Men No Longer Needed to Create Sperm
Thu, Jan 31, 2008
It looks like males will soon be irrelevant to the survival of the human race.
Scientists at the University of Newcastle have managed to create human sperm cells using a female embryonic stem cell.
The researchers, led by Prof Karim Nayernia, had previously created primitive sperm cells from male bone marrow. They’re currently working on making the cells from female bone marrow, which would be much easier and more practical than creating them from embryos.
The creation means that lesbian couples could soon have children that shared the DNA of both women, rather than having one male biological father. A sperm cell created from one partner could fertilize her partner’s egg.
There is some question about whether a sperm cell created from a female could produce viable, healthy offspring. The human female sperm cells could not in their current state produce offspring as they do not have the correct amount of genetic material. The team must next have the cells undergo meiosis to make sure the cells have the correct amount of genetic material.
That will likely only be a minor roadblock. Prof Nayernia has already overcome this problem with sperm cells created from male cells. In 2006, he used sperm created from embryonic stem cells to impregnate mice. The mice produced 7 pups, although one died and the other six had health problems.
Ok, so it may be overstating it a bit to say that males will be irrelevant. Just because we’re not technically needed to breed doesn’t mean women will no longer find men attractive, right? After all, we’re good for a lot more than just baby making. We’ve got tons to offer! For instance, just the other day I assembled a chair from Ikea, and it only wobbles a tiny bit when you sit on it. Also, I’m frequently asked to kill insects. I think we men have a bright future.
Info from Telegraph. Original article: http://www.telegraph.co.uk/scienceandte ... mbryo.html
Sperm cells created from female embryo
By Roger Highfield, Science Editor
Last Updated: 12:17AM GMT 01 Feb 2008
Lesbian couples could one day have children who share both their genes
Sperm cells have been created from a female human embryo in a remarkable breakthrough that suggests it may be possible for lesbian couples to have their own biological children.
British scientists who had already coaxed male bone marrow cells to develop into primitive sperm cells have now repeated the feat with female embryonic stem cells.
The University of Newcastle team that has achieved the feat is now applying for permission to turn the bone marrow of a woman into sperm which, if successful, would make the method more practical than with embryonic cells.
It raises the possibility of lesbian couples one day having children who share both their genes as sperm created from the bone marrow of one woman could be used to fertilise an egg from her partner.
Men and women differ because of what are called sex chromosomes. Both have an X chromosome. But only men possess a Y chromosome that carries several genes thought to be essential to make sperm, so there has been scepticism that female stem cells could ever be used to make sperm.
In April last year, Prof Karim Nayernia, Professor of Stem Cell Biology at Newcastle University, made headlines by taking stem cells from adult men and making them develop into primitive sperm.
He has now managed to repeat the feat of creating the primitive sperm cells with female embryonic stem cells in unpublished work.
The next step is to make these primitive sperm undergo meiosis, so they have the right amount of genetic material for fertilisation.
Prof Nayernia showed the potential of the method in 2006, when he used sperm derived from male embryonic stem cells to fertilise mice to produce seven pups, six of which lived to adulthood, though the survivors did suffer problems.
He is now optimistic about the prospect of lab-grown sperm from women.
“I think, in principle, it will be scientifically possible,” Prof Nayernia told New Scientist.
He said that he has applied for ethical approval from the university to use bone marrow stem cells from women to start experiments to derive female sperm.
“We are now writing the application form,” he said, adding that experiments will begin in Newcastle if and when they get approval.
However, Dr Robin Lovell-Badge, a stem cell and sex determination expert at the National Institute for Medical Research, Mill Hill, London, doubts it will work: “The presence of two X chromosomes is incompatible with this. Moreover they need genes from the Y chromosome to go through meiosis. So they are at least double-damned.”
In Brazil, a team led by Dr Irina Kerkis of the Butantan Institute in Saõ Paulo claims to have made both sperm and eggs from cultures of male mouse embryonic stem cells in the journal Cloning and Stem Cells.
The researchers have not yet shown that their male eggs can be fertilised to produce viable offspring, but they are thinking about possibilities for same-sex human reproduction.
If all these experiments pan out, then the stage would also be set for a gay man to donate skin cells that could be used to make eggs, which could then be fertilised by his partner’s sperm and placed into the uterus of a surrogate mother.
“I think it is possible,” says Kerkis, “but I don’t know how people will look at this ethically.”
The UK parliament is now debating changes to the 1990 Human Fertilisation and Embryology Act, and the government is under pressure to include an amendment that would allow the future use of eggs and sperm grown in the lab from stem cells.
However, a clause added to this amendment would restrict this to sperm from genetic males and eggs from genetic females.