NEXT GENERATION GENOME EDITING TECHNOLOGIES Next-Generation-Genome-Editing-Technologies | Page 13

Smaller in size i.e. 40nt
100nt hybrid of trRNA and
24bp small
crRNA
Synthesis is cheaper
Costly
Cheaper. Can be ordered as
oligonucleotide
AT rich regions can be AT rich regions cannot be Has lower potential for off-
targeted targeted as they lack PAM target effects
sites
Benefits:
ƒ ƒ Does not require PAM sequence, so choosing a target is more flexible than in CAS9.
ƒ ƒ Uses DNA guides instead of RNA guides, which are short 24bp DNA.
ƒ ƒ Editing efficiency is not affected as transcription isn’t there, so changes in gRNA secondary
structure is not possible.
ƒ ƒ Small capacity viral vectors can be used.
ƒ ƒ Follows the concept of base removal i.e. randomly removing 1-20 nucleotides from cleavage
site given by gDNA. Therefore, foreign DNA cannot recover its original sequence.