Depolymerization-driven flow in nematode spermatozoa relates crawling speed to size and shape

Mark Zajac, Brian Dacanay, William A. Mohler, Charles William Wolgemuth

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Cell crawling is an inherently physical process that includes protrusion of the leading edge, adhesion to the substrate, and advance of the trailing cell body. Research into advance of the cell body has focused on actomyosin contraction, with cytoskeletal disassembly regarded as incidental, rather than causative; however, extracts from nematode spermatozoa, which use Major Sperm Protein rather than actin, provide at least one example where cytoskeletal disassembly apparently generates force in the absence of molecular motors. To test whether depolymerization can explain force production during nematode sperm crawling, we constructed a mathematical model that simultaneously describes the dynamics of both the cytoskeleton and the cytosol. We also performed corresponding experiments using motile Caenorhabditis elegans spermatozoa. Our experiments reveal that crawling speed is an increasing function of both cell size and anterior-posterior elongation. The quantitative,depolymerization-driven model robustly predicts that cell speed should increase with cell size and yields a cytoskeletal disassembly rate that is consistent with previous measurements. Notably, the model requires anisotropic elasticity, with the cell being stiffer along the direction of motion, to accurately reproduce the dependence of speed on elongation. Our simulations also predict that speed should increase with cytoskeletal anisotropy and disassembly rate.

Original languageEnglish (US)
Pages (from-to)3810-3823
Number of pages14
JournalBiophysical Journal
Volume94
Issue number10
DOIs
StatePublished - May 15 2008
Externally publishedYes

Fingerprint

Spermatozoa
Cell Size
Physical Phenomena
Actomyosin
Anisotropy
Elasticity
Caenorhabditis elegans
Cytoskeleton
Cytosol
Actins
Theoretical Models
Research
Proteins
Cell Body

ASJC Scopus subject areas

  • Biophysics

Cite this

Depolymerization-driven flow in nematode spermatozoa relates crawling speed to size and shape. / Zajac, Mark; Dacanay, Brian; Mohler, William A.; Wolgemuth, Charles William.

In: Biophysical Journal, Vol. 94, No. 10, 15.05.2008, p. 3810-3823.

Research output: Contribution to journalArticle

Zajac, Mark ; Dacanay, Brian ; Mohler, William A. ; Wolgemuth, Charles William. / Depolymerization-driven flow in nematode spermatozoa relates crawling speed to size and shape. In: Biophysical Journal. 2008 ; Vol. 94, No. 10. pp. 3810-3823.
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