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...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3380070?pdf=render |
| _version_ | 1818837533260251136 |
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| 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. |
| first_indexed | 2024-12-19T03:24:01Z |
| format | Article |
| id | doaj.art-7c8d26e2692e43508d55a49935b1e87d |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-19T03:24:01Z |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-7c8d26e2692e43508d55a49935b1e87d2022-12-21T20:37:42ZengPublic 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.http://europepmc.org/articles/PMC3380070?pdf=render |
| 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 | http://europepmc.org/articles/PMC3380070?pdf=render |
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