Ban on scientists trying to create three-parent baby

[Ivan Seeking]

Scientists have created the first pregnancy that would have produced babies with three genetic parents.

But after triplets formed in a woman's womb, one foetus was aborted and two later miscarried. Now work on the process, called human nuclear transfer, has been called off after the authorities realized how close scientists in China were to achieving the birth of a three-parent child.

http://news.independent.co.uk/world/middle_east/story.jsp?story=453121

 

[Monique]

Well, first of all.. it is not really three genetic parents.. maybe a little..

Basically what happens is that the wife has eggs with bad cytoplasm, that is why they go to a donor and get a healthy egg. They then take out the chromosomes of that donor egg, put in the chromosomes of the future dad and mom and let the egg develop.

The genetic contribution of the donor is the mitochondrial DNA. I think I once saw a documentary of a child born in this way??


I don't really see what is so controversial about this that they have banned it?? I mean, miscarriges happen, so do multiple births, especially after IVF. There must be another reason.. exactly which countries banned it?

 

[Monique]

Ah! Maybe I know why they want to ban this. This technique allows gay couples to get children of their own! Two males can get their own genetic baby for instance.

I think it is really interesting why they banned this, anyone knows more details??

 

[Monique]

Oh, I didn't realize there was a complete article link underneath that little header, I just read it, here is why it was banned and where:

The practice had already been outlawed in Britain, amid fears that it could lead to human cloning, in America and in most other countries.

Just how could this lead to human cloning that IVF doesn't??

ponents say scientists are "playing God'' and any child born through the process could suffer severe psychological and physical damage.

Oh, common, that is the same thing that was said against IVF..

I don't see any objections to the technique perse. The question is, what happens to the integrity of the DNA when it is transferred from one egg to the other, and is all the donor genomic DNA taken out completely? Or could by sheer stress parts break off and cause genetic defects by gross chromosomal abnormalities?

 

[Njorl]

How well is the purpose of mitochondria understood?

I don't know anything about them, except that they are passed from the mother.

Normally, a child gets half of its nuclear DNA from the mother, and all of its mitochondrial DNA. Is it possible that there needs to be a certain amount of compatibility between the two? Perhaps evolution has assured that the mitochondria can always do their job correctly provided the mother's DNA is present in the nucleus, but it will fail if the DNA is radically different? I also considered that the mitochondria might have to match the body providing nourishment, but the success of surogate mothering rules this out I guess.

Just guessing wildly,
Njorl

 

[Monique]

Good question, but I would highly doubt that there is a connection. Mitochondria are the energy-producing machines in the cell, they work autonomiously (sp?). And besides that, after every generation the contribution of the original mother halves.. IF there is not a tight correlation.. I have never seen any literature on the subject.

 

[Njorl]

Well, I've exhausted my ideas for possible objections. You may proceed

Njorl

 

[Monique]

hehe, ok, I will. But remember that I'll point my finger towards you if anyone finds out.

 

[Another God]

I'm pretty sure the mitochondtria would create no problems. They are highly conserved and basically the same in ever human on earth.

These sorts of reactions really annoy me. Particularly when the reaction is cries of "Playing God". Nothing bothers me more. I think the only reason people say this, is because they heard someone else say it, and seems to carry weight behind it (probably because it sounds like God disagrees with it), but if you then ask them what exactly 'Playing God' means...they normally don't have a clue. its just a common used catchphrase.

I doubt very highly, that these people even know what God wants.

 

[Njorl]

Yeah, I doubt many real cowboys objected to me playing cowboy when I was a kid. Why should God care who's playing him?

Njorl

 

[Zero]

Is there some sort of benefit to this sort of thing?

 

[Another God]

well, apparently so. They did it to help someone have a kid who otherwise couldn't. They take someone elses egg, and change the DNA in it.

 

[Zero]

Originally posted by Another God
well, apparently so. They did it to help someone have a kid who otherwise couldn't. They take someone elses egg, and change the DNA in it.

DUH! Never mind, dude, I am too tired to read, apparently!

 

[Monique]

I still don't understand why the article implies that this would get us one step closer to cloning??

In fact it takes us one step further away from it, since we would have another technique to join the list to be tried before resorting to cloning..

I DO think it is kinda cool that two guys would be able to get kids of their own :P

 

[LURCH]

Originally posted by Monique
Ah! Maybe I know why they want to ban this. This technique allows gay couples to get children of their own! Two males can get their own genetic baby for instance.

