements) reside in the genome. Although the presence of these elements has been noted previously and summarized, more detailed analyses are required to understand their evolutionary significance. Here, the genome of S. flexneri strain 2457T is used to investigate the spatial distribution of IS copies around the chromosome and the location of elements with respect to genes. It is found that most IS isoforms occur essentially randomly around the genome. Two exceptions are IS91 and IS911, which appear to cluster due to local hopping. The location of IS elements with respect to genes is biased, however, revealing the action of natural selection. The non-coding regions of the genome (no more than 21%) carry disproportionally more IS elements (at least 28%) than the coding regions, implying that selection acts against insertion into genes. Of the genes disrupted by ISs, those involved in signal transduction, intracellular trafficking, and cell motility are most commonly targeted, suggesting selection against genes in these categories.
Databáze: OpenAIRE
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