| 摘要 |
<p>Methods and compositions for transforming cells, resulting in efficient and stable site-specific integration of transgenes, are disclosed. Transformation is achieved by providing an acceptor DNA containing two inverted lox sequences and a donor DNA containing the same two inverted lox sequences, and then contacting the acceptor and donor DNA with a recombinase (e.g., Cre or Flp) which causes recombination at the lox sequences contained in the DNAs. Prior to recombination, the acceptor DNA is preferably integrated into the genome of a cell, such as an embryonic stem cell or a fertilized egg. The acceptor DNA optionally may further contain a negatively selectable marker to allow for screening of cells which have undergone the desired site-specific recombination (e.g., DNA cassette exchange).</p> |
