Genetic drift at expanding frontiers promotes gene segregation

Abstract

Competition between random genetic drift and natural selection plays a central role in evolution: Whereas non-beneficial mutations often prevail in small populations by chance, mutations that sweep through large populations typically confer a selective advantage. Here, however, we observe chance effects during range expansions that dramatically alter the gene pool even in large microbial populations. Initially well-mixed populations of two fluorescently labeled strains of Escherichia coli develop well-defined, sector-like regions with fractal boundaries in expanding colonies. The formation of these regions is driven by random fluctuations that originate in a thin band of pioneers at the expanding frontier. A comparison of bacterial and yeast colonies (Saccharomyces cerevisiae) suggests that this large-scale genetic sectoring is a generic phenomenon that may provide a detectable footprint of past range expansions.

Please visit http://www.pnas.org/content/104/50/19926.abstract for published article

References in corpus (1)

• Gene surfing

Cited by in corpus (16)

• Growing interfaces uncover universal fluctuations behind scale invariance
• Selective sweeps in growing microbial colonies
• Demographic noise can reverse the direction of deterministic selection
• Biphasic, Lyotropic, Active Nematics
• Chemical warfare and survival strategies in bacterial range expansions
• Radial Domany-Kinzel Models with Mutation and Selection
• Memory and universality in interface growth
• Stochastic mechanisms forming large clones during colonisation of new areas
• Mobility, fitness collection, and the breakdown of cooperation
• Kinetic roughening of aggregates of patchy colloids with strong and weak bonds
• Growth-induced breaking and unbreaking of ergodicity in fully-connected spin systems
• Kinetic interfaces of patchy particles
• Effects of population growth on the success of invading mutants
• Escherichia coli as a model active colloid: a practical introduction
• Life at the front of an expanding population
• Supplementary information for "Selective sweeps in growing microbial colonies"