Targeted chromosomal mutagenesis using zinc finger nucleases
The present invention provides for a method or methods of targeted genetic recombination or mutagenesis in a host cell or organism, and compositions useful for carrying out the method. The targeting method of the present invention exploits endogenous cellular mechanisms for homologous recombination and repair of double stranded breaks in genetic material. The present invention provides numerous improvements over previous mutagenesis methods, such advantages include that the method is generally applicable to a wide variety of organisms, the method is targeted so that the disadvantages associated with random insertion of DNA into host genetic material are eliminated, and certain embodiments require relatively little manipulation of the host genetic material for success. Additionally, it provides a method that produces organisms with specific gene modifications in a short period of time.
1. A method of targeted genetic recombination in host cell comprising:
introducing into a host cell a nucleic acid molecule encoding a Zinc Finger Nuclease (ZFN) targeted to a chosen host chromosomal target locus;
inducing expression of the ZFN within the host cell; and
identifying a host cell in which the chosen host chromosomal target locus exhibits a mutation.
2. The method of claim 1 , wherein the mutation is a deletion of genetic material.
3. The method of claim 1 , wherein the mutation is an insertion of genetic material.
4. The method of claim 1 , wherein the mutation is both a deletion and an insertion of genetic material.
5. The method of claim 1 , further comprising introducing donor DNA into the host cell.
6. The method of claim 5 , wherein the donor DNA provides a gene sequence that encodes a product to be produced in the host cell.
7. The method of claim 6 , wherein the donor DNA provides a gene sequence that encodes a product selected from the group consisting of pharmaceuticals, hormones, proteins, nutriceuticals or chemicals.
8. The method of claim 1 , wherein the method further comprises:
selecting a zinc finger DNA binding domain capable of preferentially binding to a specific host target locus to be mutated;
selecting a nucleic acid encoding a non-specific DNA cleavage domain capable of cleaving double-stranded DNA when operatively linked to said binding domain and introduced into the host cell;
selecting an inducible control element capable of inducing expression in the host cell;
operatively linking the selected nucleic acid encoding the zinc finger the DNA binding domain and the selected nucleic acid encoding the cleavage domain and the inducible control element to produce a DNA construct;
introducing said DNA construct into a target host cell; and
identifying at least one host cell exhibiting recombination at the target locus in the host DNA.
9. The method of claim 8 , further comprising introducing donor DNA into the host cell.
10. The method of claim 9 , wherein the donor DNA provides a gene sequence that encodes a product to be produced in the host cell.
11. The method of claim 10 , wherein the donor DNA provides a gene sequence that encodes a product selected from the group consisting of pharmaceuticals, hormones, proteins, nutriceuticals or chemicals.
12. The method of claim 8 , wherein the DNA binding domain is comprised of three zinc fingers.
13. The method of claim 8 , wherein the zinc fingers DNA binding domain is a Cis2His2 zinc finger.
14. The method of claim 8 , wherein the cleavage domain is from a Type II restriction endonuclease.
15. The method of claim 14 , wherein the Type II restriction endonuclease is FokI.
16. The method of claim 8 , wherein the inducible control element is a heat-shock inducible control element.
17. The method of claim 9 , wherein the DNA construct further comprises DNA encoding one or more selectable markers.
18. The method of claim 17 , wherein the one or more selectable markers provides positive selection for cells expressing the one or more selectable markers.
19. The method of claim 17 , wherein the one or more selectable markers provides negative selection for cells expressing the one or more selectable markers.
20. The method of claim 17 , wherein the one or more selectable markers provides positive and negative selection for cells expressing the one or more selectable markers.
21. The method of claim 8 , wherein the one host cell exhibiting recombination is a somatic cell of the organism.
22. The method of claim 9 , wherein the DNA binding domain is comprised of three zinc fingers.
23. The method of claim 9 , wherein the cleavage domain is a Type II restriction endonuclease.
24. The method of claim 9 , wherein the inducible control element is a heat-shock inducible control element.