Gene fusion in vivo using transductional cointegrates

A method is described which allows the efficient construction of hybrids between homologous genes. The technique is based on the phenomenon of cointegrate transduction in which the homology between cloned sequences present on a bacteriophage lambda vector and a plasmid vector is exploited to allow the packaging of a plasmid-phage recombinant. The size of the cointegrate molecule can be far beyond the normal packaging limit of lambda and still allow the transduction of plasmid-borne drug-resistance markers. This method allows the exchange of the 5' and 3' ends of the participating genes as well as the exchange of sequences residing between the end-points of homology between the two genes. Hybrids of either type were constructed between a sea urchin and a Drosophila actin gene using the transductional cointegrate method in vivo. This approach does not require the use of specialized phage or plasmid vectors and can also be used to screen plasmid libraries with a bacteriophage lambda probe.