A Model for the Evolutionary Dynamics of Cross-Feeding Polymorphisms in Microorganisms

Abstract Understanding the mechanism of evolutionary diversification is the core of evolutionary biology. Microorganisms constitute a promising model system for observing various processes directly in the laboratory. One of the main existing paradigms of microbial diversity is the evolution of cross-feeding polymorphisms in which strains specialized for major resources coexist with heterogeneous hybridization lines specialized for waste caused by depletion of major resources.

In this paper, we describe the ecological evolution feedback loop in social microbial species. Our aim is to investigate whether ecological evolutionary feedback plays a role in the evolutionary dynamics of cooperative traits and how they affect the ecological characteristics of the collective evolutionary population . In order to explore these ecological evolutionary feedback loops through experiments we utilized synergistic growth of budding yeast in sucrose. This cooperative growth is mediated by a single cooperative gene, SUC2, which encodes invertase that degrades sucrose into glucose and fructose. Periplasmic space secreted by invertase between cell membrane and cell wall

Feedback between the group and the evolutionary dynamics determines the fate of the social microbial community

The multi-day proliferation dilution cycle shows that the dynamics of the evolution of the co-genes may have a significant influence on the dynamics of the population. In the absence of evolutionary dynamics (diluted only 667 times per day), the yeast population consisting solely of cooperative cells converges to a rapidly balanced population size. (C) Four different populations of mixtures of SUC2 vector and deletion mutants were subjected to an 8-day growth dilution cycle. Population starts with population density and SUC2 frequency of population. The evolutionary dynamics of the four populations (D) and (C) are represented by the same color. A plot of the dynamics of population and evolution shows seemingly unstable and non-monotonic behavior. By constructing the ecologically evolutionary topological space formed by the size and frequency of the population of SUC2 genes in the (E) population, we find that the four populations of (CD) follow a clearly defined trajectory I found out.

Feedback between the group and the evolutionary dynamics determines the fate of the social microbial community