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 plant cell comprising a targeting vector, the targeting vector comprising in a 5′ to 3′ orientation:
(a) a first region of homology comprising sequences having homology to a region of interest in the plant cell genome;
(b) a first target site for a first zinc finger nuclease, wherein the first target site is not present in the plant cell genome;
(c) a first coding sequence encoding a 5′ piece of a first selectable marker gene, wherein the selectable marker gene is divided into two pieces, a 5′ piece and a 3′ piece, wherein the 3′ end of the 5′ piece and the 5′ end of the 3′ piece are partially duplicative of each other;
(d) a promoter operably linked to a second marker gene, wherein in between the promoter and the second marker gene is a second target site for a second zinc finger nuclease as described in part (e) that follows;
(e) a second target site for a second zinc finger nuclease, wherein the second target site for the second zinc finger nuclease is not present in the plant cell genome;
(f) the second selectable marker gene;
(g) a second coding sequence encoding the 3′ piece of the first selectable marker gene;
(h) the first target site; and
(i) a second region of homology having homology to a region of interest in the plant cell genome,
wherein the first marker gene is reconstituted upon cleavage of the second target site by the second zinc finger nuclease.
2. The plant cell of claim 1 , wherein the first selectable marker gene is selected from the group consisting of green fluorescent protein (GFP), P-glucuronidase (GUS), phosphinothricin N-acetyl transferase (PAT, BAR), neomycin phosphotransferase, P-lactamase, catechol dioxygenase, a-amylase, tyrosinase, P-galactosidase, luciferase, aequorin, EPSP synthase, nitrilase, acetolactate synthase (ALS), dihydrofolate reductase (DHFR), dalapon dehalogenase and anthranilate synthase.
3. The vector of claim 1 , wherein the second selectable marker gene is selected from the group consisting of green fluorescent protein (GFP), P-glucuronidase (GUS), phosphinothricin N-acetyl transferase (PAT, BAR), neomycin phosphotransferase, P-lactamase, catechol dioxygenase, a-amylase, tyrosinase, P-galactosidase, luciferase, aequorin, EPSP synthase, nitrilase, acetolactate synthase (ALS), dihydrofolate reductase (DHFR), dalapon dehalogenase and anthranilate synthase.
4. The plant cell of claim 1 , wherein the first and second target sites are mammalian gene sequences.
5. The plant cell of claim 1 , wherein the vector is integrated into the genome of the plant cell.