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Planta

, Volume 150, Issue 2, pp 180–188 | Cite as

Synchronization and signal transmission in protoplasmic strands ofPhysarum

Reaction to varying temperature gradients
  • U. Achenbach
  • K. E. Wohlfarth-Bottermann
Article

Abstract

Isolated protoplasmic strands ofPhysarum polycephalum, mounted as a trapeze, show synchronous contraction activities when the isometric tension development of both arms of the trapeze is measured independently of each other. This phase regulation can be experimentally disturbed by temperature changes. Within a permanent gradient, however, the phases become resynchronized. The maximal temperature gradient between both arms allowing a phase resynchronization was approximately 9° C along a distance of 25 mm. The transmission of the signal along the middle piece of the trapeze (which, as the connecting part of both arms, is responsible for signal transmission in phase synchronization) can be influenced by temperature changes. The minimal temperature allowing a signal transmission is 15° C, the maximal temperature approximately 29° C. A morphological investigation of protoplasmic strands mounted as trapezes revealed that the normal architecture of the objects is not influenced by the experimental trapeze arrangement. Permanent thermal gradients induce thermotactic reactions, i.e., a preferred protoplasmic mass transport into one arm of the trapeze. This leads, after several hours, to a morphological asymmetry of the trapeze. In spite of the fact that this reaction limits the temporal use of trapezes within thermal gradients to 2–3 h, the capacity of such strands for phase regulation is not hindered. Thermal gradients are suitable methods for studying the unknown phase-regulating factor and its transmission. As criteria for an intact pathway of signal transmission, the capacity of the trapeze arms to resynchronize as well as to maintain synchronization within a thermal gradient can be used.

Key words

Biological oscillators Oscillations (PhysarumPhase synchronization Physarum Temperature gradients 

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References

  1. Achenbach, U., Wohlfarth-Bottermann, K.E. (1980) Oscillating contractions in protoplasmic strands ofPhysarum: Mechanical and thermal methods of phase shifting for studying the nature of the synchronizing factor and its transmission. J. Exp. Biol.85, 21–31Google Scholar
  2. Cieslawska, M., Grebecki, A. (1978) Contraction-expansion rhythms simultaneously observed in two sites ofPhysarum polycephalum plasmodium. Acta Protozool.17, 533–541Google Scholar
  3. Fleischer, M., Wohlfarth-Bottermann, K.E. (1975) Correlation between tension force generation, fibrillogenesis and ultrastructure of cytoplasmic actomyosin during isometric and isotonic contractions of protoplasmic strands. Cytobiologie10, 339–365Google Scholar
  4. Grebecki, A., Cieslawska, M. (1978) Plasmodium ofPhysarum polycephalum as a synchronous contractile system. Cytobiologie17, 335–342Google Scholar
  5. Grebecki, A., Moczon, M. (1978) Correlation of contractile activity and of streaming direction between branching veins ofPhysarum polycephalum plasmodium. Protoplasma97, 153–164Google Scholar
  6. Hejnowicz, Z., Wohlfarth-Bottermann, K.E. (1980) Propagated waves induced by gradients of physiological factors within plasmodia ofPhysarum polycephalum. Planta150, 144–152Google Scholar
  7. Hülsmann, N., Wohlfarth-Bottermann, K.E. (1978a) Spatio-temporal relationships between protoplasmic streaming and contraction activities in plasmodial veins ofPhysarum polycephalum. Cytobiologie17, 317–334Google Scholar
  8. Hülsmann, N., Wohlfarth-Bottermann, K.E. (1978b) Räumliche und zeitliche Analyse von kontraktionsabhängigen Oberflächenbewegungen beiPhysarum polycephalum. Cytobiologie17, 23–41Google Scholar
  9. Kamiya, N. (1959) Protoplasmic streaming. Protoplasmatologia VIII, 3a. Springer, WienGoogle Scholar
  10. Krüger, J., Wohlfarth-Bottermann, K.E. (1978) Oscillating contractions in protoplasmic strands ofPhysarum. Stretch induced phase shifts and their synchronization. J. Interdiscip. Cycle Res.9, 61–71Google Scholar
  11. Moczon, M., Grebecki, A. (1978) Time relationships between the longitudinal and radial contraction in plasmodial veins ofPhysarum polycephalum. Acta Protozoologica17, 543–550Google Scholar
  12. Parducz, B. (1952) Eine neue Schnellfixierungsmethode im Dienste der Protistenforschung und des Unterrichts. Ann. Mus. Nat. Hung.2, 5–15Google Scholar
  13. Takeuchi, Y., Yoneda, M. (1977) Synchrony in the rhythm of the contraction-relaxation cycle in two plasmodial strands ofPhysarum polycephalum. J. Cell Sci.26, 151–160Google Scholar
  14. Tso, W.W., Mansour, T.E. (1975) Thermotaxis in a slime mold,Physarum polycephalum. J. Behav. Biol.14, 499–504Google Scholar
  15. Wohlfarth-Bottermann, K.E. (1974) Plasmalemma invaginations as characteristic constituents of plasmodia ofPhysarum polycephalum. J. Cell Sci.16, 23–37Google Scholar
  16. Wohlfarth-Bottermann, K.E. (1975) Tensiometric demonstration of endogenous oscillating contractions in plasmodia ofPhysarum polycephalum. Z. Pflanzenphysiol.76, 14–27Google Scholar
  17. Wohlfarth-Bottermann, K.E. (1975) Weitreichende fibrilläre Protoplasmadifferenzierungen und ihre Bedeutung für die Protoplasmaströmung. X. Die Anordnung der Actomyosinfibrillen in experimentell unbeeinflußten Protoplasma-Adern vonPhysarum in situ. Protistologica11, 19–30Google Scholar
  18. Wohlfarth-Bottermann, K.E. (1977) Oscillating contractions in protoplasmic strands ofPhysarum: Simultaneous tensiometry of longitudinal and radial rhythms, periodicity analysis and temperature dependence. J. Exp. Biol.67, 49–59Google Scholar
  19. Wohlfarth-Bottermann, K.E. (1979) Oscillatory contraction activity inPhysarum. J. Exp. Biol.81, 15–32Google Scholar
  20. Yoshimoto, Y., Kamiya, N. (1978a) Studies on contraction rhythm of the plasmodial strand. I. Synchronization of local rhythms. Protoplasma95, 89–99Google Scholar
  21. Yoshimoto, Y., Kamiya, N. (1978b) Studies on contraction rhythm of the plasmodial strand. III. Role of endoplasmic streaming in synchronization of local rhythms. Protoplasma95, 111–121Google Scholar

Copyright information

© Springer-Verlag 1980

Authors and Affiliations

  • U. Achenbach
    • 1
  • K. E. Wohlfarth-Bottermann
    • 1
  1. 1.Institut für CytologieUniversität BonnBonn 1Federal Republik of Germany

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