CAN TWO EGGS BE FERTILISED TO FORM A ZYGOTE?

 So, one of my friends asked me this brilliant curious question one day - Instead of a sperm fertilising an egg, can an egg fertilise another egg? So, this post is mainly for her and many other inquisitive people out there wondering similar things. I have been having so many thoughts on this and the following is a small gist of my thoughts penned down. 

So let's say one were to take an egg, insert the DNA from another egg, and then insert centrosomes from another cell, is it possible for the cell to divide? Well, probably we might have to give it a mild electric shock. This is what is done in some cloning techniques. I mean, of course, there is no guarantee that this method is bound to work, but probably it might work? 

Replication can be done in the lab too but the issue is that there is not much understanding about gene regulation and reproduction. Most of us know about Dolly, the sheep which was the first mammal to be cloned, using the diploid nucleus from an adult tissue. Here, nuclear transfer was done. Dolly was the result of 1 out of 277 fusions - not a very good success rate, rite? 

But let's now suppose that two human eggs are successfully fertilised. Will the progeny be safe? I'll explain this with an example.

When both chromosome number 15 comes from mother, the child will be born with a genetic disorder called Prader Willi Syndrome (it is maternal uniparental disomy, a condition in which 2 copies of a chromosome come from the mother). 

If one gene from the same gender can cause so much problem, what will happen when all the genes are maternal? This is Genetic Imprinting. 

Today besides sheep, cats and monkeys have also been cloned. Since a diploid nucleus is used here, it is a mode of asexual reproduction. There has not been a successful replication of this in a normal human cell. Once all the gene regulation is understood clearly and this process is clearly defined, it can be done in humans. In case it happens in humans, then the donor will have to contribute all the 46 chromosomes. The recipient will have to contribute their mitochondrial DNA, which is less than 1 % and is a very small amount of extra chromosomal DNA. The recipient will carry the progeny and provide the progeny with nourishment. 

Of course, taking the haploid DNA from one egg and using it to fertilise the other seems like the most straightforward approach. 

Let's now think about two sperm fertilisation to form a zygote. Do you think it might be possible? Well, I think that this might not be possible, because an egg might be needed in order to supply organelles, cytosol and cytoskeleton. 

Well, what if, the nucleus was removed from the egg and a sperm's nucleus was implanted in the egg, then allowing the sperm to fertilise the egg? Will it work? Probably yes!

Considering ethics, there are laws requiring humane treatment of animals in research. I have also posted about this in one of my earlier posts, do check that out too, if you haven't yet!  If these are followed, doing this research on mice, would probably be legal.

 Doing the same on humans would obviously be more complicated. There would be a lot of controversy, but again coming to legality, it is unsure if it would be legal. Do let me know your views in the comments :) !