Intracellular Centrifugal Separation of Organelles in Phycomyces

Intracellular Centrifugal Separation of Organelles In

Live sporangiophores of Phycomyces blakesleeanus were centrifuged at 35,000 rpm . The cell contents sedimented into distinct layers, and each layer was studied with an electron microscope and with cytochemical methods . The following layers were found (their volumes and their densities are shown in Fig . 3) : 1 . polyphosphates ; 2 . polyphosphates and protein crystals ; 3 . glycogen ; 4 . yell...

Tropic Responses of Phycomyces Sporangiophores to Gravitational and Centrifugal Stimuli

A low-speed centrifuge was used to study the tropic responses of Phycomyces sporangiophores in darkness to the stimulus of combined gravitational and centrifugal forces. If this stimulus is constant the response is a relatively slow tropic reaction, which persists for up to 12 hours. The response is accelerated by increasing the magnitude of the gravitational-centrifugal force. A wholly differe...

Modeling Spatial Distribution of Intracellular Organelles by Molecular Motors

Interaction between gravitropism and phototropism in sporangiophores of Phycomyces blakesleeanus.

The interaction between gravitropism and phototropism was analyzed for sporangiophores of Phycomyces blakesleeanus. Fluence rate-response curves for phototropism were generated under three different conditions: (a) for stationary sporangiophores, which reached photogravitropic equilibrium; (b) for sporangiophores, which were clinostated head-over during phototropic stimulation; and (c) for spor...

Intracellular recordings from phycomyces.

Intracellular recordings from the giant sporangiophore of Phycomyces stage II were obtained. The mean transmembrane potential for 30 observations was -119.9 millivolts (negative inside), and it did not change either as a result of a light stimulus or during dark adaptation. Injected depolarizing and hyperpolarizing step currents and steady currents did not produce any avidence of spike activity...