Limits...
Emergent mechanics of biological structures.

Dumont S, Prakash M - Mol. Biol. Cell (2014)

Bottom Line: Unlike the engineered macroscopic structures that we commonly build, biological structures are dynamic and self-organize: they sculpt themselves and change their own architecture, and they have structural building blocks that generate force and constantly come on and off.A description of such structures defies current traditional mechanical frameworks.It requires approaches that account for active force-generating parts and for the formation of spatial and temporal patterns utilizing a diverse array of building blocks.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Tissue Biology and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143-0512 sophie.dumont@ucsf.edu.

Show MeSH
Macromolecular structures and cellular ensembles show conceptual similarities in how forces flow through them, although at different length scales. (A) The spindle is one example of a macromolecular structure with changing force propagation paths (Elting, Hueschen, et al., 2014; Sikirzhytski, Magidson, et al., 2014). Dynamic restructuring of these paths under internal and external perturbations is crucial to the robustness of chromosome segregation. (B) Similarly, an ensemble of cells under internal and external forces deforms and restructures itself, rerouting forces (see line path thickness) passing through individual cells. Owing to the dynamic nature of cell–cell interactions, cellular ensembles can show surprising behaviors: they can flow like a fluid and yet sustain forces like a solid.
© Copyright Policy - creative-commons
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4230603&req=5

Figure 2: Macromolecular structures and cellular ensembles show conceptual similarities in how forces flow through them, although at different length scales. (A) The spindle is one example of a macromolecular structure with changing force propagation paths (Elting, Hueschen, et al., 2014; Sikirzhytski, Magidson, et al., 2014). Dynamic restructuring of these paths under internal and external perturbations is crucial to the robustness of chromosome segregation. (B) Similarly, an ensemble of cells under internal and external forces deforms and restructures itself, rerouting forces (see line path thickness) passing through individual cells. Owing to the dynamic nature of cell–cell interactions, cellular ensembles can show surprising behaviors: they can flow like a fluid and yet sustain forces like a solid.

Mentions: Moving to a larger length scale, that of multicellular organisms, how can we comprehend the physical properties of a large cluster of homogeneous or heterogeneous cells? From the outset, calling an aggregate of cells or a tissue “dynamic” may seem paradoxical. After all, our common macroscopic perception of a tissue is static and fixed—a structure that resists stress and maintains the mechanical integrity of organs. However, at the microscopic scale of individual cells, a very different (and dynamic) story emerges, as is readily seen during development and tissue maintenance and homeostasis (Guillot and Lecuit, 2013). From the early proposals of differential adhesion theory, cellular ensembles have been described as being like a fluid with specific surface tension associated with cellular interfaces (Foty and Steinberg, 2005). For decades, we have known that macroscopic cellular rearrangements play a critical role in morphogenesis at developmental time scales. Mature tissue has also been uncovered to have the plasticity to recover from injury and trauma and to maintain homeostasis, for example, in the kidney (Rabelink and Little, 2013). Thus the conceptual challenges described above for understanding the mechanics of macromolecular assemblies are similar at multicellular scales (Figure 2).


Emergent mechanics of biological structures.

Dumont S, Prakash M - Mol. Biol. Cell (2014)

Macromolecular structures and cellular ensembles show conceptual similarities in how forces flow through them, although at different length scales. (A) The spindle is one example of a macromolecular structure with changing force propagation paths (Elting, Hueschen, et al., 2014; Sikirzhytski, Magidson, et al., 2014). Dynamic restructuring of these paths under internal and external perturbations is crucial to the robustness of chromosome segregation. (B) Similarly, an ensemble of cells under internal and external forces deforms and restructures itself, rerouting forces (see line path thickness) passing through individual cells. Owing to the dynamic nature of cell–cell interactions, cellular ensembles can show surprising behaviors: they can flow like a fluid and yet sustain forces like a solid.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4230603&req=5

Figure 2: Macromolecular structures and cellular ensembles show conceptual similarities in how forces flow through them, although at different length scales. (A) The spindle is one example of a macromolecular structure with changing force propagation paths (Elting, Hueschen, et al., 2014; Sikirzhytski, Magidson, et al., 2014). Dynamic restructuring of these paths under internal and external perturbations is crucial to the robustness of chromosome segregation. (B) Similarly, an ensemble of cells under internal and external forces deforms and restructures itself, rerouting forces (see line path thickness) passing through individual cells. Owing to the dynamic nature of cell–cell interactions, cellular ensembles can show surprising behaviors: they can flow like a fluid and yet sustain forces like a solid.
Mentions: Moving to a larger length scale, that of multicellular organisms, how can we comprehend the physical properties of a large cluster of homogeneous or heterogeneous cells? From the outset, calling an aggregate of cells or a tissue “dynamic” may seem paradoxical. After all, our common macroscopic perception of a tissue is static and fixed—a structure that resists stress and maintains the mechanical integrity of organs. However, at the microscopic scale of individual cells, a very different (and dynamic) story emerges, as is readily seen during development and tissue maintenance and homeostasis (Guillot and Lecuit, 2013). From the early proposals of differential adhesion theory, cellular ensembles have been described as being like a fluid with specific surface tension associated with cellular interfaces (Foty and Steinberg, 2005). For decades, we have known that macroscopic cellular rearrangements play a critical role in morphogenesis at developmental time scales. Mature tissue has also been uncovered to have the plasticity to recover from injury and trauma and to maintain homeostasis, for example, in the kidney (Rabelink and Little, 2013). Thus the conceptual challenges described above for understanding the mechanics of macromolecular assemblies are similar at multicellular scales (Figure 2).

Bottom Line: Unlike the engineered macroscopic structures that we commonly build, biological structures are dynamic and self-organize: they sculpt themselves and change their own architecture, and they have structural building blocks that generate force and constantly come on and off.A description of such structures defies current traditional mechanical frameworks.It requires approaches that account for active force-generating parts and for the formation of spatial and temporal patterns utilizing a diverse array of building blocks.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Tissue Biology and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143-0512 sophie.dumont@ucsf.edu.

Show MeSH