Stochasticity and Bistability in Horizontal Transfer Control of a Genomic Island in Pseudomonas
Event details
| Date | 18.02.2010 |
| Hour | 12:15 |
| Speaker | Marco Minoia, University of Lausanne |
| Location |
SV 1717A
|
| Category | Conferences - Seminars |
Genomic islands (GEI) comprise a recently recognized large family of potentially mobile DNA elements. Because of their wide distribution, GEI form an important model to test various hypotheses on HGT in general. One of the key questions that have escaped much attention concerns the regulatory decisions controlling HGT at the level of the individual bacterial cell. This seems surprising given the typical low frequencies (1% or less) for HGT in bacterial populations (1), and suggests that cells, despite their clonality, are undergoing some sort of phenotypic variation into transfer-proficient and transfer-silent subpopulations. The self-transfer of ICEclc, a GEI in Pseudomonas knackmussii B13 is controlled by a series of stochastic processes, the result of which is that only a few percent of cells in a population will excise ICEclc and launch transfer (2). Stochastic processes have been implicated before in producing bistable phenotypic transitions, such as sporulation and competence development, but never before in horizontal gene transfer (HGT). Bistability is instigated during stationary phase at the level of expression of an activator protein InrR that lays encoded on ICEclc, and then faithfully propagated to a bistable expression of the IntB13 integrase, the enzyme responsible for excision and integration of the ICEclc. References: 1 Sørensen et al. Nat Rev Microbiol (2005) 3:700–710. 2 Minoia M et al. Proc Natl Acad Sci U S A. (2008) 105:20792-20797
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Practical information
- General public
- Free
Organizer
- Melanie Blokesch
Contact
- Caroline Guinchard