EENdb - Utilities  >  Genome modification methods
Summary of genome modification methods induced by EENs
MethodFull NameDescriptionComments
NHEJ Non-Homologous End-Joining
(small indels)
When the DSBs (double strand breaks) caused by EENs are repaired in the cells via the error-prone NHEJ, small indels (insertions/deletions) and mutations may be introduced in the target site. This is the most frequently used genome modification strategy induced by EENs, though the outcome is un-controllable/un-predictable.
NHEJ (DisDel) Non-Homologous End-Joining
(Distal Deletion)
Two pairs of EENs with target sites at the same chromosome may induce a distal chromosomal deletion between the two DSBs. More than one gene could be disrupted simultaneously by this method.
NHEJ (ODC) Non-Homologous End-Joining
(Oligonucleotide Duplex Capture)
A short double-strand oligonucleotide with overhangs complementary to those generated by EENs (predicted to be a 4-bp 5'-overhang for ZFNs in most cases) may be captured and inserted into the DSB of DNA. To use this method, the precise situation of the DSBs induced by EENs needs to be characterized.
NHEJ (others) Non-Homologous End-Joining
(other types)
Chromosomal inversion, translocation, etc. caused by DSBs.
HR Homologous Recombination
(disruption, addition, correction, replacement, knock-in, etc.)
A homologous DNA template/donor is used to replace a homologous region of the original genomic DNA by HR (also called HDR, Homology-Directed/Dependent Repair/Recombination); the HR efficiency can be increased by DSB. Various precise genome modifications could be achieved by this method, though the efficiency of HR is relatively low.
HR (DisDel) Homologous Recombination
(Distal Deletion)
Use a DNA template/donor with one homologous arm nearby the EEN target site and the other distal homologous arm to may delete a large region of the chromosome.
More than one gene could be disrupted simultaneously by this method, though the efficiency of HR is relatively low.



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