Project description:Proteus mirabilis is a leading cause of catheter-associated urinary tract infections (UTIs) and urolithiasis. The transcriptional regulator MrpJ inversely modulates two critical aspects of P. mirabilis UTI progression: fimbria-mediated attachment to the urinary tract, and flagella-mediated motility. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) was used for the first time in a CAUTI pathogen to probe for in vivo direct targets of MrpJ. ChIP-seq revealed 81 78 direct MrpJ targets, including genes for motility, fimbriae and a type VI secretion system (T6SS), and the putative MrpJ binding sequence ACnCnnnnnnnGnGT.
Project description:Swarming motility by the urinary tract pathogen Proteus mirabilis has been a long-studied, but little understood phenomenon. On agar, a P. mirabilis colony grows outward in a bullseye pattern formed by consecutive waves of rapid swarming followed by consolidation into shorter cells. To examine differential gene expression in these growth phases, a microarray, constructed based on the completed genome sequence and annotation, was undertaken. RNA from 1) broth-cultured, or 2) swarming cells was extracted to assess transcription during each of these growth states.
Project description:Swarming motility by the urinary tract pathogen Proteus mirabilis has been a long-studied, but little understood phenomenon. On agar, a P. mirabilis colony grows outward in a bullseye pattern formed by consecutive waves of rapid swarming followed by consolidation into shorter cells. To examine differential gene expression in these growth phases, a microarray, constructed based on the completed genome sequence and annotation, was undertaken. RNA from 1) broth-cultured, or 2) consolidation-phase cells was extracted to assess transcription during each of these growth states.
Project description:Oomycetes from the genus Phytophthora are fungus-like plant pathogens that are devastating for agriculture and natural ecosystems. Due to particular physiological characteristics, no treatments against diseases caused by oomycetes are presently available. To develop such treatments, it appears essential to dissect the molecular mechanisms that determine the interaction between Phytophthora species and host plants. The present project is focused on the molecular mechanisms that underlie the compatible plant-oomycete interaction and plant disease. The laboratory developed a novel interaction system involving the model plant, Arabidopsis thaliana, and Phytophthora parasitica, a soil-borne pathogen infecting a wide host range, thus representing the majority of Phytophthora species. A characteristic feature of the compatible Arabidopsis/P. parasitica interaction is an extended biotrophic phase, before infection becomes necrotrophic. Because the initial biotrophic phase is extremely short on natural (e.g. solanaceous) hosts, the Arabidopsis system provides the opportunity to analyze, for both interaction partners, the molecular events that determine the initiation of infection and the switch to necrotrophy. The present project aims at analyzing the compatible interaction between A. thaliana roots and P. parasitica. The Affymetrix A. thaliana full genome chip will be used to characterize modulations of the transcriptome occurring over a period of 24h from the onset of plant root infection to the beginning of necrotrophy. Parallel to this study, a custom-designed P. parasitica biochip will enable analyzing of P. parasitica gene expression during the same stages.
Project description:Oomycetes from the genus Phytophthora are fungus-like plant pathogens that are devastating for agriculture and natural ecosystems. Due to particular physiological characteristics, no treatments against diseases caused by oomycetes are presently available. To develop such treatments, it appears essential to dissect the molecular mechanisms that determine the interaction between Phytophthora species and host plants. The present project is focused on the molecular mechanisms that underlie the compatible plant-oomycete interaction and plant disease.The laboratory developed a novel interaction system involving the model plant, Arabidopsis thaliana and Phytophthora parasitica, a soil-borne pathogen infecting a wide host range, thus representing the majority of Phytophthora species. A characteristic feature of the compatible Arabidopsis/Phytophthora parasitica interaction is an extended biotrophic phase, before infection becomes necrotrophic. Because the initial biotrophic phase is extremely short on natural (e.g. solanaceous) hosts, the Arabidopsis system provides the opportunity to analyze, for both interaction partners, the molecular events that determine the initiation of infection and the switch to necrotrophy.The present project aims at analyzing the compatible interaction between A. thaliana roots and Phytophthora parasitica. The Affymetrix A. thaliana full genome chip will be used to characterize modulations of the transcriptome occurring over a period of 24h from the onset of plant root infection to the beginning of necrotrophy. Parallel to this study, a custom designed Phytophthora parasitica biochip will enable analyzing of Phytophthora parasitica gene expression during the same stages. The pathosystem involving A. thaliana and Phytophthora parasitica was described in Attard A, Gourgues M, Callemeyn-Torre N, Keller H. 2010. The New phytologist 187: 449–460. The protocol for recovery of RNA from purified appressoria was described in Kebdani N, Pieuchot L, Deleury E, Panabieres F, Le Berre JY, Gourgues M. 2010. New Phytol 185: 248–257.
Project description:Deep sequencing of small RNAs from three Phytophthora species, P. infestans, P. ramorum and P. sojae, was done to systematically analyze small RNA-generating components of Phytophthora genomes. We found that each species produces two distinct small RNA populations that are predominantly 21- or 25-nucleotides long. We present evidence that 25-nucleotide small RNAs are short-interfering RNAs that silence repetitive genetic elements. In contrast, 21-nucleotide small RNAs are associated with inverted repeats, including a novel microRNA family, and may function at the post-transcriptional level. Phytophthora infestans mycelium small RNAs were sequenced and aligned to the P. infestans genome for analysis.
Project description:Oomycetes from the genus Phytophthora are fungus-like plant pathogens that are devastating for agriculture and natural ecosystems. Due to particular physiological characteristics, no treatments against diseases caused by oomycetes are presently available. To develop such treatments, it appears essential to dissect the molecular mechanisms that determine the interaction between Phytophthora species and host plants. The present project is focused on the molecular mechanisms that underlie the compatible plant-oomycete interaction and plant disease. The laboratory developed a novel interaction system involving the model plant, Arabidopsis thaliana, and Phytophthora parasitica, a soil-borne pathogen infecting a wide host range, thus representing the majority of Phytophthora species. A characteristic feature of the compatible Arabidopsis/P. parasitica interaction is an extended biotrophic phase, before infection becomes necrotrophic. Because the initial biotrophic phase is extremely short on natural (e.g. solanaceous) hosts, the Arabidopsis system provides the opportunity to analyze, for both interaction partners, the molecular events that determine the initiation of infection and the switch to necrotrophy. The present project aims at analyzing the compatible interaction between A. thaliana roots and P. parasitica. The Affymetrix A. thaliana full genome chip will be used to characterize modulations of the transcriptome occurring over a period of 24h from the onset of plant root infection to the beginning of necrotrophy. Parallel to this study, a custom-designed P. parasitica biochip will enable analyzing of P. parasitica gene expression during the same stages. 10 samples were used in this experiment.
Project description:Deep sequencing of small RNAs from three Phytophthora species, P. infestans, P. ramorum and P. sojae, was done to systematically analyze small RNA-generating components of Phytophthora genomes. We found that each species produces two distinct small RNA populations that are predominantly 21- or 25-nucleotides long. We present evidence that 25-nucleotide small RNAs are short-interfering RNAs that silence repetitive genetic elements. In contrast, 21-nucleotide small RNAs are associated with inverted repeats, including a novel microRNA family, and may function at the post-transcriptional level. Phytophthora sojae mycelium small RNAs were sequenced and aligned to the P. sojae genome for analysis. *Raw data files (fastq) are unavailable for this study.