Biology Reference
In-Depth Information
Systems Biomechanics of the Cell
Introduction
Systems biology is a branch of biological sciences on the frontier of today's inquiry
into the mechanisms of life. It studies nonintuitive effects of interaction of multiple
elements in biological systems, aiming to complement the study of the composition
of living matter (molecules, species, etc.) and to bring the mathematical methods
capable of describing complex processes to bear on biological problems. The early
work in systems biology, which originated in its modern form in the 1960s, was
remarkably diverse (reviewed in Maly
2009
). In comparison, most of the recent
effort has been motivated by the data explosion in descriptive genomics and pro-
teomics and devoted to the regulation of transcription and metabolism (see, e.g.,
Longabaugh and Bolouri
2006
; Orth et al.
2010
). These well-developed research
directions address the system-level problems in the
chemistry
of the living matter.
The
mechanics
, on the other hand, has so far attracted far less interest among sys-
tems biologists. It is the mechanics, however, that is responsible for the most obvi-
ous characteristics of the living matter—for the generation of its complex form and
movement. As any microscopist can attest, the complex (at the same time “whimsi-
cal” and “purposeful”) form and movement of living matter become unmistakable
already on the level of single cells. Biomechanics of the cell therefore appears to be
a worthy application for the systems method. This short monograph presents a per-
sonal view on the most elementary systems-biomechanical effects that arise on the
cellular level of biological organization, and on how they can be analyzed with
adequate quantitative rigor.
Structurally and mechanically, in the generic eukaryotic cell it is useful to distin-
guish between the cell boundary and the cell body (Harold
2001
; Baluska et al.
2004
). The cell boundary appears invariably to be comprised of the actin cortex
underlying the plasma membrane; extraplasmatic material of varying mechanical
strength is common, which in plants and fungi may take the form of a rigid cell wall.
The cell body, properly so defined, is included inside the boundary and is comprised
of the nucleus and the juxtanuclear complex of microtubules and membranous
