Details

Autor(en) / Beteiligte

• Gross, J.D
• Peacey, M.J
• Trevan, D.J

Titel

Signal emission and signal propagation during early aggregation in Dictyostelium discoideum

Ist Teil von

• Journal of cell science, 1976-12, Vol.22 (3), p.645-656

Ort / Verlag

England

Erscheinungsjahr

1976

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Waves of chemotactic movement during the early phase of aggregation in Dictyostelium discoideum are of 2 kinds, concentric waves produced by cells that emit cyclic AMP signals spontaneously, and spirals generated by excitations relayed continuously around loops of excitable cells. The period of a spiral wave is the time taken for the excitation to make one complete circuit of the pacemaker loop. We have compared signal emission from the 2 types of source in time-lapse films made at a variety of temperatures. Our results show that spiral waves have a characteristic period length throughout most if not all of the early phase of aggregation, and that the period of concentric waves is generally longer and more variable. Temperature has a pronounced effect on period length and a lesser effect on propagation velocity. We find that each individual wave is propagated at constant velocity over distances of 1-2 cm but that the velocity of successive waves declines. This decline probably reflects some cumulative effect of the chemotactic excitations on the excitable properties of the aggregating cells.