Bacterial division. Mechanical crack propagation drives millisecond daughter cell separation in Staphylococcus aureus.
When Staphylococcus aureus undergoes cytokinesis, it builds a septum, generating two hemispherical daughters whose cell walls are only connected via a narrow peripheral ring. We found that resolution of this ring occurred within milliseconds ("popping"), without detectable changes in cell volume. The likelihood of popping depended on cell-wall stress, and the separating cells split open asymmetrically, leaving the daughters connected by a hinge. An elastostatic model of the wall indicated high circumferential stress in the peripheral ring before popping. Last, we observed small perforations in the peripheral ring that are likely initial points of mechanical failure. Thus, the ultrafast daughter cell separation in S. aureus appears to be driven by accumulation of stress in the peripheral ring and exhibits hallmarks of mechanical crack propagation.
Department of Chemistry, Stanford University, Stanford, CA 94305, USA. Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA. Howard Hughes Medical Institute (HHMI), Stanford University School of Medicine, Stanford, CA 94305, USA.
Xiaoxue
X
Zhou
Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA. Howard Hughes Medical Institute (HHMI), Stanford University School of Medicine, Stanford, CA 94305, USA. Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
David K
DK
Halladin
Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA. Howard Hughes Medical Institute (HHMI), Stanford University School of Medicine, Stanford, CA 94305, USA. Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Enrique R
ER
Rojas
Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA. Howard Hughes Medical Institute (HHMI), Stanford University School of Medicine, Stanford, CA 94305, USA.
Elena F
EF
Koslover
Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Timothy K
TK
Lee
Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA. Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Kerwyn Casey
KC
Huang
Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA. Howard Hughes Medical Institute (HHMI), Stanford University School of Medicine, Stanford, CA 94305, USA. Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA. theriot@stanford.edu.
Julie A
JA
Theriot
D002473:Cell Wall / Q000502:physiology / Q000648:ultrastructure; D048749:Cytokinesis; D008855:Microscopy, Electron, Scanning; D018715:Microscopy, Video; D013211:Staphylococcus aureus / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D013314:Stress, Mechanical; D013997:Time Factors