Imperial College London

DrNicholasCroucher

Faculty of MedicineSchool of Public Health

Reader in Bacterial Genomics
 
 
 
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Contact

 

+44 (0)20 7594 3820n.croucher

 
 
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Location

 

1104Sir Michael Uren HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Croucher:2016:10.1371/journal.pbio.1002394,
author = {Croucher, NJ and Mostowy, R and Wymant, C and Turner, P and Bentley, SD and Fraser, C},
doi = {10.1371/journal.pbio.1002394},
journal = {PLOS Biology},
title = {Horizontal DNA transfer mechanisms of bacteria as weapons of intragenomic conflict},
url = {http://dx.doi.org/10.1371/journal.pbio.1002394},
volume = {14},
year = {2016}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Horizontal DNA transfer (HDT) is a pervasive mechanism of diversification in many microbial species, but its primary evolutionary role remains controversial. Much recent research has emphasised the adaptive benefit of acquiring novel DNA, but here we argue instead that intragenomic conflict provides a coherent framework for understanding the evolutionary origins of HDT. To test this hypothesis, we developed a mathematical model of a clonally descended bacterial population undergoing HDT through transmission of mobile genetic elements (MGEs) and genetic transformation. Including the known bias of transformation toward the acquisition of shorter alleles into the model suggested it could be an effective means of counteracting the spread of MGEs. Both constitutive and transient competence for transformation were found to provide an effective defence against parasitic MGEs; transient competence could also be effective at permitting the selective spread of MGEs conferring a benefit on their host bacterium. The coordination of transient competence with cell-cell killing, observed in multiple species, was found to result in synergistic blocking of MGE transmission through releasing genomic DNA for homologous recombination while simultaneously reducing horizontal MGE spread by lowering the local cell density. To evaluate the feasibility of the functions suggested by the modelling analysis, we analysed genomic data from longitudinal sampling of individuals carrying Streptococcus pneumoniae. This revealed the frequent within-host coexistence of clonally descended cells that differed in their MGE infection status, a necessary condition for the proposed mechanism to operate. Additionally, we found multiple examples of MGEs inhibiting transformation through integrative disruption of genes encoding the competence machinery across many species, providing evidence of an ongoing "arms race." Reduced rates of transformation have also been observed in cells infected by MGEs t
AU - Croucher,NJ
AU - Mostowy,R
AU - Wymant,C
AU - Turner,P
AU - Bentley,SD
AU - Fraser,C
DO - 10.1371/journal.pbio.1002394
PY - 2016///
SN - 1545-7885
TI - Horizontal DNA transfer mechanisms of bacteria as weapons of intragenomic conflict
T2 - PLOS Biology
UR - http://dx.doi.org/10.1371/journal.pbio.1002394
UR - http://www.ncbi.nlm.nih.gov/pubmed/26934590
UR - http://hdl.handle.net/10044/1/30969
VL - 14
ER -