by Daniel Cossins

04 June 2016


from SCI-HUB Website

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jasper james/getty




No disease,

no natural conception,

no mind of your own.

Imagine a world without sex and disease,

and where all of our brains are networked.

It sounds wonderful,

but it will bring

a new set of moral questions...



Rumors of the end of sex are probably premature.


It has served us well so far, and besides, we are biologically programmed to want it. But when it comes to making babies, it is no longer the only option - and reproduction without sex looks set to become increasingly common.

Last year, human sperm and egg precursor cells were created by reprogramming adult skin cells.


Ethical concerns stopped the researchers from coaxing those cells into fully functional sperm and eggs, but the feat seems to have been achieved in mice:

a team in China has reported using stem-cell- derived sperm to sire healthy mouse pups.

What would happen if the trick could be safely repeated in humans?


That would be a genuine cure for infertility, says reproductive biologist Allan Pacey at the University of Sheffield, UK. It would also mean same-sex couples could conceive without the help of donors.

It even raises the prospect of individuals procreating alone, if we could make sperm from a woman's stem cells and eggs from a man's stem cells.


The offspring wouldn't be clones of the person concerned, since DNA is shuffled every time you create a sex cell. Even so, it's not a good idea, says Pacey - self-fertilization is tantamount to inbreeding, because it halves the genetic diversity available to the child.

Sexless reproduction might also appeal to people who can conceive naturally, because the random shuffling of DNA when sex cells are made can lead to problems. Every year millions of babies are born with a disability caused by genetic defects, and many more inherit gene variants that predispose them to serious illness.

Parents-to-be can already have embryos, created in vitro, screened for genetic abnormalities before they are implanted in the uterus. Using stem cells would make it easier to produce lots of eggs, which in turn makes pre-implantation checks a more viable option.

But will this application ever be allowed? Pacey suspects not, given the strength of opposition to destroying embryos.

Henry Greely, director of the Center for Law and the Biosciences at Stanford University, California, and author of The End of Sex and the Future of Human Reproduction, begs to differ.

He anticipates that stem cells will first be used to help people who are unable to make eggs or sperm.


Once this is approved, he says, other applications are likely to follow - particularly in the US, where "off-label use" of any approved medical product is allowed.

Peer pressure might even persuade people that natural conception is irresponsible, leading fertility clinics to capitalize by imploring us to,

"have the best child you can".

"This is going to change humanity," says Greely, "so it's something people need to pay attention to."