Linear expression elements: a rapid, in vivo, method to screen for gene functions

The increasing accumulation of genomic sequence information has accentuated the need for new methods to efficiently assess gene function and to prepar e reagents to study these functions. Toward solving this general problem in functional genomics, we report a method by which any PCR-amplified open-re ading frame (ORF) can be noncovalently linked to a eukaryotic promoter and terminator, and directly injected into animals to produce local gene expres sion. We also demonstrate that ORFs can be delivered into mice to produce a ntibodies specific for the encoded foreign protein by simply attaching mamm alian promoter and terminator sequences. This technology makes it possible to screen large numbers of genes rapidly for their functions in vivo or to produce immune responses without the necessity of cloning, bacterial propag ation, or protein purification.