Immunoassay Comparison of Haplosporidan Spores from Teredo navalis and Haplosporidium nelsoni Spores from Crassostrea virginica

Abstract

ABSTRACTSpores of a haplosporidan infecting Teredo navalis Linnaeus have been described as morphologically indistinguishable from spores of Haplosporidium nelsoni. To test the hypothesis that these organisms are conspecific, a colloidal gold immunoassay was used to compare antigenic characteristics of the spores from both hosts. Rabbit antibody to formalin‐fixed spores from T. navalis was tested against paraffin sections of Crassostrea virginica infected with spores of H. nelsoni and against paraffin sections of infected 7″. navalis. Application of primary antibody was followed by addition of affinity purified goat anti‐rabbit IgG coaled on 5‐nm colloidal gold particles. The reaction was enhanced by precipitation of metallic silver; a positive reaction appeared as a dark brown to black signal at the site of each antigen‐antibody complex. Haplosporidium nelsoni spores did not react when assayed with the antibody made to spores from T. navalis. Spores from infected T. navalis tissue reacted positively with rabbit antibody. This result indicates that the spores from the 2 hosts are antigenicaliy distinct and suggests that they are different species.