This Cell Is on Fire: The Effects of Heat Shock Adaptation
Faculty Mentor Information
Dr. Chris Marx (Mentor), University of Idaho
Abstract
Bacterial populations face a myriad of stressors they must adapt to in order to avoid extinction. However, adaptation to one environment can result in either beneficial or detrimental fitness effects in other environments. Populations face frequently changing environments and must be able to balance the collateral effects of adaptation to optimize fitness over long timescales. In this work, we use Methylobacterium extorquens as a model organism to ask how bacterial populations adapt to transient heat shock stress and the collateral effects of this adaptation. Heat shock is a stressor frequently faced by microbes, both in nature and in hosts. We discover a dual cost of heat shock stress in populations; death, and cell damage induced lag among survivors. We evolve Methylobacterium extorquens under heat shock stress for ~35 generations. We find evidence of rapid evolution, where even in this short timescale, we see massive increases in fitness among all replicate populations. This suggests that adaptation to a new transient environmental stressor is accessible and rapid. In future work, we will aim to characterize the collateral effects of heat shock adaptation, the physiological route to increased fitness, and the genetic basis of adaptive changes.
This Cell Is on Fire: The Effects of Heat Shock Adaptation
Bacterial populations face a myriad of stressors they must adapt to in order to avoid extinction. However, adaptation to one environment can result in either beneficial or detrimental fitness effects in other environments. Populations face frequently changing environments and must be able to balance the collateral effects of adaptation to optimize fitness over long timescales. In this work, we use Methylobacterium extorquens as a model organism to ask how bacterial populations adapt to transient heat shock stress and the collateral effects of this adaptation. Heat shock is a stressor frequently faced by microbes, both in nature and in hosts. We discover a dual cost of heat shock stress in populations; death, and cell damage induced lag among survivors. We evolve Methylobacterium extorquens under heat shock stress for ~35 generations. We find evidence of rapid evolution, where even in this short timescale, we see massive increases in fitness among all replicate populations. This suggests that adaptation to a new transient environmental stressor is accessible and rapid. In future work, we will aim to characterize the collateral effects of heat shock adaptation, the physiological route to increased fitness, and the genetic basis of adaptive changes.