Sperm 'grown from embryonic stem cells'

Posted by Emma Woollacott

Newcastle - UK - British scientists claim to have created human sperm using embryonic stem cells.

The research was led by Professor Karim Nayernia at Newcastle University and the NorthEast England Stem Cell Institute (NESCI). While some doubt has already been raised over whether the cells are truly authentic sperm cells, the team stresses that the research is in its early stages.

Professor Nayernia said, "It will allow researchers to study in detail how sperm forms and lead to a better understanding of infertility in men – why it happens and what is causing it. This understanding could help us develop new ways to help couples suffering infertility so they can have a child which is genetically their own."

Stem cells with XY chromosomes were developed into germline stem cells which were then prompted to complete meiosis - cell division with halving of the chromosome set. These were shown, says the team, to produce fully mature sperm - In Vitro Derived sperm (IVD sperm).

The embryonic stem cells were cultured in a new medium containing retinoic acid, causing them to differentiate into germline stem cells. After further differentiation, claims the team, the cells expressed markers specific to primordial germ cells, spermatogonial stem cells, meiotic (spermatocytes) and post meiotic germ cells - sperm, in other words.

The IVD sperm cannot be used for fertility treatment, as this is prohibited by UK law.

"While we can understand that some people may have concerns, this does not mean that humans can be produced 'in a dish' and we have no intention of doing this. This work is a way of investigating why some people are infertile and the reasons behind it. If we have a better understanding of what's going on it could lead to new ways of treating infertility," adds Professor Nayernia.

The work is published today in Stem Cells and Development.