Current Insights into Phase and Antigenic Variation in Mycoplasmas
from: Mollicutes: Molecular Biology and Pathogenesis (Edited by: Glenn F. Browning and Christine Citti). Caister Academic Press, U.K. (2014)
Despite their small genomes and the lack of a protecting cell wall, many Mycoplasma species successfully establish chronic infections in diverse hosts, even in the presence of a specific immune response. This success is, in part, attributable to genetic switches that rapidly alter the expression, size or structure of their surface exposed proteins. These stochastic events create highly versatile and dynamic membranes, enabling these bacteria to escape the host immune response and enhance bacterial-host interactions essential for survival. This chapter provides an overview of the current knowledge of phase- and antigenic-variation in Mycoplasmas and documents on the diverse genetic mechanisms, such as reversible point mutation, slipped-strand mispairing and DNA rearrangement via site-specific or homologous recombination that lead to antigenic variation of distinct proteins in individual Mycoplasma species. The chapter contains one diagram illustrating the causes and effects of antigenic variation, three figures illustrating diverse mechanisms of phase variation and one table describing gene loci from Mycoplasma species that are affected by phase variation read more ...