Patent ID: 7919322

Claim:
A method for selectively deleting a region of a chromosome in a prokaryotic cell, the method comprising: a) providing to the prokaryotic cell a first nucleic acid encoding a first retargeted LI.LtrB intron and a first intron-encoded protein (IEP), wherein the first LI.LtrB intron and the first IEP sequences are under control of expression control sequences, wherein the first retargeted LI.LtrB intron comprises a first loxP site, and the first retargeted LI.LtrB intron inserts into a first targeted location in the chromosome; b) providing to the prokaryotic cell comprising the first nucleic acid, a second nucleic acid encoding a second retargeted LI.LtrB intron and a second IEP, wherein the LI.LtrB intron and the second IEP sequences are under control of expression control sequences, wherein the second retargeted LI.LtrB intron comprises a second loxP site, and the second retargeted LI.LtrB intron inserts into a second targeted location in the chromosome, wherein the first and the second loxP sites are in the same orientation; and c) providing to the prokaryotic cell comprising the first and the second nucleic acid a Cre recombinase that mediates recombination between the first and the second loxP sites to delete the region between the sites at the first and the second targeted locations in the chromosome of the prokaryotic cell.