Scientists have taken major steps forward to creating an artificial embryo structure without using sperm or eggs, giving hope to infertile couples.
A groundbreaking experiment took skin cells from a mouse’s ear and implanted them in a female rodent’s womb, making it pregnant.
Although the US-led team produced a near-perfect embryo with the skin cells, it did not develop into a baby.
This advancement will require a lot more research as it is still in its early stages. It is nowhere near being done in people.
But the breakthrough does give future hope to as many as one in seven couples who struggle to start a family, often because of low sperm counts or poor-quality older eggs.
Scientists have taken major steps forward to creating an embryo without using sperm or eggs. A blastocyst-like form was made from adult mice cells. Pictured, an early stage embryo
However, rather than trying to artificially create a baby using just skin cells, the study was actually designed to shed light on the causes of infertility
Embryos unable to properly implant in the womb is a leading cause of failed pregnancies.
For the first time, the team at The Salk Institute and the University of Texas Southwestern Medical Center used a single cell to create a so-called ‘blastoid’.
These blastoids have the same structure as natural blastocysts and can even implant in the uterus, the scientists wrote in the journal Cell.
It will advance research into how life develops from a ball of cells and why pregnancies fail.
The way the 100 or so cells group together has profound implications for diseases later in life, such as Alzheimer’s.
Therefore, the research is also useful for understanding health problems in offspring.
Juan Carlos Izpisua Belmonte, a professor in Salk’s Gene Expression Laboratory, said: ‘These studies will help us to better understand the very beginnings of life; how early on in life a single cell can give rise to millions of cells and how they are assembled in space and time to give rise to a fully developed organism.
‘Importantly, this work avoids the use of natural embryos and is scalable.’
Dr Ronghui Li, co-first author, said: ‘The formation of blastoids mimics the natural developmental process.’
Cuiqing Zhong, co-first author, added: ‘I think this kind of resource is going to be very powerful for studying early development in mammals.’
Similar blastocysts have been created in the lab by the same lead scientist, Professor Nicholas Rivron of Maastricht University.
However, this work is novel because it uses a single adult cell, rather than just embryonic cells, and the blastoid implanted in the womb – where previous work has failed.
The adult cells were put into a chemical solution that prompted them to turn into stem cells which can turn into almost any kind of tissue in the body.
The researchers watched as the cells formed connections, and then became a ball, similar to a natural blastocyst.
Cells began making a protein called YAP, which is involved in the building of what could eventually become a placenta.
The blastoids cannot yet develop into functional embryos, rather disorganised tissue.
Independent experts said the research is an ‘interesting development’ on previous work from across the world.
However, they reiterated that science is a long way from creating an ’embryo’, which some see as ethically wrong.
Professor Alfonso Martinez Arias, Department of Genetics at University of Cambridge, said: ‘The work is an extension, or further elaboration, from published work, but an important one.
‘In this work, they obtained mouse blastoids with the three cell types, and they implanted in mouse wombs.
‘However… they do not show that the implanted structures go to term in mice or even that they develop into anything as recognisable as a mouse embryo.
‘In order to live up to the opening statement of helping inform issues around health problems, they would need to show that these contraptions develop beyond the stages that they show here.
‘If we don’t we shall be using hype to play with hopes.’
Dr Harry Leitch, stem cell biologist, Imperial College London, said: ‘I would caution against interpreting the current study as showing that embryos can be made from adult tissues.
‘This has the potential to raise undue ethical concerns, the structures made are not embryos, and the research is in mice not humans.’
Professor Rivron has previously said: ‘I do not believe in using blastocysts for human reproduction.’