As published in the journal Developmental Cell, scientists at Newcastle University, England revealed that they have turned stem cells from am embryo into sperm which are capable of producing offspring.

    In the research, they used the sperm - created from stem cells - to fertilise eggs and produce babies. The babies in question were laboratory mice but the announcement raises the prospect that women could use the technique to have a human baby.

    The experts admit it is a long-term prospect. But the breakthrough will allow them to uncover the causes of infertility or testicular cancer, which are laid long before a baby is born.

    The professor behind the research believes that, when safe, the advance could help men with certain types of infertility to become fertile, to remain fertile for longer and, controversially, could even one day enable a lesbian couple to have children that, at the genetic level, are truly their own.

    The researchers isolated embryonic stem cells from an embryo only a few days old consisting of a cluster of cells. The cells were grown in a laboratory and screened to isolate the spermatogonial stem calls which were grown and then injected into female mouse eggs and grown in early stage embryos. Seven baby mice were produced, six of whom lived into adulthood.

    Problems with the procedure remain, however. The six mice that survived were all abnormally large or abnormally small, and were infertile. Many developed lung tumours and none lived for more than five months ¨C well short of the typical three-year mouse lifespan. Also, the sperm themselves had shortened tails and were unable to penetrate eggs on their own. Enditem

    (Agencies)