H2020Индивидуална стипендия2017–2019

ESSEVOL · Adapting to Change: Experimental Evolution of Environmental Sensing Systems in Bacteria

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2017-12-01 → 2019-11-30
Финансиране от ЕС: 183 455 €
Участници: 1
Схема: MSCA-IF

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Накратко на български

Бактериите и способността им да се адаптират към променяща се среда се изследват чрез проследяване на тяхната подвижност през стотици поколения. Това помага да се разбере как живите организми развиват системи за усещане и реакция при климатични промени.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Adapting to Change: Experimental Evolution of Environmental Sensing Systems in Bacteria

Understanding how life copes with ever-changing conditions has intrigued biologists for decades, and it is currently in the spotlight due to global climate change. One solution that organisms have adopted repeatedly is the evolution of systems that allow them to sense and respond to their surroundings. Environmental sensing systems (ESS) can exhibit high degrees of complexity and are pervasive throughout the Tree of Life – a testimony of their evolutionary success. While theory has identified a range of conditions that promote the emergence of ESS, empirical tests are scarce, largely due to the practical difficulties of observing these processes in real time. Here, we addressed this challenge by taking an laboratory evolution approach, in which we exposed bacteria for hundreds of generations to fluctuating selection for and against motility, a readily tractable behaviour that allows bacteria to find favourable growth conditions and move away from bad ones. The experiments show that bacterial populations are able to evolve a variety of adaptive strategies in response to fluctuating conditions, including the emergence of specialists (non-motile and extra-motile) and generalists (intermediate-motile and conditionally-motile). These observations match the theoretical predictions, but only qualitatively. Indeed, the explosion of diversity is well captured by simple theoretical models. However, conditionally-motile phenotypes (that is, mutants with novel ESS) are expected to dominate this scenario, while in reality they only were found at very low frequencies. Further analyses explained this discrepancy as due to the fact that behaviour-altering mutations are typically of small effect and can be costly in non-selective environments. In other words, while many mutational paths towards conditionally-motile phenotypes may exist, only a few of them can be easily trodden. These insights advance our understanding of both the constraints and facilitators of behavioural evolution in bacteria, contributing to a knowledge base that may help in the design of anti-virulence drugs and microbe-based biosensors and bioreporters.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Background: Coping with ever-changing conditions is a problem common to most living things. One solution that organisms have come up with is the evolution of systems that allow them to sense and respond to their surroundings. Despite being usually complex and costly to maintain, sensing devices are widespread throughout the Tree of Life, which has puzzled researchers for years. Theory has identified a number of scenarios that promote the emergence of environmental sensing systems. Yet, most aspects of their origin and evolution remain obscure; largely due to the practical difficulties of observing these processes in real time. Here I propose to fill this gap by combining experimental evolution with the Host Group's expertise on the molecular regulation of bacterial behaviour. Methodology: The plan is to couple sudden changes in growth conditions with arbitrary environmental cues (e.g., toxic metals) to select for bacteria capable of reading these cues and altering their behaviour accordingly. I will target a well-studied behaviour: motility, which plays a key role in nature allowing bacteria to find good conditions and move away from threats. Using this setting, I will test decades-long hypotheses about the genetic and ecological factors that shape the emergence of novel sensing systems. Later, I will exploit the power of new DNA sequencing techniques to work out how genetic changes drive the new behaviours. Impact: This research will shed light on how readily novel sensing systems can evolve, thus contributing to efforts to understand pressing issues such as the emergence of multi-drug resistance pathogens or the response of natural populations to the current global change. Outcomes could also help in the design of novel antimicrobial drugs and microbe-based reporters with applications in bioremediation (e.g., detection of contaminants), biotechnology (e.g. monitoring of industrial processes) and in Public Health (e.g., detection of pathogens in water supplies).

Оригинален текст от CORDIS (на английски).

Участници

IMPERIAL COLLEGE OF SCIENCE TECHNOLOGY AND MEDICINE · LondonКоординаторОбединеното кралство