Adaptive prediction of environmental changes by microorganisms.

Area of Science:

• Microbiology
• Evolutionary Biology
• Molecular Biology

Background:

• Microbial habitats can be unpredictable or predictable, allowing for adaptation to environmental changes.
• Organisms may evolve to anticipate environmental stimuli based on their temporal order, similar to Pavlovian conditioning.

Purpose of the Study:

• To investigate environmental change anticipation in model microorganisms, Escherichia coli and Saccharomyces cerevisiae.
• To determine if anticipation is an adaptive trait and understand its molecular basis.

Main Methods:

• Studied Escherichia coli and Saccharomyces cerevisiae under controlled environmental stimuli.
• Utilized laboratory evolution experiments to observe changes in conditioned responses.
• Analyzed gene regulatory networks to understand the molecular mechanisms of anticipation.

Main Results:

• Demonstrated that pre-exposure to an early environmental stimulus enhances fitness when a subsequent stimulus is encountered.
• Observed a loss of conditioned response in Escherichia coli strains exposed only to the initial stimulus.
• Revealed that regulatory networks embed the temporal order of stimuli, with early stimuli pre-inducing genes for later ones.

Conclusions:

• Environmental anticipation is an adaptive trait selected for during evolution in microorganisms.
• The temporal order of environmental stimuli is integrated into microbial regulatory networks.
• Anticipation of environmental changes may be a ubiquitous biological phenomenon.