Kin discrimination and outer membrane exchange in Myxococcus xanthus : Experimental analysis of a natural population

In some species of myxobacteria, adjacent cells sufficiently similar at the adhesin protein TraA can exchange components of their outer membranes. The primary benefits of such outer membrane exchange (OME) in natural populations are unclear, but in some OME interactions, transferred OM content can include SitA toxins that kill OME participants lacking an appropriate immunity gene. Such OME-dependent toxin transfer across Myxococcus xanthus strains that differ only in their sitBAI toxin/antitoxin cassette can mediate inter-strain killing and generate colony-merger incompatibilities (CMIs)-inter-colony border phenotypes between distinct genotypes that differ from respective self-self colony interfaces. Here we ask whether OME-dependent toxin transfer is a common cause of prevalent CMIs and antagonisms between M. xanthus natural isolates identical at TraA. We disrupted traA in eleven isolates from a cm-scale soil population and assayed whether traA disruption eliminated or reduced CMIs between swarming colonies or antagonisms between strains in mixed cultures. Among 33 isolate pairs identical at traA that form clear CMIs, in no case did functional disruption of traA in one partner detectably alter CMI phenotypes. Further, traA disruption did not alleviate strong antagonisms observed during starvation-induced fruiting-body development in seven pairs of strains identical at traA. Collectively, our results suggest that most mechanisms of interference competition and inter-colony kin discrimination in natural populations of myxobacteria do not require OME. Finally, our experiments also indicate that several closely related laboratory reference strains kill some natural isolates by toxins delivered by a shared, OME-independent type VI secretion system (T6SS), suggesting that some antagonisms between sympatric natural isolates may also involve T6SS toxins.

Errataetall:

ErratumIn: PLoS One. 2020 Jan 30;15(1):e0228697. - PMID 31999808

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:14

Enthalten in:

PloS one - 14(2019), 11 vom: 01., Seite e0224817

Sprache:

Englisch

Beteiligte Personen:

Cossey, Sarah M [VerfasserIn]
Yu, Yuen-Tsu Nicco [VerfasserIn]
Cossu, Laura [VerfasserIn]
Velicer, Gregory J [VerfasserIn]

Links:

Volltext

Themen:

Bacterial Outer Membrane Proteins
Bacterial Toxins
Journal Article
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 17.03.2020

Date Revised 17.03.2020

published: Electronic-eCollection

ErratumIn: PLoS One. 2020 Jan 30;15(1):e0228697. - PMID 31999808

Citation Status MEDLINE

doi:

10.1371/journal.pone.0224817

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM303770767