[Answer] phase variation

Answer: switch on or off the expression of some bacterial cell component
phase variation
In biology phase variation is a method for dealing with rapidly varying environments without requiring random mutation. It involves the variation of protein expression frequently in an on-off fashion within different parts of a bacterial population. As such the phenotype can switch at frequencies that are much higher than classical mutation rates. Phase variation contributes to virulence by generating heterogeneity. Although it has been most commonly studied in the context of immune evasion
This mechanism known as phase variation results in a skewed distribution of phenotypic characteristics within a bacterial population. Bacteria may also undergo antigenic variation in which they display qualitative differences in cell surface molecules that can be detected by specific antisera.
Phase variation (PV) is a phenomenon common to a variety of bacterial species for niche adaption and survival in challenging environments. Among Campylobacter species PV depends on the presence of intergenic and intragenic hypermutable G/C homopolymeric tracts. The presence of phase-variable genes is of especial interest for species that cause foodborne or zoonotic infections in humans.
Phase variationis an immune evasion technique employed by various types of bacteria including Salmonella species. It involves the switching of surface antigens to evade specific adaptive immune systemresponses. Full article >>>. Identification of mutants with increased phasevariationfrequencies.
Phase variation in general refers to a reversible switch between an “all-or-none”…

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