Zinc-finger nuclease-driven targeted integration into mammalian genomes using donors with limited chromosomal homology.
We previously demonstrated high-frequency, targeted DNA addition mediated by the homology-directed DNA repair pathway. This method uses a zinc-finger nuclease (ZFN) to create a site-specific double-strand break (DSB) that facilitates copying of genetic information into the chromosome from an exogenous donor molecule. Such donors typically contain two approximately 750 bp regions of chromosomal sequence required for homology-directed DNA repair. Here, we demonstrate that easily-generated linear donors with extremely short (50 bp) homology regions drive transgene integration into 5-10% of chromosomes. Moreover, we measure the overhangs produced by ZFN cleavage and find that oligonucleotide donors with single-stranded 5' overhangs complementary to those made by ZFNs are efficiently ligated in vivo to the DSB. Greater than 10% of all chromosomes directly incorporate this exogenous DNA via a process that is dependent upon and guided by complementary 5' overhangs on the donor DNA. Finally, we extend this non-homologous end-joining (NHEJ)-based technique by directly inserting donor DNA comprising recombinase sites into large deletions created by the simultaneous action of two separate ZFN pairs. Up to 50% of deletions contained a donor insertion. Targeted DNA addition via NHEJ complements our homology-directed targeted integration approaches, adding versatility to the manipulation of mammalian genomes.
Orlando
Salvatore J
SJ
Sangamo BioSciences, 501 Canal Bvld, Richmond, CA 94804, USA.
Santiago
Yolanda
Y
DeKelver
Russell C
RC
Freyvert
Yevgeniy
Y
Boydston
Elizabeth A
EA
Moehle
Erica A
EA
Choi
Vivian M
VM
Gopalan
Sunita M
SM
Lou
Jacqueline F
JF
Li
James
J
Miller
Jeffrey C
JC
Holmes
Michael C
MC
Gregory
Philip D
PD
Urnov
Fyodor D
FD
Cost
Gregory J
GJ
D000818:Animals; D016466:CHO Cells; D033481:Chromosomes, Mammalian / Q000737:chemistry; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000737:chemistry; D053903:DNA Breaks, Double-Stranded; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry / Q000378:metabolism*; D018390:Gene Targeting / Q000379:methods*; D016678:Genome; D006801:Humans; D020014:K562 Cells; D012689:Sequence Homology, Nucleic Acid; D016335:Zinc Fingers
D004247:DNA; C035042:endodeoxyribonuclease FokI; D015252:Deoxyribonucleases, Type II Site-Specific