There is actually a surprisingly large overlap between two systems. Both CRISPR and AAV can be used for targeted integrations (by using site specific homologous regions to direct the HDR machinery). AAV can also be used for a random integrations and expression from long-term episomes.
The major differences between the methods are some of the more practical aspects rather than the actual repair mechanism; things like delivery methods, necessary components, penetrance in in vivo systems, etc.
Delivery/components: CRISPR requires the transfection or injection of multiple components (Cas Proteins, sgRNAs, tracrRNA depending on the organism, homologous repair templates, etc). AAV requires transfection of a multi-component virus which encodes all necessary machinery. Additionally CRISPR generally requires introduction into either a germ or progenitor cells so that the edit can be spread throughout the entire organism, or into a subset of cells (which is easy to do when they are in culture but nearly impossible to do in a living organism (yet!)). AAV is much easier to target a particular subset of cells to make edits (such as specifically transfecting lung tissue or organ; see gene therapy methods for treating cystic fibrosis in lung tissue).
Penetrance: See above. If either methods are used to edit germ cells, then the edits will be organism wide in the mature adult (ideally). On the flip side, mosaicism is nearly always unavoidable using CRISPR when targeting somatic cells in a living organism. There are some exceptions (see CarT therapy) where certain cell populations can be removed from the body, edited and returned. However for most cell populations there is no feasible way to edit them specifically and efficiently. There is also a chance of mosaic integrations with AAV but without examining particular cases it is difficult to say what the percentages would be.
Overall: CRISPR and AAV are comparable when editing germ cells. AAV methods are much better when targeting somatic cells in a living system such a patient require gene therapy. Hope this helps. Source: Post-doctoral researchers who utilizes CRIPSR frequently in my own research (specifically in the nematode C. elegans), and has dabbled in AAV methods in cell culture.
Linking AAV article for more specifics:
"The Role of Recombinant AAV in Precise Genome Editing"
doi: 10.3389/fgeed.2021.799722
PMID: 35098210
Old_school_dreamer t1_jc2oowf wrote
Reply to CRISPR vs AAV - how do they differ? by HueX1
There is actually a surprisingly large overlap between two systems. Both CRISPR and AAV can be used for targeted integrations (by using site specific homologous regions to direct the HDR machinery). AAV can also be used for a random integrations and expression from long-term episomes.
The major differences between the methods are some of the more practical aspects rather than the actual repair mechanism; things like delivery methods, necessary components, penetrance in in vivo systems, etc.
Delivery/components: CRISPR requires the transfection or injection of multiple components (Cas Proteins, sgRNAs, tracrRNA depending on the organism, homologous repair templates, etc). AAV requires transfection of a multi-component virus which encodes all necessary machinery. Additionally CRISPR generally requires introduction into either a germ or progenitor cells so that the edit can be spread throughout the entire organism, or into a subset of cells (which is easy to do when they are in culture but nearly impossible to do in a living organism (yet!)). AAV is much easier to target a particular subset of cells to make edits (such as specifically transfecting lung tissue or organ; see gene therapy methods for treating cystic fibrosis in lung tissue).
Penetrance: See above. If either methods are used to edit germ cells, then the edits will be organism wide in the mature adult (ideally). On the flip side, mosaicism is nearly always unavoidable using CRISPR when targeting somatic cells in a living organism. There are some exceptions (see CarT therapy) where certain cell populations can be removed from the body, edited and returned. However for most cell populations there is no feasible way to edit them specifically and efficiently. There is also a chance of mosaic integrations with AAV but without examining particular cases it is difficult to say what the percentages would be.
Overall: CRISPR and AAV are comparable when editing germ cells. AAV methods are much better when targeting somatic cells in a living system such a patient require gene therapy. Hope this helps. Source: Post-doctoral researchers who utilizes CRIPSR frequently in my own research (specifically in the nematode C. elegans), and has dabbled in AAV methods in cell culture.
Linking AAV article for more specifics:
"The Role of Recombinant AAV in Precise Genome Editing" doi: 10.3389/fgeed.2021.799722 PMID: 35098210