%0 Journal Article %A Thomas, Donovan D. %A Butler, Debra L. %T Cationic Interactions Regulate the Initiation and Termination of Zoospore Activity in the Water Mould Achlya heterosexualis %D 1989 %J Microbiology, %V 135 %N 7 %P 1917-1922 %@ 1465-2080 %R https://doi.org/10.1099/00221287-135-7-1917 %I Microbiology Society, %X The zoosporic phase of the water mould Achlya heterosexualis, initiated when zoospores emerge from cysts, is strongly influenced by cations. The concentrations of Ca2+ and K+ present in the medium can determine whether or not zoospores will be released from cysts, whether zoospore motion will be approximately linear or circular, rapid or slow, and when zoospore activity will be terminated by encystment. Ionic effects on zoospore motility are rapid and reversible over short time spans; within a 2 min period motility can be strongly suppressed by increasing the [K+] and then restored by increasing the [Ca2+]. Trifluoperazine, considered to be an anti-calmodulin drug, both inhibits zoospore release, and arrests zoospore motility. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-135-7-1917