THE BACTERIOPHAGE-T7 BINARY-SYSTEM ACTIVATES TRANSIENT TRANSGENE EXPRESSION IN ZEBRAFISH (DANIO-RERIO) EMBRYOS

The bacteriophage T7 binary expression system is widely used in vitro for high level selective expression of cloned genes but its applicatio n to in vivo models has not yet been investigated. In the present work , we show that coinjection into fertilized zebrafish eggs of pE1T7R, a n expression plasmid bearing the T7 RNA polymerase gene driven by the cytomegalovirus (CMV) promoter, together with reporter vectors contain ing the Escherichia coil lacZ gene driven by the T7 promoter, resulted in the efficient expression of the reporter gene in 24-h mosaic trans genic embryos. Conversely, embryos receiving an unrelated CMV-expressi on plasmid, instead of pE1T7R, lacked significant reporter gene activi ty, indicating the strict requirement of T7 polymerase to activate the T7 promoter in these embryos. The present study demonstrates the poss ibility of applying efficiently the bacteriophage T7 binary system in vivo to a vertebrate model. (C) 1997 Academic Press.