Effects of Antheridiol on Growth, Branching and Electrical Currents of Hyphae of Achlya ambisexualis

SUMMARY: Treatment of male hyphae of the water mould Achlya ambisexualis with the female sex pheromone, antheridiol, caused them to stop extending. This response was accompanied by a marked decline in the characteristic inward current just behind the hyphal apex. After a hypha had stopped, a site of inward current developed some way behind the apex. Then an antheridial branch developed at this site. These responses only occurred in the absence of nutrients; in the presence of nutrients the hyphal extension rate and current pattern were unaffected by the addition of antheridiol.