Forecasting of phenotypic and genetic outcomes of experimental evolution inPseudomonas syringaeandPseudomonas savastanoi

Author:

Pentz Jennifer T.ORCID,Biswas Aparna,Alsaed BasselORCID,Lind Peter A.ORCID

Abstract

ABSTRACTMicrobial experimental evolution is commonly highly repeatable under identical conditions, indicating a potential for short-term evolutionary forecasting. However, it is unclear to what extent evolutionary predictions can be extrapolated to related species adapting in similar environments, which would enable direct testing of general forecasting models and biological assumptions. To further develop a model system for evolutionary forecasting based on adaptation to static culture conditions, we experimentally tested previous predictions forPseudomonas syringaeandPseudomonas savastanoi. In addition to sequence divergence, these species also differ in their repertoire of diguanylate cyclases that can be mutationally activated to produce the adaptive wrinkly spreader (WS) phenotype and genes for biosynthesis of exopolysaccharides. After experimental evolution, we isolated 32 independent WS mutants forP. syringaeand 37 WS mutants forP. savastanoithat had increased ability to colonize the air-liquid interface and reduced motility. As predicted, most mutants had mutations in thewspoperon followed by rarer promoter mutations upstream of uncharacterized diguanylate cyclases. Surprisingly, no mutations were found inwspF,the most commonly mutated gene in the previously characterized species, which was explained by differences in relative fitness. While prediction of mutated regions was largely successful for WspA, mutations in WspE had a divergent pattern for both species. Surprisingly, deletion of known exopolysaccharide loci previously shown to contribute to the adaptive WS phenotype in other species did not reduce fitness, suggesting the presence of additional adhesive components under c-di-GMP control. This study shows that evolutionary forecasts can be extended to related species, but that differences in the genotype-phenotype-fitness map and mutational biases limit predictability on a detailed molecular level.Author summaryBiological evolution is often observed to be repeatable in the short-term, which suggests that it might be possible to forecast and ultimately steer evolution. Evolutionary processes are fundamental to biology but are also central to major societal problems, including antibiotic resistance, cancer, and adaptation to climate change. Experimental evolution with microbes makes it possible to study evolutionary processes in real-time over many generations to allow direct tests of evolutionary forecasts. However, a fundamental problem is that predictive models are usually based on previous experimental data which limits the novelty of the prediction beyond simple repeatability. A more challenging issue is to predict to what degree similar species evolve in similar ways in similar environments. Here we show that one of the best characterized bacterial experimental evolution model systems, biofilm formation at the surface of static tubes inPseudomonas, can be extended to related species evolving in similar environments. This allowed us to directly test previous evolutionary forecasts to show that similar phenotypes evolved in similar environments, but that predictions of molecular details often fail. This study also elucidates the causes for failed forecasts to allow continuous improvements in predictive models and to delineate the limits of evolutionary forecasting.

Publisher

Cold Spring Harbor Laboratory

Cited by 1 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3