Holy crap. The obvious use for this would be in vitro. However, I cannot wait to see how this affects those already born. Could it be used on someone who is a 7 year old to rid them of this? What if they’re 50? So cool. Can’t wait to see where this goes.
You are right (at the 8 cell stage you can still separate them and treat them one at a time, giving you multiple shots at IVF)
Two of the main issues regarding gene editing when not talking single cells are the transfer into the nucleus, and then accessing the DNA you want.
In bacteria, the DNA kinda just swims around in the cell, which makes editing easy if you can get the CRISPR/Cas9 complex in the cell. But animal cells have another membrane surrounding the DNA, making the transfer less than straightforward.
Regarding access: our DNA isn’t lying around like mom’s spaghetti, but rather pretty tightly packed around histones - a protein octamer.
This means that your target might not be reachable (the cell itself has 3 options iirc: slide the DNA over the surface of the histone, replace a part of the histone with an alternative, or remove the histone altogether) Since the way the DNA is wound around the histones affects gene activity (something tightly packed is not active, something in a loose area is getting transcribed into mRNA and therefore possibly active), you cannot just unwind all of it.
The only time this is not the case is during cell division, where the nucleus is getting dismantled so the DNA can be duplicated and both new cells can get their own copy. But many cells do not divide in an adult (except for a reservoir of stem cells which are there to replace lost cells)
from what i remember (it’s been a few years since i studied this stuff lol) you can only arrest the cell cycle (dismantling -> duplication of chromosomes -> separation of chromosomes -> completion of division) at specific points, and can’t go in reverse. Theres a whole cascade of signals, that when started, are running their way to specific checkpoints. if a cell is stuck for too long at any checkpoint, it commits suicide, because that’s THE sign for unrecoverable DNA damage. And if a cell starts ignoring checkpoints and suicide signals, it’s called cancer.
Many antibiotics work that way btw - they look a lot like nucleotides (A C G T), but if a bacterium adds them when copying instead of one of the “letters”, the machinery gets stuck, and the bacterium cant divide anymore. That gives the immune system time to kill them off. Bacteria replicate a lot and have no proofreading of what they are copying, so they are susceptible to this. Animal cells have proofreading AND the ability to correct an error, so we are fine.
I loved studying this stuff. i did NOT love the crapload of chemistry i had to learn, but even that was highly interesting.
Could it be used on someone who is a 7 year old to rid them of this?
No. Gene editing works in this case since they’re just working with a few cells. But a whole human is way more cells. Not only that, but the cells have already developed into structures that are much harder to access, and difficult to change. Any gene therapy may only affect a few cells.
On top of that, there’s also a bunch of ethical issues around altering a human when they’ve already formed, and we don’t really know if it would be possible to do so, or if it would make things worse.
Hard to say at this point. This early testing was on cells in a petri dish. It will take a lot of study to convert this to a treatment on living humans and determine the best time to intervene.
Holy crap. The obvious use for this would be in vitro. However, I cannot wait to see how this affects those already born. Could it be used on someone who is a 7 year old to rid them of this? What if they’re 50? So cool. Can’t wait to see where this goes.
And in the US, religious assholes want to ban IVF for exactly this reason, because it’s “playing God”.
“if your god wasn’t such a loser fuckup, we wouldn’t need to fix this mess”
The article mentions the technique worked on most (differentiated) skin cells they tested on, in addition to working on (undifferentiated) stem cells.
But, there’s a lot of steps between this article and any sort of treatment, if I understand correctly.
It might be easier to just edit the gametes before they form a zygote at all. That would also make consent for treatment much clearer.
Until someone who knows more tells me otherwise, no. It would have to be applied to a human at the stage of a single cell
You are right (at the 8 cell stage you can still separate them and treat them one at a time, giving you multiple shots at IVF)
Two of the main issues regarding gene editing when not talking single cells are the transfer into the nucleus, and then accessing the DNA you want.
In bacteria, the DNA kinda just swims around in the cell, which makes editing easy if you can get the CRISPR/Cas9 complex in the cell. But animal cells have another membrane surrounding the DNA, making the transfer less than straightforward.
Regarding access: our DNA isn’t lying around like mom’s spaghetti, but rather pretty tightly packed around histones - a protein octamer.
This means that your target might not be reachable (the cell itself has 3 options iirc: slide the DNA over the surface of the histone, replace a part of the histone with an alternative, or remove the histone altogether) Since the way the DNA is wound around the histones affects gene activity (something tightly packed is not active, something in a loose area is getting transcribed into mRNA and therefore possibly active), you cannot just unwind all of it.
The only time this is not the case is during cell division, where the nucleus is getting dismantled so the DNA can be duplicated and both new cells can get their own copy. But many cells do not divide in an adult (except for a reservoir of stem cells which are there to replace lost cells)
So, it’s all very complicated.
can we induce nucleus “dismantling” without inducing cell division?
(sorry if bad question, you’re way out of my depth)
from what i remember (it’s been a few years since i studied this stuff lol) you can only arrest the cell cycle (dismantling -> duplication of chromosomes -> separation of chromosomes -> completion of division) at specific points, and can’t go in reverse. Theres a whole cascade of signals, that when started, are running their way to specific checkpoints. if a cell is stuck for too long at any checkpoint, it commits suicide, because that’s THE sign for unrecoverable DNA damage. And if a cell starts ignoring checkpoints and suicide signals, it’s called cancer.
Many antibiotics work that way btw - they look a lot like nucleotides (A C G T), but if a bacterium adds them when copying instead of one of the “letters”, the machinery gets stuck, and the bacterium cant divide anymore. That gives the immune system time to kill them off. Bacteria replicate a lot and have no proofreading of what they are copying, so they are susceptible to this. Animal cells have proofreading AND the ability to correct an error, so we are fine.
I loved studying this stuff. i did NOT love the crapload of chemistry i had to learn, but even that was highly interesting.
No. Gene editing works in this case since they’re just working with a few cells. But a whole human is way more cells. Not only that, but the cells have already developed into structures that are much harder to access, and difficult to change. Any gene therapy may only affect a few cells.
On top of that, there’s also a bunch of ethical issues around altering a human when they’ve already formed, and we don’t really know if it would be possible to do so, or if it would make things worse.
Hard to say at this point. This early testing was on cells in a petri dish. It will take a lot of study to convert this to a treatment on living humans and determine the best time to intervene.
i can’t tell if you’re serious.