Schistosoma mansoni: adult worm chemoattraction with barriers of specific molecular weight exclusions.

Chemoattraction studies were done with Schistosoma mansoni adults from mice. To test for attraction or repulsion, some worm pairs were separated mechanically and the individuals placed in polycarbonate chambers. Experiments were done at 37 C and chambers contained dialysis tube chimneys. In all cases, heterosexual attraction occurred when one worm, but not two worms, were placed in the chimneys. Unperforated chimneys with specific molecular weight (Mr) exclusions were compared with perforated chimneys to study heterosexual attraction. Attraction was similar in designs using perforated chimneys and those with 50,000 and 12,000 Mr exclusions, but none was seen in chimney designs with 1000 Mr exclusions.