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

Androgenesis is a technique that produces individuals with all of thei r chromosomes from male parents. It can be useful in generating homozy gous lines of fish, and in the recovery of species from cryopreserved sperm. We produced androgenetic diploids by using fused sperm to ferti lize eggs. Eggs of albino ''Yellow'' rainbow trout (Oncorhynchus mykis s) were exposed to Co-60 gamma-ray irradiation to inactivate the mater nally-derived nuclear DNA, and were then fertilized with wild-type rai nbow trout sperm fused using an artificial seminal plasma containing 8 5 mM CaCl2. Embryos that reached the hatching stage (average 0.11%) we re pigmented. The nuclear DNA content of cells from newly hatched fry was the same as the DNA content of erythrocyte nuclei of normal diploi ds.