The stunning discovery has alarmed medical ethics campaigners, who described it as turning nature on its head. Researchers say the groundbreaking technology could be used to help women whose husbands are infertile but who do not want to use donor sperm.
Any babies born from the process would be female and genetically identical to their mother.
Taken to its extreme, it could lead to the science fiction nightmare of a female-dominated society where men have little or no role.
The news also creates a legal minefield for UK authorities which govern fertility treatments, because British laws do not cover the creation of an embryo without sperm.
The discovery was made by researchers from the Institute for Reproductive Medicine and Genetics in Los Angeles.
They were investigating new ways of genetically modifying embryos to grow into brain nerve cells, in order to give transplants to patients with Parkinson’s Disease.
Their experiments with mice triggered a form of asexual reproduction called parthenogenisis, which until now has happened only in creatures such as insects and frogs.
In normal human reproduction, an egg carrying 23 pairs of chromosomes, the building blocks of life, is fertilised by a sperm, which also carries 23 sets.
This crucial binding, creating 46 pairs of chromosomes, opens the way for cell division, the very beginning of human life.
But researchers Dr Jerry Hall and Dr Yan-Ling Feng managed to make eggs duplicate their own chromosomes to create the number needed to start cell division.
Several embryos were transferred to mouse ‘foster mothers’ where they developed successfully before being destroyed after 13 days.
Though the process has yet to be tested on human eggs, studies have already shown that they behave in a similar way to those of mice. The findings are due to be unveiled today at the annual meeting of the respected American Society of Reproductive Medicine in Florida.
They have been hailed as a new way of producing different kinds of cells for medical use.
Dr Michael Soules, president of the ASRM, said: ‘If this works with human eggs, there could be tremendous opportunities for clinical applications. I think everyone is going to find this work to be very exciting.’
But Dr Jacqueline Laing, expert in medical ethics from London’s Guild Hall University, said last night: ‘This is alarming. Just because scientists can do something, it does not mean that they should.
‘This process does not respect human life, in seeking either to procreate without the male or to use human eggs to turn them into some other part of the body for transplants.
‘It doesn’t respect reproduction and ordinary relations between men and women and the natural functions we have to protect human beings from arbitary creation. What are we expecting that any children born of this process will feel? If we go down this avenue, what else will be permissible?’
Paul Tully, of the Society for the Protection of Unborn Children, said: ‘Parthenogenisis is akin to cloning in a sense. It is the way lower orders of animals such as frogs and insects are able to reproduce.
‘It is entirely unknown for this to happen in humans and this is a very disturbing discovery. Apart from the ethical concerns of what was happening to these embryos without their consent, it could mean that, theoretically, it would be possible to eradicate men.’
He added: ‘What we are seeing here is the technological imperative – they are doing it just because they can. Is society going to curb this or are we going to see even more outlandish discoveries?
‘My fear is that, as with cloning, there will be horrific developmental abnormalities and accelerated ageing of these embryos. One dreads to think what they may suffer in the name of science.’
The Human Fertilisation and Embryology Authority, which governs IVF research in Britain, said a new law on parthenogenic embryos may be needed.
A spokesman said: ‘The view would probably be that no research could be carried out without permission and it certainly would not be licensed for clinical use unless it was proven safe and there were no ethical concerns.’