第51回生態適応セミナー (Bセミナー)

     
  日時:1月6日(月曜日)16:30 – 18:00  
  場所:片平キャンパス プロジェクト総合研究棟講義室105  
     

講師:Dr. Ryo Miyazaki (Department of Fundamental Microbiology, University of Lausanne, Switzerland)

     
  Stochasticity and bistability of the ICEclc genomic island  
     
 

Understanding the evolutionary mechanisms which enable bacteria to acquire new functions for the degradation of toxic and xenobiotic substances in the environment would be important from both environmental and biological viewpoints. Recent genome sequencing efforts have revealed that bacterial chromosomes typically contain a number of large DNA regions possibly acquired via horizontal gene transfer. Such foreign segments, named genomic islands (GEIs), confer several traits to the host bacteria with potential adaptive benefits, such as antibiotic resistance, plant symbiosis or aromatic compound degradation. The model we deploy to study the horizontal transfer of GEI is ICEclc, a 103-kb GEI first discovered in Pseudomonas knackmussii B13. ICEclc confers to its host the ability to metabolize 3-chlorobenzoate and 2-aminophenol. The most interesting discovery in the “life-style” of ICEclc is that a series of stochastic processes induces a bistable program involved in ICEclc self-transfer as well as subsequent cell death. Furthermore, our recent research found that ICEclc employs the unique transfer system which could provide an evolutionary advantage for distribution.