GENTECH archive


Doing (it) without men ?

BBC    Wednesday, February 3, 1999 Published at 14:32 GMT

   Rodents make human sperm

   The research is directed at male fertility problems

   Researchers in Japan claim to have made rats and mice produce human
   Nikolaos Sofikitis explains his researchThe team at the Tottori
   University in Japan, say they implanted the human cells responsible
   for producing sperm - spermatogonia - into rat and mice testes in
   August 1998.
   Five months later human sperm was detected in the animals.
   Even more remarkable, if confirmed, is the disclosure that the
   spermatogonia used in the experiment were taken from infertile men.
   A letter has now been sent to the Japan Society of Obstetrics and
   Gynecology asking permission to see if the sperm can fertilize human
   Assistant professor Nikolaos Sofikitis said the key to success was the
   use of the animals' own eye cells in the operation.
   "Human sperm cells were protected by the eye cells," he said.
   There are a number of teams working in this
   area around the world. Previous attempts to grow human spermatogonia
   in rats and mice had failed due to the animals' white blood cells
   attacking the human transplant within the testes.
   But when some of the animals' own eye cells were implanted in the
   testes they killed off the white blood cells and allowed the human
   spermatogonia to grow and eventually produce sperm.
   The spermatogonia were taken from 18 infertile human patients and used
   in 10 rats and eight mice, Sofikitis said.
   There was much work ahead before it could be applied to humans, said
   the researcher, describing the experiment as a breakthrough.
   "I have to conduct many experiments before determining that these
   sperm can function properly," he said.
   Another researcher at the university, gynaecologist Yasuyuki Mio, said
   he had applied to the Japan Society of Obstetrics and Gynecology for
   permission to use the sperm produced by the rodents on human
   unfertilised eggs.
   "I would like to conduct many experiments by using sperm [grown in
   animals] to see how they grow and function in eggs," he said.
   Kazunori Ochiai, an assistant professor at Tokyo's Jikei University
   Hospital who serves as spokesman for the Japan Society of Obstetrics
   and Gynecology, declined to comment.
   "We have yet to receive a request letter, so I can't comment," he
   Professor Masao Miyagawa, who supervised Sofikitis' work, said it was
   up to society to decide whether to use such sperm for humans. "It is
   beyond our judgment," he said.

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