I think it is really interesting why they banned this, anyone knows more details??

This is just a guess, but perhaps it was banned because of the unprecedented genetic makeup the offspring would have. I know the article goes on to say that it was banned because of fears related to cloning, but I think this was merely the reporter's opinion being expressed. It seems to me that the real concern most folks would have is the fact that, as far as we know, no human being has ever been the product of 3 different genetic contributors. Because the current definition of "species" is largely a genetic one, this could raise questions as to whether such an individual is truly human, or some new creature. Still a bit silly, if you ask me.

 

[Monique]

as far as we know, no human being has ever been the product of 3 different genetic contributors

Right, you are kidding me, right? Let me count my genetic contributors, mom, dad, dads mom, moms dad, moms mom, dads dad, dads dad dad, moms mom dad. Get the point?

The only thing that stays constant in vertical transmission is the mDNA that is passed on from female to offspring and the y-chr that is passed on from dad to son. The rest is all strange people contributing their share of genetic information.

Actually, it is not even THAT sure that sperm doesn't contribute in mDNA, some recent research has shown that sperm in fact DOES transfer it mDNA.. only a small percentage of the total amount though.

 

[Ivan Seeking]

Originally posted by Monique
I DO think it is kinda cool that two guys would be able to get kids of their own :P

Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock Future shock

I thought I was impervious but this one surprises me.

 

[Monique]

Funny though, isn't it? I'm betting all my money on it, this is why it is getting banned.

 

[Another God]

You are forgetting imprinting though.

Trying to create an embryo from just male DNA, or just Female DNA means that they would have identical imprinting (Gene silencing etc) and so you would end up with a lot of disorders. This needs to be fixed before we will be able to do that.

 

[Monique]

Good one Another God! I forgot imprinting!
I should have thought of that myself..

 

[eagleone]

Let’s take a look on this ”God play” :),
lets say we take few chromosomes from one (egg or sperm cell, in most favorable momet for that),
and inject it and replace it with the same chromosomes of another being’s let’s say egg cell , and
proceed with a insemination.

Well hypothetically we want get 1/3 of all of the “parents”, but let’s say ½ and two ¼, it’s not so bad ...

 

[Monique]

no, not bad.. but a thing to keep in mind is imprinting of genes.. I don't think much is known about this is organized in a germ cell, it might give rise to serious genetic disorders.. even though all the chromosomes are present.

 

[Monique]

But it still holds no objections for this technique.. as long that only male and female germ cells are used.


Btw, that is also why this technique could be linked to cloning: for cloning you'd have to reset the imprinting of a cell.

 

[LURCH]

Originally posted by Monique
Right, you are kidding me, right? Let me count my genetic contributors, mom, dad, dads mom, moms dad, moms mom, dads dad, dads dad dad, moms mom dad. Get the point?

But not direct contributors. No human has had three parents. The genetic contributors in your past all came two at a time, and their genetic compatability was assured by the fact that they had mDNA and the maternal (egg) donor were one and the same. Mixing an egg from one female with mDNA from another has never been done, and so we don't know what the result will be. I don't think this has ever been tried on animals, has it? So I think the unknowns involved are what provoked the ban.

 

[Monique]

I am pretty sure they have tried it on animals, and mDNA is highly conserved.. I really don't think that is an issue. Anyone can tell us whether mDNA imprinting exists? Which diseases have been identified as having some mDNA disorder?

 

[Another God]

I have never heard of mitochondrial imprinting, and since I only just had lectures, by the one lecturer on both topics of Imprinting, and mtDNA, and he didn't mention the Imprinting OF mtDNA suggests to me that mtDNA doesn't have imprinting. Besides, Imprinting is a phenomenon that depends on which parent the genes are inherited from...mtDNA is haploid and only inherited from the mother. Imprinting it would result in complete gene loss.

PS: MtDNA and Egg donor DNA are different in every generation. I mean, the mtDNA stays the same (no recombination), but the DNA that gets passed down in every generation, could conceivably, by some fluke, be the DNA inherited from the females father every generation. In which case, the DNA being passed down with the mtDNA will be different in every generation.

So no, there is no compatibility assurance with mtDNA and the genomic DNA in nature.

As said by monique and myself already: mtDNA is highly conserved and so if someone is alive, then they have sufficiently compatible genomic DNA to work with any mtDNA.