Evolution of Microbial Growth Traits Under Serial Dilution

Copyright © 2020 by the Genetics Society of America..

Selection of mutants in a microbial population depends on multiple cellular traits. In serial-dilution evolution experiments, three key traits are the lag time when transitioning from starvation to growth, the exponential growth rate, and the yield (number of cells per unit resource). Here, we investigate how these traits evolve in laboratory evolution experiments using a minimal model of population dynamics, where the only interaction between cells is competition for a single limiting resource. We find that the fixation probability of a beneficial mutation depends on a linear combination of its growth rate and lag time relative to its immediate ancestor, even under clonal interference. The relative selective pressure on growth rate and lag time is set by the dilution factor; a larger dilution factor favors the adaptation of growth rate over the adaptation of lag time. The model shows that yield, however, is under no direct selection. We also show how the adaptation speeds of growth and lag depend on experimental parameters and the underlying supply of mutations. Finally, we investigate the evolution of covariation between these traits across populations, which reveals that the population growth rate and lag time can evolve a nonzero correlation even if mutations have uncorrelated effects on the two traits. Altogether these results provide useful guidance to future experiments on microbial evolution.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:215

Enthalten in:

Genetics - 215(2020), 3 vom: 04. Juli, Seite 767-777

Sprache:

Englisch

Beteiligte Personen:

Lin, Jie [VerfasserIn]
Manhart, Michael [VerfasserIn]
Amir, Ariel [VerfasserIn]

Links:

Volltext

Themen:

Adaptation rate
Fixation probability
Journal Article
Microbial evolution
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Anmerkungen:

Date Completed 24.06.2021

Date Revised 24.06.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1534/genetics.120.303149

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM309500729