ANDROGENETIC DIPLOIDS OF RAINBOW-TROUT (ONCORHYNCHUS-MYKISS) PRODUCED BY FUSED SPERM

Androgenesis is a technique that produces individuals with all of their chromosomes from male parents. It can be useful in generating homozygous lines of fish, and in the recovery of species from cryopreserved sperm. We produced androgenetic diploids by using fused sperm to fertilize eggs. Eggs of albino ''Yellow'' rainbow trout (Oncorhynchus mykiss) were exposed to Co-60 gamma-ray irradiation to inactivate the maternally-derived nuclear DNA, and were then fertilized with wild-type rainbow trout sperm fused using an artificial seminal plasma containing 85 mM CaCl2. Embryos that reached the hatching stage (average 0.11%) were pigmented. The nuclear DNA content of cells from newly hatched fry was the same as the DNA content of erythrocyte nuclei of normal diploids.