- Mice have been used to produce viable monkey sperm using
tissue transplanted from the testes of macaques.
-
- The US scientists involved say their work might one day
help to conserve animals that are facing extinction.
-
- It might also be possible to grow human sperm in mice,
although the team agree this would be a controversial move.
-
- The researchers, from the universities of Pennsylvania
and California, report their studies in the latest issue of the journal
Biology of Reproduction.
-
- In 2002, the same team produced goat and pig sperm from
mice. It was the first time that sperm had been produced outside the original
animal.
-
- Testis transplant
-
- The latest procedure involves transplanting a tiny amount
of testicular tissue from an immature rhesus macaque monkey under the skin
of a lab mouse.
-
- Ina Dobrinski, of the University of Pennsylvania, and
colleagues transplanted the tissue into mice that had deficient immune
systems, so that it would not be rejected.
-
- "We started this work with primate testis after
we had success with domestic animals," Professor Dobrinski told BBC
News Online.
-
- After seven months, the testes grafts on the backs of
the mice were seen to produce viable sperm.
-
- Grafting immature testis tissue appears to work because
the host mouse had been castrated, Dobrinski says.
-
- This boosts levels of the brain hormones that switch
on sperm production, so the young tissue grows rapidly. The technique is
expected to work on adult testis grafts, too.
-
- The Pennsylvania group will now try the procedure on
testis tissue from domestic cats, as a trial for endangered big cats that
rarely survive to reproductive age in captivity.
-
- The technique could also produce offspring from other
endangered species or valuable livestock, even if only immature males exist.
-
- The latest work with primates will help reduce the number
of such animals used in laboratories.
-
- Of mice and men
-
- "The main benefits we see are that this approach
provides a system to study and manipulate primate spermatogenesis, thereby
minimising the need for experimentation in primates," Professor Dobrinski
says.
-
- In theory, human testis tissue grafted on to mice could
produce sperm.
-
- The technique may also provide a way of testing toxins
or male contraceptive drugs on sperm development.
-
- Prepubescent boys undergoing treatment for cancer that
will render them sterile could benefit, Professor Dobrinski suggest.
-
- Their immature testis tissue could be removed prior to
treatment and transplanted on to mice for sperm production.
-
- Theoretically, it could enable a boy to become a father
before he reached puberty.
-
- © BBC MMIV
-
- http://news.bbc.co.uk/2/hi/science/nature/3458533.stm
|