MONOCLONAL-ANTIBODIES AS PROBES FOR FUNGAL WALL STRUCTURE DURING MORPHOGENESIS

Three monoclonal antibodies (mAbs), S4D1, S3B3 and S1E5, were produced from hybridoma cell lines raised from mice immunized with hyphal wall s of Neurospora crassa and one (Pax-1) from mice immunized with hyphal walls of Paxillus involutus. In immunofluorescence studies, the three IV. crassa mAbs recognized epitopes with different patterns of distri bution at the hyphal surface of IV. crassa. S4D1 recognized an epitope which was present on the surface of both conidia and hyphae; S3B3 rec ognized an epitope seen only at the ends of conidia or in the septal r egion of hyphae and conidial chains; and S1E5 recognized an epitope pr esent on the surface of hyphae, but not on mature conidia. mAb Pax-1 r eacted with hyphal wall fragments of Pan involutus and with N. crassa conidia in a similar way to S3B3. S4D1 reacted with an epitope found i n 1,3-alpha-glucan preparations from hyphal walls of different fungi. The surface distribution of this epitope varied: it was found on the s urface of both conidia and hyphae of N. crassa and Aspergillus nidulan s, on the basidiospore surface only of Amanita muscaria, and on the hy phae but not the conidia of Penicillium chrysogenum. Immunogold studie s revealed that the epitope was present throughout the wall of conidia and hyphae of N. crassa. mAbs S3B3, S1E5 and Pax-1 also reacted with other fungi: for example Pax-1 cross-reacted with all fungi tested exc ept for a member of the Zygomycota. Immunogold studies revealed that e pitopes of these three mAbs were present within the inner layers of th e walls of conidia and hyphae of IV. crassa.