Comparative genome analysis of Salmonella Enteritidis PT4 and Salmonella Gallinarum 287/91 provides insights into evolutionary and host adaptation pathways
- Nicholas R. Thomson1,9,
- Debra J. Clayton2,
- Daniel Windhorst3,
- George Vernikos1,
- Susanne Davidson2,
- Carol Churcher1,
- Michael A. Quail1,
- Mark Stevens2,
- Michael A. Jones4,
- Michael Watson2,
- Andy Barron1,
- Abigail Layton2,
- Derek Pickard1,
- Robert A. Kingsley1,
- Alex Bignell1,
- Louise Clark1,
- Barbara Harris1,
- Doug Ormond1,
- Zahra Abdellah1,
- Karen Brooks1,
- Inna Cherevach1,
- Tracey Chillingworth1,
- John Woodward1,
- Halina Norberczak1,
- Angela Lord1,
- Claire Arrowsmith1,
- Kay Jagels1,
- Sharon Moule1,
- Karen Mungall1,
- Mandy Saunders1,
- Sally Whitehead1,
- Jose A. Chabalgoity5,
- Duncan Maskell6,
- Tom Humphreys7,
- Mark Roberts8,
- Paul A. Barrow4,
- Gordon Dougan1, and
- Julian Parkhill1
Abstract
We have determined the complete genome sequences of a host-promiscuous Salmonella enterica serovar Enteritidis PT4 isolate P125109 and a chicken restricted Salmonella enterica serovar Gallinarum isolate 287/91. Genome comparisons between these and other Salmonella isolates, indicates that S. Gallinarum 287/91 is a recently evolved descendent of S. Enteritidis. Significantly the genome of S. Gallinarum, has undergone extensive degradation through deletion and pseudogene formation. Comparison of the pseudogenes in S. Gallinarum with those identified previously in other host adapted bacteria reveals the loss of many common functional traits and provides insights into possible mechanisms of host and tissue adaptation. We propose that experimental analysis in chickens and mice of S. Enteritidis harbouring mutations in functional homologues of the pseudogenes present in S. Gallinarum could provide an experimentally tractable route towards unravelling the genetic basis of host adaption in S. enterica.
Footnotes
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- Received February 12, 2008.
- Accepted June 17, 2008.
- Copyright © 2008, Cold Spring Harbor Laboratory Press
