Genomewide unbiased identification of DSBs evaluated by sequencing (GUIDE-Seq)
Unbiased, genomewide and highly sensitive methods for detecting mutations, e.g., off-target mutations, induced by engineered nucleases.
1. A method for tagging double-stranded break(s) (DSB(s)) in the genomic DNA (gDNA) of living cell(s), the method comprising:
contacting the cell(s) with a blunt-ended and 5′ phosphorylated double-stranded oligodeoxynucleotide (dsODN), wherein (a) phosphorothioate linkages are present on both 3′ ends, or (b) phosphorothioate linkages are present on both 3′ ends and both 5′ ends; and
expressing or activating an engineered nuclease in the cell(s) under conditions sufficient for the nuclease to induce DSBs in the gDNA of the cell, and for the cell to repair the DSBs, integrating a dsODN at one or more DSBs, thereby producing tagged gDNA comprising an integrated dsODN.
2. The method of claim 1 , further comprising:
amplifying a portion of the tagged gDNA comprising an integrated dsODN.
3. The method of claim 2 , wherein amplifying a portion of the gDNA comprises:
fragmenting the tagged gDNA, thereby producing fragmented gDNA;
ligating ends of the fragmented gDNA with a universal adapter, thereby producing ligated DNA; and performing polymerase chain reaction (PCR) on the ligated DNA.
4. The method of claim 1 , wherein the cell is a mammalian cell.
5. The method of claim 1 , wherein the dsODN is 30-35 nts long.
6. The method of claim 1 , wherein the dsODN is 15-50 nts long.
7. The method of claim 1 , wherein phosphorothioate linkages are present on both 3′ ends, but not on the 5′ ends of the dsODN.
8. The method of claim 1 , wherein the dsODN contains a randomized DNA barcode.
9. The method of claim 1 , further comprising:
shearing the tagged gDNA into fragments; and
preparing the fragments for sequencing by end-repair, a-tailing, and ligation of a single-tailed sequencing adapter.
10. The method of claim 1 , wherein phosphorothioate linkages are present on both 3′ ends and both 5′ ends.
11. The method of claim 1 , wherein the engineered nuclease is selected from the group consisting of meganucleases, zinc-finger nucleases, transcription activator effector-like nucleases (TALEN), and Clustered Regularly Interspaced Short Palindromic Repeast (CRISPR)/Cas RNA-guided nucleases (CRISPR/Cas RGNs).
12. The method of claim 11 , wherein the engineered nuclease is a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas RNA guided nuclease.
13. The method of claim 1 , wherein the cell is a human cell.
14. The method of claim 1 , wherein the cell is a cultured cell.
15. The method of claim 1 , wherein the dsODN is 20-40 nt long.
16. The method of claim 1 , wherein the dsODN comprises a PCR primer binding site on each strand.