The antigenicity of bull seminal ribonuclease (AS RNase) appears to depend on the species of the recipient.
Partly purified AS RNase formed haemagglutination and precipitation antibodies in rabbits against the original antigen and also against pancreatic RNase A. Absorption of these antisera by pancreatic RNase A demonstrated that the antisera to the seminal RNase were still present in the sera. Rabbit antibodies to bovine pancreatic RNase A reacted with its homologous antigen and AS RNase.
Antibodies did not prevent the action of AS RNase in vivo. Antigenantibody complexes injected (i) into the testes of adult mice caused degeneration, (ii) into pregnant mice caused embryonic mortality, and (iii) into 6-day-old mice resulted in death.
Production of antibodies to AS RNase in mice also caused testicular damage, embryonic death and degeneration of Crocker tumour cells. Egg production in hens was reduced by similar treatment.