Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it>
<p>Abstract</p> <p>Background</p> <p><it>Photorhabdus </it>and <it>Xenorhabdus </it>are Gram-negative, phylogenetically related, enterobacteria, forming mutualism with the entomopathogenic nematodes <it>Heterorhabditis </it>and <it...
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| Format: | Article |
| Language: | English |
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BMC
2009-09-01
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| Series: | BMC Genomics |
| Online Access: | http://www.biomedcentral.com/1471-2164/10/433 |
| _version_ | 1828774460959752192 |
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| author | Sreevatsan Srinand An Ruisheng Grewal Parwinder S |
| author_facet | Sreevatsan Srinand An Ruisheng Grewal Parwinder S |
| author_sort | Sreevatsan Srinand |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p><it>Photorhabdus </it>and <it>Xenorhabdus </it>are Gram-negative, phylogenetically related, enterobacteria, forming mutualism with the entomopathogenic nematodes <it>Heterorhabditis </it>and <it>Steinernema</it>, respectively. The mutualistic bacteria living in the intestines of the nematode infective juveniles are pathogenic to the insect upon release by the nematodes into the insect hemolymph. Such a switch needs activation of genes that promote bacterial virulence. We studied <it>in vivo </it>gene expression in <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the white grub <it>Rhizotrogus majalis </it>using selective capture of transcribed sequences technique.</p> <p>Results</p> <p>A total of 40 genes in <it>P. temperata </it>and 39 in <it>X. koppenhoeferi </it>were found to be upregulated in <it>R. majalis </it>hemolymph at 24 h post infection. Genomic presence or upregulation of these genes specific in either one of the bacterium was confirmed by the assay of comparative hybridization, and the changes of randomly selected genes were further validated by quantitative real-time PCR. The identified genes could be broadly divided into seven functional groups including cell surface structure, regulation, virulence and secretion, stress response, intracellular metabolism, nutrient scavenging, and unknown. The two bacteria shared more genes in stress response category than any other functional group. More than 60% of the identified genes were uniquely induced in either bacterium suggesting vastly different molecular mechanisms of pathogenicity to the same insect host. In <it>P. temperata lysR </it>gene encoding transcriptional activator was induced, while genes <it>yijC </it>and <it>rseA </it>encoding transcriptional repressors were induced in <it>X. koppenhoeferi</it>. Lipopolysaccharide synthesis gene <it>lpsE </it>was induced in <it>X. koppenhoeferi </it>but not in <it>P. temperata</it>. Except <it>tcaC </it>and <it>hemolysin </it>related genes, other virulence genes were different between the two bacteria. Genes involved in TCA cycle were induced in <it>P. temperata </it>whereas those involved in glyoxylate pathway were induced in <it>X. koppenhoeferi</it>, suggesting differences in metabolism between the two bacteria in the same insect host. Upregulation of genes encoding different types of nutrient uptake systems further emphasized the differences in nutritional requirements of the two bacteria in the same insect host. <it>Photorhabdus temperata </it>displayed upregulation of genes encoding siderophore-dependent iron uptake system, but <it>X. koppenhoeferi </it>upregulated genes encoding siderophore-independent ion uptake system. <it>Photorhabdus temperata </it>induced genes for amino acid acquisition but <it>X. koppenhoeferi </it>upregulated <it>malF </it>gene, encoding a maltose uptake system. Further analyses identified possible mechanistic associations between the identified gene products in metabolic pathways, providing an interactive model of pathogenesis for each bacterium species.</p> <p>Conclusion</p> <p>This study identifies set of genes induced in <it>P. temperata </it>and <it>X. koppenhoeferi </it>upon infection of <it>R. majalis</it>, and highlights differences in molecular features used by these two closely related bacteria to promote their pathogenicity in the same insect host.</p> |
| first_indexed | 2024-12-11T15:21:44Z |
| format | Article |
| id | doaj.art-6f44269e619f44b2a33786a4485e9463 |
| institution | Directory Open Access Journal |
| issn | 1471-2164 |
| language | English |
| last_indexed | 2024-12-11T15:21:44Z |
| publishDate | 2009-09-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Genomics |
