The evolutionary emergence of stochastic phenotype switching in bacteria.

Autor: Rainey PB; New Zealand Institute for Advanced Study and Allan Wilson Centre for Molecular Ecology & Evolution, Massey University at Albany, Auckland, New Zealand. rainey@evolbio.mpg.de, Beaumont HJ, Ferguson GC, Gallie J, Kost C, Libby E, Zhang XX
Jazyk: angličtina
Zdroj: Microbial cell factories [Microb Cell Fact] 2011 Aug 30; Vol. 10 Suppl 1, pp. S14. Date of Electronic Publication: 2011 Aug 30.
DOI: 10.1186/1475-2859-10-S1-S14
Abstrakt: Stochastic phenotype switching - or bet hedging - is a pervasive feature of living systems and common in bacteria that experience fluctuating (unpredictable) environmental conditions. Under such conditions, the capacity to generate variable offspring spreads the risk of being maladapted in the present environment, against offspring likely to have some chance of survival in the future. While a rich subject for theoretical studies, little is known about the selective causes responsible for the evolutionary emergence of stochastic phenotype switching. Here we review recent work - both theoretical and experimental - that sheds light on ecological factors that favour switching types over non-switching types. Of particular relevance is an experiment that provided evidence for an adaptive origin of stochastic phenotype switching by subjecting bacterial populations to a selective regime that mimicked essential features of the host immune response. Central to the emergence of switching types was frequent imposition of 'exclusion rules' and 'population bottlenecks' - two complementary faces of frequency dependent selection. While features of the immune response, exclusion rules and bottlenecks are likely to operate in many natural environments. Together these factors define a set of selective conditions relevant to the evolution of stochastic switching, including antigenic variation and bacterial persistence.
Databáze: MEDLINE