title: Changes in activity of metabolic and regulatory pathways during germination of S. coelicolor.
abstract: BACKGROUND
  Bacterial spore germination is a developmental process during which all required metabolic pathways are restored to transfer cells from their dormant state into vegetative growth. Streptomyces are soil dwelling filamentous bacteria with complex life cycle, studied mostly for they ability to synthesize secondary metabolites including antibiotics.
  
  
  RESULTS
  Here, we present a systematic approach that analyzes gene expression data obtained from 13 time points taken over 5.5 h of Streptomyces germination. Genes whose expression was significantly enhanced/diminished during the time-course were identified, and classified to metabolic and regulatory pathways. The classification into metabolic pathways revealed timing of the activation of specific pathways during the course of germination. The analysis also identified remarkable changes in the expression of specific sigma factors over the course of germination. Based on our knowledge of the targets of these factors, we speculate on their possible roles during germination. Among the factors whose expression was enhanced during the initial part of germination, SigE is though to manage cell wall reconstruction, SigR controls protein re-aggregation, and others (SigH, SigB, SigI, SigJ) control osmotic and oxidative stress responses.
  
  
  CONCLUSIONS
  From the results, we conclude that most of the metabolic pathway mRNAs required for the initial phases of germination were synthesized during the sporulation process and stably conserved in the spore. After rehydration in growth medium, the stored mRNAs are being degraded and resynthesized during first hour. From the analysis of sigma factors we conclude that conditions favoring germination evoke stress-like cell responses.
authors.forename: Jan
authors.initials: J
authors.lastname: Bobek
authors.forename: Eva
authors.initials: E
authors.lastname: Strakova
authors.forename: Alice
authors.initials: A
authors.lastname: Zikova
authors.affiliation: Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Bioinformatics, Vídeňská 1083, 142 20 Prague 4, Czech Republic. vohr@biomed.cas.cz.
authors.forename: Jiri
authors.initials: J
authors.lastname: Vohradsky
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018869:Heat-Shock Response / Q000235:genetics; D048372:Streptomyces coelicolor / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism* / Q000502:physiology; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins