Gene shuttling: moving of cloned DNA into and out of eukaryotic cells.

Successful shuttling of cloned DNA in eukaryotic cells should allow isolation of expressed genes. We tested the utility of cosmids for moving DNA into and out of eukaryotic cells. The unique cleavage of DNA at the cos site by the terminase function of lambda was exploited to maintain the linkage between the vector and inserted gene sequences, a prerequisite for successful rescue of the transforming DNA from high molecular weight DNA of the eukaryotic transformant. A cosmid recombinant containing the HSV thymidine kinase gene and a lambda recombinant containing the chicken thymidine kinase gene were used to test the feasability of this method. It was found that these recombinants can be rescued with high efficiency from DNA of HAT-resistant cells.