Carbohydrate/lectin interactions between the nematophagous fungus,Arthrobotrys oligospora, and the infective juveniles ofTrichostrongylus colubriformis(Nematoda)

SUMMARYRemoval of the sheath of the ensheathed infective juvenile ofTrichostrongylus colubriformisprevents capture by the nematophagous fungusArthrobotrys oligospora. Exposure of the trap hyphae to a variety of saccharides, which may block a recognition system based on lectin/carbohydrate binding, failed to prevent capture but some saccharides did inhibit penetration and invasion by the fungus. Capture and penetration thus appear to be two distinct processes with capture being less specific than penetration. Carbohydrate residues were absent from the outer surface of the cuticle and the sheath but were present on the inner surface of the sheath. The limited accessibility of these lectin-binding sites may explain the slow process of infection of the infective juvenile by the fungus. The sheath does not protect the infective juvenile against attack by this nematophagous fungus.