WEDNESDAY, Aug. 30 (HealthDay News) -- Researchers have produced normal and fertile rats using rat sperm produced in mice, according to a study published online Aug. 30 in the Proceedings of the National Academy of Sciences Early Edition.
Takashi Shinohara, M.D., Ph.D., of Kyoto University in Japan, and colleagues implanted mice with rat sperm stem cells, collected the developed sperm and microinjected the sperm (either fresh or cryopreserved) into rat eggs. They transferred 399 successful fertilizations to surrogate rat mothers.
The researchers found that 90 of the fertilizations successfully implanted, resulting in the birth of 15 healthy, fertile pups. All of the pups were conceived from cryopreserved sperm, suggesting that freezing might help select for more fertile cells, according to the authors.
"The spermatogonial transplantation technique has opened up several new possibilities in the study of spermatogenesis and can be used for treatment of infertility or transgenic animal production," the authors conclude.