| 摘要 |
PROBLEM TO BE SOLVED: To provide a mutant lox P sequence that causes no recombination reaction with the wild type lox P sequence, but causes the recombination reac tion between same two mutant lox P sequences in the same level of efficiency as in the recombination reaction between two wild type lox P sequences in the presence of a recombinase Cre. SOLUTION: This mutant lox P sequence has the following properties: (a) In the wild type lox P sequence originating from E. coli P1 phase, at least one base selected from the second (T), the third (G), the fourth (T) or the fifth (A) among the eight bases at the middle (the spacer region) and at least one selected between the sixth (T) or the seventh (G) are substituted with different bases and the other regions than the spacer region may be substituted with arbitrary bases, (b) the mutant lox P sequence causes no recombination reaction with the wild type lox P sequence even in the presence of a recombinase, Cre, (c) but, it causes a specific recombination reaction with another mutant lox P sequence having the same sequence in the presence of a recombinase, Cre. By this mutant lox P sequence, gene introduction or gene substitution can be performed in high-class eukaryotic cells including mammalian cells in high efficiency. |
