PRODUCTION OF ANDROGENETIC DIPLOIDS IN AMAGO SALMON ONCORHYNCHUS-MASOU ISHIKAWAE

The optimal conditions to induce androgenetic diploids using Co-60 gam ma irradiation and hydrostatic pressure shock in amago salmon Oncorhyn chus masou ishikawae were determined. Androgenetic haploids were produ ced when eggs were irradiated prior to fertilization, with an optimal dose of 450 Gray. Diploid amago salmon were produced from irradiated e ggs by suppression of the first cleavage after fertilization with norm al sperm. The optimal timing of the hydrostatic pressure shock (650 kg f/cm(2), 6 min) was determined to be 7.5 hours after insemination at 1 0 degrees C. DNA fingerprinting showed that the androgenetic offspring (second generation in androgenesis) were clones, thereby demonstratin g that the androgenetic diploids (first generation in androgenesis) pr oduced in these experiments were completely homozygous.