Abstract
We induced homozygous clones of amago salmon by gynogenetic chromosome manipulation. Mitotic gynogenesis diploid (mitotic-G2N) as first generation was produced by suppression of the first cleavage of the eggs inseminated with UV-irradiated sperm of rainbow trout by hydrostatic pressure shock. The yield of apparently normal gynogenetic embryos was 2.26% when the eggs were shocked at 650kg/cm2 of hydrostatic pressure for 6min at 5 h 30min (approximately 68 h•°C in cumulative temperature) after insemination. Homozygous evidence of gynogenetic juveniles was demonstrated by the segregation of Idh-3 and Pgm-1 loci. Five homozygous inbred strains were produced from the eggs of homozygous gynogenetic females by retaining the second polarbody, while outbred controls were produced for each strain by crossing with males of other strains. The clonal proof of these strains was demonstrated by the immunological acceptance of operculum allografts from inbred sisters. Similar survivals were shown among clones produced by mothers from identical strain. On the other hand, various survivals were seen between the clones using maternal parents from different strains. These results suggested that the line selection was a vital factor in clone production.
