Intracellular rotation and the phototropic response of Phycomyces

D. S. Dennison, K. W. Foster

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


Experimental evidence indicates that during phototropism, Phycomyces sporangiophores use their own net rotation to convert an apparently spatial stimulus to a temporal one. Conversion to a continuous temporal stimulus insures that phototropism never adapts as long as the spatial asymmetry in illumination is maintained. If this temporal stimulus is circumvented by rotating the cell backwards so that there is no net rotation of some of the receptors relative to the light, the response can be reduced by two-thirds. The system thus adapts to the incident light, resulting in a reduced response. For the illumination of a transparent cell, this compensating rotation speed is 10 degrees/min counterclockwise and probably corresponds to the photoreceptor rotation in the most effective part of the growing zone. We infer that this region is in the upper portion of the growing zone and that the receptor system rotates integrally with that region of the cell.

Original languageEnglish (US)
Pages (from-to)103-123
Number of pages21
JournalBiophysical Journal
Issue number1
StatePublished - 1977

ASJC Scopus subject areas

  • Biophysics


Dive into the research topics of 'Intracellular rotation and the phototropic response of Phycomyces'. Together they form a unique fingerprint.

Cite this