Monoclonal antibodies to the soya bean cyst nematode, Heterodera glycines

In order to identify proteinaceous secretions involved in feeding of the soya bean cyst nematode, Heterodera glycines, over 1800 monoclonal antibodies (MAbs) were raised in four experiments using extracts of second stage juveniles and adult females as the immunogens. A rapid, indirect immunofluorescent screening procedure is described that enabled the antigens for 100 MAbs/day to be localised in juveniles. A similar immunofluorescent screening procedure for adult females was less successful due to the masking of the fluorophore by autofluorescence; additional approaches, including enzyme linked immunosorbent assays (ELISA), were necessary to aid in the screening process. The immunosuppressive drug, cyclophosphamide, had an effect on the range of antibodies obtained in two experiments. One was designed to favour antibodies specific to the hatched rather than the unhatched juvenile, whereas the second aimed to select those for the anterior rather than the posterior part of the adult female. A large number of MAbs showed well defined specificities and numbers are given in parentheses for those that recognised the following potential sites of secretion into the plant: the subventral pharyngeal glands (84), the dorsal pharyngeal gland (5), the amphidial pouches (10) and the excretory system (15). These MAbs will aid further work to define the role of nematode secretions in host invasion and the feeding process of this cyst nematode.