Retrofitting BACs and PACs With LoxP Transposons to Generate Nested Deletions

Physical mapping of markers in large-insert bacterial artificial chromosome (BAC) and P1-derived artificial chromosome (PAC) clones requires efficient methods for obtaining position-specific sequence information along the insert DNA. Because substantial quantities of high-quality clone DNA can be easily prepared from BACs and PACs, they are also potentially valuable reagents for direct use in biologic experiments that seek to functionally evaluate the sequences contained in them. Thus, both physical and functional mapping objectives would be facilitated by an efficient strategy for making nested deletions from one end of the insert DNA in a BAC or PAC clone.