| spelling | doaj.art-6f44269e619f44b2a33786a4485e94632022-12-22T01:00:21ZengBMCBMC Genomics1471-21642009-09-0110143310.1186/1471-2164-10-433Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it>Sreevatsan SrinandAn RuishengGrewal Parwinder S<p>Abstract</p> <p>Background</p> <p><it>Photorhabdus </it>and <it>Xenorhabdus </it>are Gram-negative, phylogenetically related, enterobacteria, forming mutualism with the entomopathogenic nematodes <it>Heterorhabditis </it>and <it>Steinernema</it>, respectively. The mutualistic bacteria living in the intestines of the nematode infective juveniles are pathogenic to the insect upon release by the nematodes into the insect hemolymph. Such a switch needs activation of genes that promote bacterial virulence. We studied <it>in vivo </it>gene expression in <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the white grub <it>Rhizotrogus majalis </it>using selective capture of transcribed sequences technique.</p> <p>Results</p> <p>A total of 40 genes in <it>P. temperata </it>and 39 in <it>X. koppenhoeferi </it>were found to be upregulated in <it>R. majalis </it>hemolymph at 24 h post infection. Genomic presence or upregulation of these genes specific in either one of the bacterium was confirmed by the assay of comparative hybridization, and the changes of randomly selected genes were further validated by quantitative real-time PCR. The identified genes could be broadly divided into seven functional groups including cell surface structure, regulation, virulence and secretion, stress response, intracellular metabolism, nutrient scavenging, and unknown. The two bacteria shared more genes in stress response category than any other functional group. More than 60% of the identified genes were uniquely induced in either bacterium suggesting vastly different molecular mechanisms of pathogenicity to the same insect host. In <it>P. temperata lysR </it>gene encoding transcriptional activator was induced, while genes <it>yijC </it>and <it>rseA </it>encoding transcriptional repressors were induced in <it>X. koppenhoeferi</it>. Lipopolysaccharide synthesis gene <it>lpsE </it>was induced in <it>X. koppenhoeferi </it>but not in <it>P. temperata</it>. Except <it>tcaC </it>and <it>hemolysin </it>related genes, other virulence genes were different between the two bacteria. Genes involved in TCA cycle were induced in <it>P. temperata </it>whereas those involved in glyoxylate pathway were induced in <it>X. koppenhoeferi</it>, suggesting differences in metabolism between the two bacteria in the same insect host. Upregulation of genes encoding different types of nutrient uptake systems further emphasized the differences in nutritional requirements of the two bacteria in the same insect host. <it>Photorhabdus temperata </it>displayed upregulation of genes encoding siderophore-dependent iron uptake system, but <it>X. koppenhoeferi </it>upregulated genes encoding siderophore-independent ion uptake system. <it>Photorhabdus temperata </it>induced genes for amino acid acquisition but <it>X. koppenhoeferi </it>upregulated <it>malF </it>gene, encoding a maltose uptake system. Further analyses identified possible mechanistic associations between the identified gene products in metabolic pathways, providing an interactive model of pathogenesis for each bacterium species.</p> <p>Conclusion</p> <p>This study identifies set of genes induced in <it>P. temperata </it>and <it>X. koppenhoeferi </it>upon infection of <it>R. majalis</it>, and highlights differences in molecular features used by these two closely related bacteria to promote their pathogenicity in the same insect host.</p>http://www.biomedcentral.com/1471-2164/10/433 |
| spellingShingle | Sreevatsan Srinand An Ruisheng Grewal Parwinder S Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it> BMC Genomics |
| title | Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it> |
| title_full | Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it> |
| title_fullStr | Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it> |
| title_full_unstemmed | Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it> |
| title_short | Comparative <it>in vivo </it>gene expression of the closely related bacteria <it>Photorhabdus temperata </it>and <it>Xenorhabdus koppenhoeferi </it>upon infection of the same insect host, <it>Rhizotrogus majalis</it> |
| title_sort | comparative it in vivo it gene expression of the closely related bacteria it photorhabdus temperata it and it xenorhabdus koppenhoeferi it upon infection of the same insect host it rhizotrogus majalis it |
| url | http://www.biomedcentral.com/1471-2164/10/433 |
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