1991 Volume 57 Issue 8 Pages 1511-1517
Reporter genes, whose products are easily detectable, are useful to analyze activities of pro-moters in transgenic animals. We report the utilization of bacterial β-galactosidase gene as a re-porter of foreign gene expression in rainbow trout embryos and fry using a hisochemical detection method. We microinjected the plasmid pmiwZ containing β-galactosidase gene fused to an avian chimeric promoter, miw into fertilized eggs of rainbow trout obtained by inseminating unfertilized eggs from a female trout matured under the controlled photoperiod with cryopreserved milt and treated with glutathione. The promoter miw consists of Rous sarcoma virus (RSV) long terminal repeat (LTR) and chicken β-actin promoter and its activity in trout was shown by transient chloram-phenicol acetyltransferase (CAT) assay on a trout cell line, before microinjection. The expression of pmiwZ in embryos and fry was detected histochemically 7 and 30 days after fertilization. In 7-day-old embryos, the introduced sequence was expressed mosaically in embryonic body and rarely in the cells out of the embryonic body. In the fry at 30 days after fertilization, the expression was tissue-specifically detected in the yolk sac. Thus, β-galactosidase reporter and its histochemical de-tection method fuctioned well in trout embryos and fry.
