North scientists offer hope for infertile couples

Jul 8 2009 by Helen Rae, The Journal

A BREAKTHROUGH in medical science is offering new hope to infertile couples.

Human sperm have been created using embryonic stem cells for the first time in a scientific development which will lead researchers to a better understanding of the causes of infertility.

But it will not be used to create human babies – and will not mean the end of men, they said.

A team of 20 researchers, led by Prof Karim Nayernia at Newcastle University and the NorthEast England Stem Cell Institute (NESCI) have developed a new technique to grow sperm from embryonic stem cells.

Researchers saw the cells, which were treated with acid, begin to split and dive then eventually push out a tail and begin to move. They called for the introduction of laws “sooner rather then later” to control how the research is used.

Prof Nayernia said: “This is an important and exciting development as 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.

“It will also allow scientists to study how cells involved in reproduction are affected by toxins, for example, why young boys with leukaemia who undergo chemotherapy can become infertile for life – and possibly lead us to a solution.”

It is believed that within the next five to seven years infertile men could be helped by the pioneering research.

The team also believe that studying the process of forming sperm could lead to a better understanding of how genetic diseases are passed on.

“Infertility in men has been rising in the last 20 years, particularly in the Western world, and this could be down to a number of environmental and genetic factors,” explained Prof Nayernia.

“This research is the first system which is able to look at the genetic and environmental influence, which is a key issue when looking into infertility.”

In the technique developed at Newcastle, stem cells with XY chromosomes (male) were developed into germline stem cells which were then prompted to complete meiosis – cell division with halving of the chromosome set. These were shown to produce fully mature, functional sperm called scientifically, In Vitro Derived sperm (IVD sperm). In contrast, stem cells with XX chromosomes (female) were prompted to form early stage sperm, spermatagonia, but did not progress further.

This demonstrates to researchers that the genes on a Y chromosome are essential for meiosis and for sperm maturation.

The IVD sperm will not and cannot be used for fertility treatment.