Zinc finger nuclease-mediated homologous recombination
Disclosed herein are methods and compositions for targeted integration of an exogenous sequence into a predetermined target site in a plant genome.
1. A method for introducing an exogenous sequence into the chromosomal DNA of a plant cell, the method comprising the steps of:
(a) contacting the cell with a donor DNA vector comprising an exogenous sequence encoding a protein, the exogenous sequence flanked by first and second sequences identical or homologous and non-identical to the chromosomal DNA of the plant cell; and
(b) transforming the cell with one or more polynucleotides encoding first and second zinc finger nucleases in the cell, each zinc finger nuclease comprising a 3-, 4-, 5- or 6-finger zinc finger domain that binds to a target site in the chromosomal DNA and a cleavage domain and further wherein the first and second zinc finger nucleases dimerize to cleave the chromosomal DNA between and at a location from 0.1 to 3 kilobase pairs from the edges of the chromosomal DNA sequences having homology to the first and/or second sequences;
such that cleavage of chromosomal DNA in step (b) stimulates incorporation of the exogenous DNA sequence into the genome by homologous recombination of the first and second sequences and chromosomal DNA.
2. The method of claim 1 , wherein the cleavage domain comprises the cleavage domain of a Type IIS restriction endonuclease.
3. The method of claim 1 , wherein the polynucleotides encoding the first and second zinc finger nucleases are stably integrated into the genome of the plant cell.
4. The method of claim 1 , wherein the protein is a selectable marker.
5. The method of claim 4 , wherein the selectable marker is selected from the group consisting of green fluorescent protein (GFP), β-glucuronidase (GUS), phosphinothricin N-acetyl transferase (PAT, BAR), neomycin phosphotransferase, β-lactamase, catechol dioxygenase, α-amylase, tyrosinase, β-galactosidase, luciferase, aequorin, EPSP synthase, nitrilase, acetolactate synthase (ALS), dihydrofolate reductase (DHFR), dalapon dehalogenase and anthranilate synthase.
6. The method of claim 1 , wherein the exogenous sequence further comprises one or more regulatory sequences.