title: A constant size extension drives bacterial cell size homeostasis.
abstract: Cell size control is an intrinsic feature of the cell cycle. In bacteria, cell growth and division are thought to be coupled through a cell size threshold. Here, we provide direct experimental evidence disproving the critical size paradigm. Instead, we show through single-cell microscopy and modeling that the evolutionarily distant bacteria Escherichia coli and Caulobacter crescentus achieve cell size homeostasis by growing, on average, the same amount between divisions, irrespective of cell length at birth. This simple mechanism provides a remarkably robust cell size control without the need of being precise, abating size deviations exponentially within a few generations. This size homeostasis mechanism is broadly applicable for symmetric and asymmetric divisions, as well as for different growth rates. Furthermore, our data suggest that constant size extension is implemented at or close to division. Altogether, our findings provide fundamentally distinct governing principles for cell size and cell-cycle control in bacteria.
authors.affiliation: Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA.
authors.forename: Manuel
authors.initials: M
authors.lastname: Campos
authors.affiliation: Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA.
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Surovtsev
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
authors.forename: Setsu
authors.initials: S
authors.lastname: Kato
authors.affiliation: Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Paintdakhi
authors.affiliation: Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
authors.forename: Bruno
authors.initials: B
authors.lastname: Beltran
authors.affiliation: Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Ebmeier
authors.affiliation: Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Microbial Pathogenesis, Yale Medical School, Yale University, New Haven, CT 06520, USA. Electronic address: christine.jacobs-wagner@yale.edu.
authors.forename: Christine
authors.initials: C
authors.lastname: Jacobs-Wagner
mesh_terms: D016935:Caulobacter crescentus / Q000166:cytology* / Q000254:growth & development / Q000502:physiology*; D002453:Cell Cycle; D004926:Escherichia coli / Q000166:cytology* / Q000254:growth & development / Q000502:physiology*; D006706:Homeostasis