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)
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.
The rhibosone is the powerhouse of the cell.
No, they are the factories of the cell, building proteins. :-)
The mitochondria are the powerhouse of the cell.