Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
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Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#2Pre-publication press release. Full text of article not available. How good was their control group? The press release says they used mice that had previously been edited with CRISPR/Cas9 and found off-target mutations, most of which were single nucleotides. Did they have a good control group so as to exclude random point mutations? Who knows? What is the theory on how CRISPR/Cas9 causes single nucleotide off-target mutations? No idea.
This is academic publishing at its absolute worst. Put out a sensational press release and whip up a fervour before the article is available. Those diving into the scrum to comment have not read the article.
Also, it's research by MDs. Just sayin'.
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#3Pre-publication press release. Full text of article not available. How good was their control group? The press release says they used mice that had previously been edited with CRISPR/Cas9 and found off-target mutations, most of which were single nucleotides. Did they have a good control group so as to exclude random point mutations? Who knows? What is the theory on how CRISPR/Cas9 causes single nucleotide off-target…
The article is available: https://www.nature.com/nmeth/journal/v14/n6/full/nmeth.4293....
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#4Off target effects from CRISPR is not new. The method leverages DNA repair mechanisms in the cell to do the recombination. All errors involved in those DNA repair mechanisms (there are distinct ones) would apply here。
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#5Off target effects from CRISPR is not new. The method leverages DNA repair mechanisms in the cell to do the recombination. All errors involved in those DNA repair mechanisms (there are distinct ones) would apply here。
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#6I seem to recall that in prior HN stories about CRISPR some poster was saying he believed CRISPR didn't work the way people thought it worked. He said it was simply killing cells that didn't have the desired mutation and biologists weren't realising that because of design errors in the experiments (or rather, sometimes mass cell dieoffs were being reported but not dwelled upon).
If CRISPR isn't actually editing the DNA but rather just selecting natural mutants that happen to have the desired edit, would that cause what's seen here?
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#7I believe George Church published some work several years ago now using whole genome sequencing after CRISPR, saying they had neglible off-site integration or other mutations.
But going back,the findings were much more measured than that- they still saw off-site integration.
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#8I seem to recall that in prior HN stories about CRISPR some poster was saying he believed CRISPR didn't work the way people thought it worked. He said it was simply killing cells that didn't have the desired mutation and biologists weren't realising that because of design errors in the experiments (or rather, sometimes mass cell dieoffs were being reported but not dwelled upon). If CRISPR isn't actually editing the D…
Don't think so. Originally the CRISPR mechanism was discovered in bacteria, which only have one cell. It doesn't make sense for bacteria's anti-virus system to kill it's only cell.
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#9Off target effects from CRISPR is not new. The method leverages DNA repair mechanisms in the cell to do the recombination. All errors involved in those DNA repair mechanisms (there are distinct ones) would apply here。
But if CRISPR cuts off a single DNA sequence, surely the repair mechanisms won't damage a random gene far away. My very limited understanding is this paper is reporting widely spread damage on the genome.
The original bacteria CRISPR can only cut off pre-defined sequences, but the artificial gene tech CRISPR can add and edit as well. I'm wondering if the later two modes are the sources of the genome damage.
Re: Crack in CRISPR Facade After Unanticipated in Vivo Mutations Arise
#10Off target effects from CRISPR is not new. The method leverages DNA repair mechanisms in the cell to do the recombination. All errors involved in those DNA repair mechanisms (there are distinct ones) would apply here。
But if CRISPR cuts off a single DNA sequence, surely the repair mechanisms won't damage a random gene far away. My very limited understanding is this paper is reporting widely spread damage on the genome. The original bacteria CRISPR can only cut off pre-defined sequences, but the artificial gene tech CRISPR can add and edit as well. I'm wondering if the later two modes are the sources of the genome damage.
> but the artificial gene tech CRISPR can add and edit as well.
I was under the impression that addition and editing capability were essentially done by injecting the sequence that is desired and performing the cut. Then you simply rely on the repair mechanisms to have a chance to put the new segment in instead of the old segment. Is that not the case?