A 3 kDa peptide is involved in the chemoattraction in vitro of the male Schistosoma mansoni to the female

In vitro experiments on adult Schistosoma mansoni worms have shown the existence of mutual attraction between males and females mediated by factor(s) released by both sexes. Males were attracted to female-released factor(s), which was found in <30 kDa fractions. A combination of bioassays, size fractionations, chromatographic and chemical and enzymatic treatments were used to identify female-released factor(s) that attracted males. Boiling reduced the attraction of males towards female incubate. Male-attractant factor(s) was not in the female vomitus, and TLC showed the absence of lipids and carbohydrates in the female incubate. Male-attractant factor(s) was found to be sensitive to proteases and to be hydrophilic in nature. Using RP-HPLC, a 3260 Da peptide released by S. mansoni adult females that plays a role in attracting the males was identified, purified and partially characterized. A partial amino acid sequence of that peptide was obtained using MALDI peptide-MS and MALDI-TOF/TOF.