Micro- and Macrorheology of Jellyfish Extracellular Matrix

Abstract

Mechanical properties of the extracellular matrix (ECM) play a key role in tissue organization and morphogenesis. Rheological properties of jellyfish ECM (mesoglea) were measured in vivo at the cellular scale by passive microrheology techniques: microbeads were injected in jellyfish ECM and their Brownian motion was recorded to determine the mechanical properties of the surrounding medium. Microrheology results were compared with macrorheological measurements performed with a shear rheometer on slices of jellyfish mesoglea. We found that the ECM behaved as a viscoelastic gel at the macroscopic scale and as a much softer and heterogeneous viscoelastic structure at the microscopic scale. The fibrous architecture of the mesoglea, as observed by differential interference contrast and scanning electron microscopy, was in accord with these scale-dependent mechanical properties. Furthermore, the evolution of the mechanical properties of the ECM during aging was investigated by measuring microrheological properties at different jellyfish sizes. We measured that the ECM in adult jellyfish was locally stiffer than in juvenile ones. We argue that this stiffening is a consequence of local aggregations of fibers occurring gradually during aging of the jellyfish mesoglea and is enhanced by repetitive muscular contractions of the jellyfish.

Self-repairing symmetry in jellyfish through mechanically driven reorganization

“…Over hours or days, the arms gradually move into the cut site, until symmetry is fully regained. The mesoglea is a viscoelastic material that produces an elastic response over short timescales but behaves like a viscous fluid over longer time periods (36,61,68,69). Therefore, the ephyrae behaves like an elastic object in responding to fast muscular compression, and we speculate that the viscous aspect of the mesoglea may then help relax the organism to a new state with the arms slightly repositioned into the cut site.…”

“…1E). Between the two cells layers is the mesoglea, a viscoelastic, jelly-like substance composed predominantly of fibrous proteins and water (36).…”

“…S6). The dimensions of the ephyrae were measured directly, and the elastic and tensile modulus of the body were obtained from previous biomechanic studies (36,61). Simulation of the model (Fig.…”

Distributions of lifetime and maximum size of abortive clathrin-coated pits

“…In such a situation, simple models that capture the global behavior of the complex phenomena are very useful. To this end, in a recent paper 17 , we developed a coarse-grained model of CCP formation to address questions related to the temporal heterogeneity observed in CCP assembly. A key step of our analysis was the mapping of CCP assembly dynamics onto a one-dimensional random walk.…”

Aurelia auritaInspired Artificial Mesoglea

“…It is well-known that rapid changes in property of mesoglea occur as a function of time after it has been detached from the real animal. Gambini et al's [10] introduction of jellyfish extracellular material and micro-structures of the collagen fiber network provides insight into the structure of natural mesoglea. Zhu et al [11] while studying the swelling properties and mechanical strength of natural mesoglea, developed an excellent method for SEM imaging of collagen network structures of the mesoglea.…”