Editorial: Structure, Function and Evolution of Complex Cellular Organization in Bacteria and Archaea

Multicellularity and cellular cooperation confer novel functions on organs following a structure–function relationship. How regulated cell migration, division and differentiation events generate cellular arrangements has been investigated, providing insight into the regulation of genetically encoded patterning processes. Much less is known about the higher-order properties of cellular organization within organs, and how their functional coordination through global spatial relations shape and constrain organ function. Key questions to be addressed include: why are cells organized in the way they are? What is the significance of the patterns of cellular organization selected for by evolution? What other configurations are possible? These may be addressed through a combination of global cellular interaction mapping and network science to uncover the relationship between organ structure and function. Using this approach, global cellular organization can be discretized and analysed, providing a quantitative framework to explore developmental processes. Each of the local and global properties of integrated multicellular systems can be analysed and compared across different tissues and models in discrete terms. Advances in high-resolution microscopy and image analysis continue to make cellular interaction mapping possible in an increasing variety of biological systems and tissues, broadening the further potential application of this approach. Understanding the higher-order properties of complex cellular assemblies provides the opportunity to explore the evolution and constraints of cell organization, establishing structure–function relationships that can guide future organ design.

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STRUCTURE-FUNCTION RELATIONSHIPS OF THE SINOATRIAL NODE

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127403008831 ◽

2003 ◽

Vol 13 (12) ◽

pp. 3621-3629 ◽

Cited By ~ 2

Author(s):

HALINA DOBRZYNSKI ◽

HENGGUI ZHANG ◽

SALLY E. WRIGHT ◽

ARUN V. HOLDEN ◽

MARK R. BOYETT

Keyword(s):

Mathematical Modeling ◽

Structure Function ◽

Sinoatrial Node ◽

Conduction Block ◽

Heterogeneous Structure ◽

Cellular Organization ◽

Gradient Model ◽

Atrial Muscle

The sinoatrial node, the pacemaker of the heart, is a structurally and functionally complex and heterogeneous structure. Histology, immunohistochemistry, electrophysiology and mathematical modeling of the sinoatrial node are reviewed to reveal the structure-function relationships of the sinoatrial node. It is argued that contact between the sinoatrial node and surrounding atrial muscle is limited to permit driving of the atrial muscle by the sinoatrial node but not suppression of the sinoatrial node by the atrial muscle (which is more hyperpolarized). It is argued that a protective conduction block zone on one side of the sinoatrial node is the result of a lack of myocytes. Finally, it is argued that the cellular organization of the sinoatrial node is best described by the gradient model.

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Structural aspects of osmoregulation in porphyra

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082923 ◽

1978 ◽

Vol 36 (2) ◽

pp. 412-413

Author(s):

C. Wiencke ◽

A. Lauchli

Keyword(s):

Culture Medium ◽

Point Of View ◽

Chemical Fixation ◽

Cellular Organization ◽

Osmotic Adaptation ◽

Osmotic Balance ◽

Activity Of Enzymes ◽

Osmotic Agents ◽

Vacuolar System ◽

Structural Aspects

Osmoregulatory mechanisms in algae were investigated mainly from a physiological point of view (KAUSS 1977, HELLEBUST 1976). In Porphyra two osmotic agents, i. e. floridoside/isofloridoside (KAUSS 1968) and certain ions, such as K+ and Na+(EPPLEY et al. 1960) are considered for osmotic balance. Accumulations of ions (particularly Na+) in the cytoplasm during osmotic adaptation is improbable, because the activity of enzymes is generally inhibited by high ionic concentrations (FLOWERS et al. 1977).The cellular organization of Porphyra was studied with special emphasis on the development of the vacuolar system under different hyperosmotic conditions. Porphyra was cultivated at various strengths of the culture medium ASP 12 (PROVASOLI 1961) ranging from normal to 6 times concentrated (6x) culture medium. Por electron microscopy freeze fracturing was used (specimens fixed in 2% glutaraldehyde and incubated in 30% glycerol, preparation in a BALZERS BA 360 M apparatus), because chemical fixation gave poor results.

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Three-dimensional image analysis and visualization in confocal light microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146631 ◽

1993 ◽

Vol 51 ◽

pp. 158-159

Author(s):

J. K. Samarabandu ◽

R. Acharya ◽

D. R. Pareddy ◽

P. C. Cheng

Keyword(s):

Depth Perception ◽

Computer Graphic ◽

Three Dimensional ◽

Cellular Organization ◽

Data Set ◽

Computational Burden ◽

Interactive Operation ◽

Cell Organization ◽

Confocal Images ◽

3D Digitization

In the study of cell organization in a maize meristem, direct viewing of confocal optical sections in 3D (by means of 3D projection of the volumetric data set, Figure 1) becomes very difficult and confusing because of the large number of nucleus involved. Numerical description of the cellular organization (e.g. position, size and orientation of each structure) and computer graphic presentation are some of the solutions to effectively study the structure of such a complex system. An attempt at data-reduction by means of manually contouring cell nucleus in 3D was reported (Summers et al., 1990). Apart from being labour intensive, this 3D digitization technique suffers from the inaccuracies of manual 3D tracing related to the depth perception of the operator. However, it does demonstrate that reducing stack of confocal images to a 3D graphic representation helps to visualize and analyze complex tissues (Figure 2). This procedure also significantly reduce computational burden in an interactive operation.

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