Conversion of positive to negative chemotaxis by Ca2+ ionophore treatment in plasmodium of Physarum polycephalum

Autor: Yasuo Mito, Hajime Satoh, Kenzo Kurihara, Yonosuke Kobatake, Tetsuo Ueda
Rok vydání: 1980
Předmět:
Zdroj: Biochimica et Biophysica Acta (BBA) - General Subjects. 633:436-443
ISSN: 0304-4165
DOI: 10.1016/0304-4165(80)90201-9
Popis: The plasmodium of Physarum polycephalum was treated with Ca 2+ ionophores A23187 or X-537A, and the effects on the chemotactic and contractile activities were studied by applying a double-chamber method and an optical method. 1. (1) At low Ca 2+ concentration, attractants (glucose, L -alanine, KH 2 PO 4 ) remained as attractants and induced a relaxation in the plasmodial strand. Increase in the external Ca 2+ level caused a contraction of the plasmodium with the same stimuli, and hence converted the attractants to repellents. 2. (2) This phenomenon was specific to Ca 2+ ; Mg 2+ , Sr 3+ or Ba 2+ showed no appreciable effects. 3. (3) Repellents (sucrose, KCl, Quinine) induced a contraction, which was not altered by the Ca 2+ ionophore treatment. 4. (4) Efflux of Ca 2+ , which was measured by chemiluminescence of aequorin, increased on glucose reception in the presence of ionophore.
Databáze: OpenAIRE