ANDROGENETIC RAINBOW-TROUT PRODUCED USING SPERM FROM TETRAPLOID MALES SHOW IMPROVED SURVIVAL

Androgenesis is a technique which involves the production of individual with all their chromosomes from the male parent. It can be useful in generating homozygous lines of fish and in the recovery of genotypes from cryopreserved sperm. However, the survival of androgenetic diploid fish is typically very low; this may be due to the homozygosity of these individuals or to the treatments (egg irradiation, suppression of first cleavage) used in generating them. In this study, we produced androgenetic diploid rainbow trout using (1) normal (haploid) sperm and suppression of the first cleavage, and (2) sperm from tetraploid males. Survival of the androgenetic diploids generated using sperm from tetraploid males was much better than that of androgenetic diploids produced using haploid sperm, suggesting that egg irradiation is not an overwhelming problem in androgenesis and that cleavage suppression treatments and/or homozygosity may be responsible for their poor viability. We also generated viable androgenetic diploids using cryopreserved sperm from tetraploid males; this technique may be useful for gene banking. © 1990.