TY - JOUR
T1 - Worms under pressure
T2 - Bulk mechanical properties of C. elegans are independent of the cuticle
AU - Gilpin, William
AU - Uppaluri, Sravanti
AU - Brangwynne, Clifford P.
N1 - Funding Information:
W.G. was supported in part by The Fred Fox Fellowship, The Princeton Class of 1984 Memorial Fund, The Princeton Class of 1955 Senior Thesis Fund, and the Princeton Class of 1930 Fellowship. Some strains were provided by the Caenorhabditis Genetics Center, which is funded by the National Institutes of Health Office of Research Infrastructure Programs (No. P40 OD010440). This work was also supported by the National Institutes of Health Director’s New Innovator Award (No. 1DP2GM105437-01), the Searle Scholars Program, and a National Science Foundation CAREER Award (No. 1253035).
Publisher Copyright:
© 2015 Biophysical Society.
PY - 2015/4/21
Y1 - 2015/4/21
N2 - The mechanical properties of cells and tissues play a well-known role in physiology and disease. The model organism Caenorhabditis elegans exhibits mechanical properties that are still poorly understood, but are thought to be dominated by its collagen-rich outer cuticle. To our knowledge, we use a novel microfluidic technique to reveal that the worm responds linearly to low applied hydrostatic stress, exhibiting a volumetric compression with a bulk modulus, κ = 140 ± 20 kPa; applying negative pressures leads to volumetric expansion of the worm, with a similar bulk modulus. Surprisingly, however, we find that a variety of collagen mutants and pharmacological perturbations targeting the cuticle do not impact the bulk modulus. Moreover, the worm exhibits dramatic stiffening at higher stresses - behavior that is also independent of the cuticle. The stress-strain curves for all conditions can be scaled onto a master equation, suggesting that C. elegans exhibits a universal elastic response dominated by the mechanics of pressurized internal organs.
AB - The mechanical properties of cells and tissues play a well-known role in physiology and disease. The model organism Caenorhabditis elegans exhibits mechanical properties that are still poorly understood, but are thought to be dominated by its collagen-rich outer cuticle. To our knowledge, we use a novel microfluidic technique to reveal that the worm responds linearly to low applied hydrostatic stress, exhibiting a volumetric compression with a bulk modulus, κ = 140 ± 20 kPa; applying negative pressures leads to volumetric expansion of the worm, with a similar bulk modulus. Surprisingly, however, we find that a variety of collagen mutants and pharmacological perturbations targeting the cuticle do not impact the bulk modulus. Moreover, the worm exhibits dramatic stiffening at higher stresses - behavior that is also independent of the cuticle. The stress-strain curves for all conditions can be scaled onto a master equation, suggesting that C. elegans exhibits a universal elastic response dominated by the mechanics of pressurized internal organs.
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U2 - 10.1016/j.bpj.2015.03.020
DO - 10.1016/j.bpj.2015.03.020
M3 - Article
C2 - 25902429
AN - SCOPUS:84928255100
SN - 0006-3495
VL - 108
SP - 1887
EP - 1898
JO - Biophysical Journal
JF - Biophysical Journal
IS - 8
ER -