Progress in plasmodial differentiation improves regularity of oscillating contractions in Physarum polycephalum
Article first published online: 2 JAN 2013
© The Author(s) Journal compilation © 2007 International Federation for Cell Biology
Cell Biology International
Volume 31, Issue 1, pages 11–15, January 2007
How to Cite
Helf, M. and Achenbach, F. (2007), Progress in plasmodial differentiation improves regularity of oscillating contractions in Physarum polycephalum. Cell Biology International, 31: 11–15. doi: 10.1016/j.cellbi.2006.08.005
- Issue published online: 2 JAN 2013
- Article first published online: 2 JAN 2013
- Received 17 June 2006, revised 11 July 2006, accepted 7 August 2006
- Non-muscle actomyosin;
- Oscillating contractions
Based on the knowledge about subcellular morphogenetic processes in the acellular slime mold Physarum polycephalum, we hypothesized that during differentiation of undifferentiated endoplasm to the highly differentiated complex structure of the contractile apparatus of this organism, the regularity of oscillating contractions must improve.
We measured the endogenous contraction automaticity starting from the de novo generation within minutes after sampling small portions of undifferentiated endoplasm.
The standard deviation of the normalized period duration of these samples was compared to the respective values of radial contractions of differentiated protoplasmic plasmodial strands. The mean normalized standard deviation in endoplasmic drops was 28.3 ± 12.2%. Respective values in protoplasmic strands were 10.0 ± 3.7%. The difference between the experimental groups was highly significant (p < 0.0001).
We interpret the verification of our hypothesis as an indication that the very regular oscillating contractions in fully differentiated stages of Physarum require the complex structure of the sophisticated contractile apparatus, represented by the circular plasmalemma invagination system of protoplasmic strands, while the regularity is lower in stages, where the differentiation is still in progress. We believe that this is due to deficits in coordination capabilities, which need a directional and spatially oriented protoplasmic streaming as a precondition.