Metabolism of radioactive antheridiol by Achlya species

Antheridiol is a hormone produced by the water mold Achlya that induces the formation of male sex organs and the productionof oogoniol a second hormone that induces the formation of female sex organs. The fate of radioactive antheridiol in liquid cultures of heterothallic males and females of A. ambisexualis and A. bisexualis and the homothallics A. americana and A. conspicua was studied. After a lag period of 30–80 min many strains rapidly converted antheridiol to metabolite A. After a lag of 60 min a few strains converted metabolite A to metabolite B. The metabolites were at least a hundred times less active than antheridiol. From their R_f values they did not appear to be oogoniol. Cycloheximide and actinomycin D added before antheridiol or during the lag period prevented the formation of the metabolites except in the homothallic A. americana which already possessed the enzyme for the formation of metabolite A. Strains that readily acted as males were induced by antheridiol to metabolise antheridiol. Strong females were not induced by the antheriodiol concentrations used. It is suggested that metabolism of antheridiol could amplify the chemotropic stimulus for the male sex organs to grow up a gradient of antheridiol to the female organs.