Deterministic Non-linear Dynamics in Phycomyces Sporangiophores

✍ Scribed by Peter A. Ensminger; Michael Vinson

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 366 KB
• Volume: 170
• Category: Article
• ISSN: 0022-5193
• DOI: 10.1006/jtbi.1994.1186

✦ Synopsis

The growth rate of the Phycomyces sporangiophore fluctuates under constant environmental conditions. To test for deterministic non-linearity in these growth-rate fluctuations, we applied variants of several recently developed techniques. We found that wild-type sporangiophores have a significant non-linear component, whereas non-linear contributions to the growth fluctuations of a stiff ((\operatorname{mad} \mathrm{E})) mutant are less significant. This difference may be caused by the dominance of a linear 10.4 min rhythm in the mutant's growth rate. Previous system analysis studies, which involved stimulation by dynamically changing light intensity, identified a non-linearity near the input of the Phycomyces sensory system. Our results, which involve analysis of growth-rate fluctuations under constant environmental conditions, demonstrate the presence of deterministic non-linearity even in the absence of sensory stimulation.