Reproductive biologists at Kyoto University have succeeded in producing the first animal offspring with transgenic material carried directly from sperm stem cells “infected” by a retrovirus. Some of the resulting transgenic mice reproduced and passed on the new genetic material to their offspring. The team of researchers, headed by Dr. Takashi Shinohara, injected the retrovirus into the seminiferous tubules in the testes of immature male mice. The retrovirus was taken up by the sperm stem cells, which went on to produce sperm with the transgene.
