Abstract
The optimal conditions to induce androgenetic diploids using 60Co gamma irradiation and hydrostatic pressure shock in amago salmon Oncorhynchus masou ishikawae were determined. Androgenetic haploids were produced when eggs were irradiated prior to fertilization, with an optimal dose of 450 Gray. Diploid amago salmon were produced from irradiated eggs by suppression of the first cleavage after fertilization with normal sperm. The optimal timing of the hydrostatic pressure shock (650 kgf/cm2, 6min) was determined to be 7.5 hours after insemination at 10°C. DNA fingerprinting showed that the androgenetic offspring (second generation in androgenesis) were clones, thereby demonstrating that the androgenetic diploids (first generation in androgenesis) produced in these experiments were completely homozygous.
