Comparative Studies on S-Glycoproteins Purified from Different S-Genotypes in Self-Incompatible BRASSICA Species II....

Antisera were prepared by immunization of apparently purified S-glycoproteins; one from an S allele of Brassica campestris and two from S alleles of B. oleracea. Each antiserum was reactive not only with the homologous S-glycoprotein but also with the heterologous ones, i.e. with the S-glycoproteins of the other S alleles of the same locus. In double diffusion tests, a spur against the heterologous S-glycoproteins suggested heterogeneity of the glycoproteins. The heterogeneity appears to involve a component of the molecule in which the genotypic specificity of an S-glycoprotein resides, probably, for the recognition site. Some molecular components are common to all tested S-glycoproteins and in this respect are like the public antigens of the MHC locus of mammals. The common molecular components were recognized between the S-allele-specific glycoproteins within B. oleracea and also between them and those of B. campestris. No S-specific substances were detected in buffer soluble homogenates of style, ovary or anther. However, these homogenates contained substances that had structures similar to the corresponding common parts of the S-glycoproteins.