Test tube sperm an insight to fertility

LONDON: A team of British scientists claimed yesterday to have created human sperm using embryonic stem cells in a medical first they say will lead to a better understanding of fertility.

Researchers led by Karim Nayernia at Newcastle University and the North East England Stem Cell Institute developed a technique that allows the creation of human sperm in the laboratory.

They stressed that the sperm, developed from stem cells with XY chromosomes (male), would not be used for fertility treatment, as this is prohibited by British law and in any case is not their main interest.

"This is an important 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," Professor Nayernia said.

"This understanding could help us develop new ways to help couples suffering infertility so they can have a child which is genetically their own."

He said more investigation was needed to decide whether the so-called in-vitro derived sperm could be used as a fertility treatment, for example, for boys who became infertile after receiving chemotherapy for cancer.

While such a treatment would not be likely to be developed for at least a decade, Professor Nayernia said legislation should be put in place "sooner rather than later" to allow the technique to be licensed.

The team's work involved developing stem cells that had XY chromosomes into germline cells - cells that can can pass their genetic material to future generations.

These were then prompted to complete meiosis, or cell division, which produced "fully mature, functional sperm".

Stem cells are immature cells that can develop into different cell types.

The scientists tried to develop cells with XX chromosomes (female) in the same way but they did not progress beyond early stage sperm, called spermatagonia. The team concluded that the genes on a Y chromosome are essential for sperm maturation.

The research, published in the journal Stem Cells and Development, could lead to a better understanding of how genetic diseases are passed on.