ANTIGENIC RELATEDNESS BETWEEN 7 AVIAN MYCOPLASMA SPECIES AS REVEALED BY WESTERN-BLOT-ANALYSIS

Crossreactivities among seven avian mycoplasma species (Mycoplasma gal lisepticum, M. synoviae, M. meleagridis, M. iowae, M. anatis, M. galli narum, and M. iners) were examined using rabbit polyclonal antisera an d two monoclonal antibodies (MAbs) against M. pneumoniae: Myc-9 and My c-4. The major antigens and crossreacting antigens of the seven mycopl asma species were demonstrated by immunoblotting assay using homologou s and heterologous antisera. Two-way cross-reacting antigens of MS and MG, with apparent molecular weights of 44,000 and 36,000, were identi fied. Additionally, the 36,000 protein of MG was recognized by all of the heterologous antisera. A large number of cross-reactivities, which have been never investigated before, were shown between M. meleagridi s and M. synoviae, between M. meleagridis and M. gallinarum, between M . meleagridis and M. iners, and between M. gallinarum and M. iners. Al l of the cross-reactions existing between the majority of the above sp ecies were considerably reduced or eliminated by adsorbing the polyclo nal antisera with a pool of heterologous antigens. Two MAbs against a M. pneumoniae protein of a molecular weight of 150,000 were also able to recognize several avian mycoplasma epitopes, of which two common ep itopes with molecular weights of 44,000 and 42,000 were present in mos t of the seven mycoplasma species.