Bacterial ageing in the absence of external stressors

Łapińska, U., Glover, G., Capilla-Lasheras, P. , Young, A. J. and Pagliara, S. (2019) Bacterial ageing in the absence of external stressors. Philosophical Transactions of the Royal Society B: Biological Sciences, 374(1786), 20180442. (doi: 10.1098/rstb.2018.0442) (PMID:31587633) (PMCID:PMC6792439)

Abstract

Evidence of ageing in the bacterium Escherichia coli was a landmark finding in senescence research, as it suggested that even organisms with morphologically symmetrical fission may have evolved strategies to permit damage accumulation. However, recent work has suggested that ageing is only detectable in this organism in the presence of extrinsic stressors, such as the fluorescent proteins and strong light sources typically used to excite them. Here we combine microfluidics with brightfield microscopy to provide evidence of ageing in E. coli in the absence of these stressors. We report (i) that the doubling time of the lineage of cells that consistently inherits the ‘maternal old pole’ progressively increases with successive rounds of cell division until it reaches an apparent asymptote, and (ii) that the parental cell divides asymmetrically, with the old pole daughter showing a longer doubling time and slower glucose accumulation than the new pole daughter. Notably, these patterns arise without the progressive accumulation or asymmetric partitioning of observable misfolded-protein aggregates, phenomena previously hypothesized to cause the ageing phenotype. Our findings suggest that ageing is part of the naturally occurring ecologically-relevant phenotype of this bacterium and highlight the importance of alternative mechanisms of damage accumulation in this context.

• Item Type: Articles
• Additional Information: U.L. was supported through a MRC Proximity to Discovery EXCITEME2 grant (MCPC17189) awarded to S.P. and A.J.Y. G.G. was supported by an EPSRC DTP PhD studentship (EP/M506527/1). P.C.-L. was supported by the BBSRC-funded South West Biosciences Doctoral Training Partnership (BB/M009122/1). This work was further supported by a Royal Society Research Grant (RG180007) and a Wellcome Trust Strategic Seed Corn Fund (WT097835/Z/11/Z) awarded to S.P.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Capilla Lasheras, Dr Pablo
• Authors: Łapińska, U., Glover, G., Capilla-Lasheras, P., Young, A. J., and Pagliara, S.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Philosophical Transactions of the Royal Society B: Biological Sciences
• Publisher: The Royal Society
• ISSN: 0962-8436
• ISSN (Online): 1471-2970
• Published Online: 07 October 2019
• Copyright Holders: Copyright © 2019 The Authors
• First Published: First published in Philosophical Transactions of the Royal Society B: Biological Sciences 374(1786): 20180442
• Publisher Policy: Reproduced under a Creative Commons License