Whole-Genome
Comparison between Photorhabdus Strains To Identify
Genomic Regions Involved in the Specificity of Nematode Interaction
S. Gaudriault,1* E. Duchaud,1†
A. Lanois,1 A.-S. Canoy,2‡ S.
Bourot,2 R. DeRose,2§
F. Kunst,3 N. Boemare,1 and A. Givaudan1
Laboratoire EMIP Ecologie Microbienne des Insectes et Interaction
Hotes-Pathogene, Universite
Montpellier II, UMR1133 INRA-UMII, 34095 Montpellier Cedex
5, France.
Abstract
The bacterium Photorhabdus establishes
a highly specific association with Heterorhabditis,
its nematode host. Photorhabdus strains associated
with Heterorhabditis bacteriophora or Heterorhabditis
megidis were compared using a Photorhabdus DNA
microarray. We describe 31 regions belonging to the Photorhabdus
flexible gene pool. Distribution analysis of regions among
the Photorhabdus genus identified loci possibly involved
in nematode specificity.Photorhabdus is an entomopathogenic
gram-negative bacterium belonging to the Enterobacteriaceae.
Both Photorhabdus luminescens and Photorhabdus
temperata species are symbionts of entomopathogenic
Heterorhabditis nematodes (7). Bacterial and nematode
taxonomic data reveal a highly specific association between
bacterial strains and nematode species. A recently described
species, Photorhabdus asymbiotica, was never found
to be associated with nematodes but was isolated from human
infections (3, 12, 15, 22). Although a few studies have identified
several Photorhabdus genes that are required for
normal growth and development of the nematode (5, 6, 9, 19,
29), we have little molecular and functional data about the
first step of nematode colonization and nematode specificity.
Keywords:Photorhabdus;Heterorhabditis;Heterorhabditisbacteriophora;Heterorhabditismegidis;PhotorhabdusDNA
microarray;Photorhabdus genus;Enterobacteriaceae;taxonomy.
Corresponding author: Tel 33 4 67144812;
Fax 33 4 67144679
E-mail: sgaudriault@univ-montp2.fr |
