Comparative Transcriptome Analysis Of Yersinia Pestis In Response To Various Environmental Stresses

Plague has ravaged human populations for many centuries and claimed hundred millions of lives in history. Plague normally cycles between fleas and rodent hosts, with humans providing an unproductive alternative. Yersinia pestis is the etiologic agent of plague. Its growth and proliferation within the macrophage cell after early-stage entry into host is considered as a key step for further infection and pathogenesis. Since Y. pestis undergoes various types of environmental changes during transmission and infection, a wide range of rapid, adaptive responses to the changing niches are required. In response to these stresses, bacteria can activate or repress the transcription of a specific set of genes whose products play roles in coping with a given physico-chemical stress or whose transcription was inhibited by specific environmental and cellular signals.Y. pestis whole-genome DNA microarray was used to investigate global transcriptional responses when wild-type Y. pestis was grown in chemically defined medium with various in vitro environmental stresses, including high or low temperature, high salt or osmolarity, low concentration of hydrogen peroxide and low Mg²⁺. In addition several Y. pestis mutants of global regulator (OmpR, OxyR and PhoP) were exposed to specific stress to respectively examine the possible regulated genes.The microarray analysis demonstrated that Y. pestis has the ability to alter gene transcription extensively in response to the in vitro environmental stresses mentioned above. Our data provided different genome-wide profiles of gene transcription induced by different environmental changes, which give us a global impression of cellular metabolism and virulence under various conditions. Sometimes the transcription profile of certain environmental stresses could be used as a bio-probe for evaluating gene regulation in in vivo environments. Some possible regulated genes, by the global regulator OmpR, OxyR and PhoP, screened out by the transcriptome analysis of Y. pestis mutant need elucidating further.All data on transcriptional changes of all 4,005 genes anchoring on Y. pestis genome microarray was collected and the cluster analysis was performed based on gene classes. The...