Offspring produced from orthotopic transplantation of chicken ovaries.

The loss of avian genetic variation and the threat of disease lend urgency to the cryopreservation of remaining poultry stocks. However, techniques for freezing ova and embryos are not available for birds, and the recovery of genetic material has been a major obstacle to cryopreservation. To overcome this problem, we transplanted chicken ovarian tissue just after hatch with or without subsequent treatment of the recipient with an immunosuppressant. Nine of 12 hens in the nonimmunosuppressed group and 6 of 9 birds in the immunosuppressed group produced eggs, whereas 3 hens in each group produced donor-derived offspring. These results suggest that transplantation of ovarian tissue of chickens is possible if performed just after hatch. This finding should allow efficient cryopreservation of female germ cells in chickens with regeneration in live birds. In addition, ovarian transplantation could be useful for studies in genetics or developmental biology or could provide convenient access to the female germline for genetic manipulation.