Abstract
Seminal plasma immunoglobulins of normospermic fertile Indian buffalo bulls were investigated using rabbit antibuffalo immunoglobulin (polyvalent) serum, rabbit antibuffalo IgG and IgM serums, gel diffusion, and immunoelectrophoretic analysis. Immunoglobulin G was the predominant immunoglobulin in the seminal plasma of the buffalo. Strong antigenic cross reactions were observed between the seminal plasma IgG molecules of the buffalo and cattle, indicating the structural homology of seminal plasma IgG of these two species. These observations are in accordance with the close taxonomic and phylogenetic relationship between buffalo and cattle in the evolution of ruminant species.