SEX-PHEROMONE COMMUNICATION IN BRACHIONUS-PLICATILIS (ROTIFERA)

1. 1. Sex pheromone communication plays an important role in regulating mating behavior of aquatic invertebrates but is poorly understood. A mate recognition bioassay using the rotifer Brachionus plicatilis is described that permits investigation of the molecular nature of chemical communication between females and males. 2. 2. The female signal molecule is a glycoprotein that can be removed by washing females with 10 mM CHAPS or 100 mM EDTA. Washing females with 100 mM sodium phosphate pH 8.0, 2 M NaCl or 100 mM Tris-HCl pH 9.5 had no effect on their ability to elicit male mating responses. 3. 3. Females treated with the glycosidase N-glycanase for 5 min elicited significantly fewer male copulations than untreated females. Males treated with N-glycanase for 10 min attempted significantly fewer copulations with females. 4. 4. Lectins were used to probe the biochemical features of the oligosaccharide portion of the MRG. Females were exposed to nine lectins and evaluated for their ability to elicit male mating responses. Five lectins did not block mate recognition, but females treated with Concanavalin A, Lens culinaris, Pisum sativum and Vicia faba lectins elicited male mating with a lower probability than control females. Males treated with these same five lectins had lower rates of copulation with untreated females. 5. 5. Dose-response experiments revealed that females treated with 112 μg/ml of Con A and 15 μg/ml of Lens elicited only 50% as many male mating attempts as control females. © 1990.