Nippostrongylus brasiliensis: Female incubation,release of pheromone,fractionation of incubates

The release of pheromone by female Nippostrongylus brasiliensis as a crude incubate was linear for the first 2 hr, but declined after this period. Pheromone release in solution increased with temperature elevations until a 37 C incubation temperature was reached. Higher temperatures of incubation apparently caused diminished pheromone release. Gel filtration of female pheromone that was prepared as a crude incubate revealed biologically active elutions at K_av, 0.64 and 1.0. The timed release of female pheromone activity at these two elution regions coincided additively with the production of activity as a crude incubate. Each individual Chromatographic fraction from females accounted for about 50% of the pheromone activity of the crude, nonfractionated incubate, based on the male's bioassay response. Recombination of the K_av 0.64 and 1.0 elutions enabled recovery of pheromone activity that was similar to crude incubate. The gel filtration elution of 260-nm absorbance from male- or female-produced incubate was qualitatively similar, but a range of quantitative differences were evident. The fractionation of incubate from several female densities revealed only quantitative differences.