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SUMMARY:Stochasticity and Bistability in Horizontal Transfer Control of a 
 Genomic Island in Pseudomonas
DTSTART:20100218T121500
DTSTAMP:20260510T040515Z
UID:ae1a031930a6738c3907809dfc19838e205662160e52c5bcb7aade5a
CATEGORIES:Conferences - Seminars
DESCRIPTION:Marco Minoia\, University of Lausanne\nGenomic islands (GEI) c
 omprise a recently recognized large family of potentially mobile DNA eleme
 nts. Because of their wide distribution\, GEI form an important model to t
 est various hypotheses on HGT in general. One of the key questions that ha
 ve escaped much attention concerns the regulatory decisions controlling HG
 T at the level of the individual bacterial cell. This seems surprising giv
 en the typical low frequencies (1% or less) for HGT in bacterial populatio
 ns (1)\, and suggests that cells\, despite their clonality\, are undergoin
 g 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 re
 sult of which is that only a few percent of cells in a population will exc
 ise ICEclc and launch transfer (2). Stochastic processes have been implica
 ted before in producing bistable phenotypic transitions\, such as sporulat
 ion and competence development\, but never before in horizontal gene trans
 fer (HGT). Bistability is instigated during stationary phase at the level 
 of expression of an activator protein InrR that lays encoded on ICEclc\, a
 nd then faithfully propagated to a bistable expression of the IntB13 integ
 rase\, the enzyme responsible for excision and integration of the ICEclc. 
 References: 1 Sørensen et al. Nat Rev Microbiol (2005) 3:700–710. 2 Min
 oia M et al. Proc Natl Acad Sci U S A. (2008) 105:20792-20797
LOCATION:SV 1717A
STATUS:CONFIRMED
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