Selective heterogeneity in exoprotease production by Bacillus subtilis.

Bacteria have elaborate signalling mechanisms to ensure a behavioural response that is most likely to enhance survival in a changing environment. It is becoming increasingly apparent that as part of this response, bacteria are capable of cell differentiation and can generate multiple, mutually exclu...

Full description

Saved in:
Bibliographic Details
Main Authors: Fordyce A Davidson, Chung Seon-Yi, Nicola R Stanley-Wall
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2012-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0038574&type=printable
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850224808593195008
author Fordyce A Davidson
Chung Seon-Yi
Nicola R Stanley-Wall
author_facet Fordyce A Davidson
Chung Seon-Yi
Nicola R Stanley-Wall
author_sort Fordyce A Davidson
collection DOAJ
description Bacteria have elaborate signalling mechanisms to ensure a behavioural response that is most likely to enhance survival in a changing environment. It is becoming increasingly apparent that as part of this response, bacteria are capable of cell differentiation and can generate multiple, mutually exclusive co-existing cell states. These cell states are often associated with multicellular processes that bring benefit to the community as a whole but which may be, paradoxically, disadvantageous to an individual subpopulation. How this process of cell differentiation is controlled is intriguing and remains a largely open question. In this paper, we consider an important aspect of cell differentiation that is known to occur in the gram-positive bacterium Bacillus subtilis: we investigate the role of two master regulators DegU and Spo0A in the control of extra-cellular protease production. Recent work in this area focussed the on role of DegU in this process and suggested that transient effects in protein production were the drivers of cell-response heterogeneity. Here, using a combination of mathematical modelling, analysis and stochastic simulations, we provide a complementary analysis of this regulatory system that investigates the roles of both DegU and Spo0A in extra-cellular protease production. In doing so, we present a mechanism for bimodality, or system heterogeneity, without the need for a bistable switch in the underlying regulatory network. Moreover, our analysis leads us to conclude that this heterogeneity is in fact a persistent, stable feature. Our results suggest that system response is divided into three zones: low and high signal levels induce a unimodal or undifferentiated response from the cell population with all cells OFF and ON, respectively for exoprotease production. However, for intermediate levels of signal, a heterogeneous response is predicted with a spread of activity levels, representing typical "bet-hedging" behaviour.
format Article
id doaj-art-7c8d26e2692e43508d55a49935b1e87d
institution OA Journals
issn 1932-6203
language English
publishDate 2012-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-7c8d26e2692e43508d55a49935b1e87d2025-08-20T02:05:32ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0176e3857410.1371/journal.pone.0038574Selective heterogeneity in exoprotease production by Bacillus subtilis.Fordyce A DavidsonChung Seon-YiNicola R Stanley-WallBacteria have elaborate signalling mechanisms to ensure a behavioural response that is most likely to enhance survival in a changing environment. It is becoming increasingly apparent that as part of this response, bacteria are capable of cell differentiation and can generate multiple, mutually exclusive co-existing cell states. These cell states are often associated with multicellular processes that bring benefit to the community as a whole but which may be, paradoxically, disadvantageous to an individual subpopulation. How this process of cell differentiation is controlled is intriguing and remains a largely open question. In this paper, we consider an important aspect of cell differentiation that is known to occur in the gram-positive bacterium Bacillus subtilis: we investigate the role of two master regulators DegU and Spo0A in the control of extra-cellular protease production. Recent work in this area focussed the on role of DegU in this process and suggested that transient effects in protein production were the drivers of cell-response heterogeneity. Here, using a combination of mathematical modelling, analysis and stochastic simulations, we provide a complementary analysis of this regulatory system that investigates the roles of both DegU and Spo0A in extra-cellular protease production. In doing so, we present a mechanism for bimodality, or system heterogeneity, without the need for a bistable switch in the underlying regulatory network. Moreover, our analysis leads us to conclude that this heterogeneity is in fact a persistent, stable feature. Our results suggest that system response is divided into three zones: low and high signal levels induce a unimodal or undifferentiated response from the cell population with all cells OFF and ON, respectively for exoprotease production. However, for intermediate levels of signal, a heterogeneous response is predicted with a spread of activity levels, representing typical "bet-hedging" behaviour.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0038574&type=printable
spellingShingle Fordyce A Davidson
Chung Seon-Yi
Nicola R Stanley-Wall
Selective heterogeneity in exoprotease production by Bacillus subtilis.
PLoS ONE
title Selective heterogeneity in exoprotease production by Bacillus subtilis.
title_full Selective heterogeneity in exoprotease production by Bacillus subtilis.
title_fullStr Selective heterogeneity in exoprotease production by Bacillus subtilis.
title_full_unstemmed Selective heterogeneity in exoprotease production by Bacillus subtilis.
title_short Selective heterogeneity in exoprotease production by Bacillus subtilis.
title_sort selective heterogeneity in exoprotease production by bacillus subtilis
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0038574&type=printable
work_keys_str_mv AT fordyceadavidson selectiveheterogeneityinexoproteaseproductionbybacillussubtilis
AT chungseonyi selectiveheterogeneityinexoproteaseproductionbybacillussubtilis
AT nicolarstanleywall selectiveheterogeneityinexoproteaseproductionbybacillussubtilis