Introduction and Expression of CAT Gene in Rainbow Trout.

Abstract

RSV-CAT (Chloramphenicol acetyltransferase gene linked to the long terminal repeat of Rous sarcoma virus) was microinjected into the cytoplasm of 1-cell stage rainbow trout eggs. Eggs were pretreated with reduced-glutathione to facilitate microinjection. The survival rates of microinjected eggs were 77\% at the eyed stage, 74\% at hatching, and 70\% at swimming-up; this did not differ from these of the control group. Seventy-day-old fish were cut along the symmetry axis. Right and left side tissues were utilized for DNA analysis and CAT assay respectively. In 6 individuals out of 10, RSV-CAT was integrated into the host genome and formed head-to-tail and tail-to-tail concatemers. Furthermore, acetylated chloramphenicol was detected in 9 individuals (including the above mentioned 6) out of 10. Therefore, these results suggest that in 6 out of 10 individuals RSV-CAT was expressed after integration into the host genome.