Schistosoma mansoni: changes in the rate of tyrosine uptake by unisexual females after stimulation by males and male extracts.

The rate of uptake of H3 tyrosine by unisexual females in vitro was accelerated by 22% when male worm extract was added to the culture medium. Pairing of unisexual females with mature male worms in vitro resulted in a similar acceleration of H3 tyrosine uptake. As tyrosine is avidly taken up by the vitelline gland for the formation of egg shell protein the change in the rate of H3 tyrosine uptake can be employed as a sensitive quantitative criterion for assessing its development following stimulation.