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Biophoton Conference September 2000
Deleayed Luminescence of Acetabularia. New perspectives.
Roeland Van Wijk Ph.D., Rafael Gaya Moreno
International Institute of Biophysics, Neuss, Germany,
and Department of Molecular Cell Biology, Utrecht University, The Netherlands
Introduction
Spontaneous luminescence and light-induced delayed luminescence of living organisms are assumed to contain information on the quality of the living state of these organisms. In the last years many biological systems have shown this close connection between the biological state of the system and physical parameters of biophoton emission. Sofar, our experimental results deal with several biological systems:
Hypothesis
The examples point to a general underlying phenomenon, namely that delayed luminescence reflects the state of the living organism and that a change in delayed luminescence reflects a change in the living state. In fact, we can hypothesize that a transition from one state to the other, like during differentiation, might be reflected in a change in the characteristics of delayed luminescence. In order to test this hypothesis it is necessary to develop a biological model that enables the quantification of a simple differentiation and also enables spontaneous and delayed luminescence during this transition. The giant unicellular Acetabularia acetabulans is used as a model for this study of the relationship between biophoton emission and spatio-temporal pattern formations in a single cell.
Cell Growth, differentiation and coherent cytoplasmic domains.
The single Acetabularia cell shows a characteristic pattern of differentiations, including the repetitive formation of whorls of hairs during the growth of the stalk-like cell and finally the formation of a reproductive cap. In recent studies these regular developmental transitions of cell growth and whorl formation have been quantified in detail.
The intracellular motility and patterns of streaming during growth and differentiation is characterized by video-microscopy, in particular the formation and dynamic activity of cytoplasmic domains. The domains are characterized by their coherent properties in tension and compression. The underlying perturbation of the cytoskeleton can be presented by a model of percolation transition. Perturbation of any part of such a tensegrity network has a dynamic consequence throughout its domain but also results in the to transient character of these domains. The latter is probably due to the transient interconnections in the cytoskeleton during the tension and compression of the domains.. Sofar, the investigations have focussed on the parameters for the description of the transient and coherent character of these domains (Van Wijk et al, manuscript in preparation).
Experiments on delayed luminescence
The basic correlation between the cytoplasmic motility and biophoton emission has been established by Van Wijk, Musumeci and colleagues (1999). They used the inhaled anaesthetic chloroform. Incubating Acetabularia cells in chloroform significantly and rapidly affect both organelle motility and delayed luminescence. These observations have been repeated by Van Wijk and Van Aken using halothane, another inhaled anaesthetic.
The results suggested that delayed luminescence is related to the integrity of the dynamic cytoplasmic organization. In order to increase the repeatebility of the luminescence measurements of Acetabularia cells a special system for handling Acetabularia cells was developed. This system allowed highly reliable measurements for periods of even days. Using this system a further careful study was performed on the effects of on delayed luminescence of the inhaled anaesthetics chloroform, isoflurane and sevoflurane.
Characterization of delayed luminescence
The characterization of the delayed luminescence requires parameters that sufficiently describe the decay curve. The emission curve is dependent on intensity, duration and wavelength of excitation. In fact, the delayed emission curves showed hyperbolic relaxation, under some conditions even oscillatory relaxation. It has been demonstrated that external conditions of excitation as well as the inhibition of internal processes cause a change in the capacity for oscillatory relaxation in cells. These experimental findings are now quantitated according to the model of Popp (Popp, 2000). He investigated the the physical and biological characteristics of biophotons, and has traced back the biophoton emission to coherent states of the biophoton field.
Present state
The state-of-art is that series of measurements of induced and spontaneous luminescence
are carried out during a single well defined cycle of growth and differentiation and under the appropriate physical conditions for excitation. The result of this series is important for understanding the role of domain coherency in growth and differentiation (Van Wijk, 2000).
References
R. Van Wijk, D.H.J. Schamhart. Regulatory aspects of low intensity photon emission . Experientia 44 (1988) 586-593.
R. Van Wijk, J. Van Aken. Light-induced photon emission by rat hepatocytes and hepatoma cells. Cell Biophysics 18 (1991) 15-20.
R. Van Wijk, J. Van Aken. Spontaneous and light-induced photon emission by rat hepatocytes and by hepatoma cells. In: Recent Advances in Biophoton Research and its Application, Eds. Popp, Li and Gu (World Scientific, Singapore. 1992a) pp. 207-229.
R. Van Wijk, J. Van Aken. Photon emission in tumor biology. Experientia 48 (1992b) 1092-1102.
R. Van Wijk, H. Van Aken, W. Mei, F.A. Popp. Light-induced photon emission by mammalian cells. J. Photochem. Photobiol. (1993) 75-79.
R. Van Wijk, J.M. Van Aken, J.E.M. Souren. Ultraweak delayed photon emission and light scattering of different mammalian cell types. In: Biophotonics, Eds. Beloussov and Popp (Bioinform Service Co, Moscow, 1995( pp. 221-232.
R. Van Wijk, J.M. Van Aken, H.E. Laerdal, J.E.M. Souren. Relaxation dynamics of light-induced photon emission by mammalian cells and nuclei. In: Current Developments of Biophysics, Eds. Zhang, Popp and Bischof (Hangzhou University Press, Hangzhou, 1996) pp. 126-141.
R. Van Wijk, J.M. Van Aken, J.E.M. Souren. An evaluation of delayed luminescence of mammalian cells. Trends in Photochem. Photobiol. 4 (1997) 87-97.
R. Van Wijk, A.Scordino, A. Triglia, F. Musumeci. Simultaneous measurements of delayed luminescence and chloroplast organization in Acetabularia acetabulum. J. Photochem. Photobiol. 49 (1999) 142-149.
J.E.M. Souren, E. Boon-Niermeyer and R. Van Wijk. Germination capacity of tomato seeds and ultra-weak photon-induced delayed luminesce. In: Biophotonics and Coherent Systems, Eds. Beloussov, Popp, Voeikov and Van Wijk (Moscow University Press 2000) pp. 419-430.
R. Van Wijk. Tote Molekule und lebende Zelle. In: Elemente des Lebens, Eds. Duerr, Popp and Schommers (SFG Fachverlag, Kusterdingen 2000) pp.155-177.
