Development of Long-Term Cell Lines from Homozygous Clones of Rainbow Trout

The objective of this work was to develop syngeneic embryonic cell lines from several homozygous clones of rainbow trout Oncorhynchus mykiss, which had been previously derived by androgenesis, a chromosome manipulation technique. The nine embryonic cell lines were cultured in RPMI-1640 with 10% fetal bovine serum. Seven of the lines exhibited epithelial morphology, and the remaining two were fibroblast-like cell lines. Modal diploid chromosome numbers of each of the lines ranged from 58 to 71, which is near the known chromosome number for rainbow trout (2n = 58–64). Chromosome counts obtained from the leukocytes of the parental fish indicated that 2 parental lines (OSU 142 and Hot Creek 71) were composed of 60 chromosomes, whereas the third parental line (Arlee 12) was composed of 64 chromosomes. Restriction fragment length polymorphisms revealed that the patterns associated with DNA from the cell lines resembled that of the parents. Infectious hematopoietic necrosis virus replicated in all of the cell lines. These cell lines and the homozygous clones of rainbow trout from which they were derived should have future application in salmonid immunology and disease research.