Recovery of fertility from adult ovarian tissue transplanted into week-old Japanese quail chicks

Fertility of cryopreserved ovarian tissue from immature chickens and Japanese quail has been recovered by transplantation. This is of special importance for non-mammalian vertebrates in which cryopreservation and in vitro maturationofoocytesarechallengingbecausetheiroogenesisischaracterisedbyvitellogenesis.Thisstudytestedwhether fertility of adult quail ovarian tissue could be recovered by transplantation. Ovaries were isolated from mature Japanese quail hens, trimmed, cut into 3- to 4-mm 2 pieces and transplanted into ovariectomised, week-old chicks. Recipients were administered an immunosuppressant for two weeks. Ten of 12 recipients survived until sexual maturity and seven laid eggs, but all stopped laying by 17 weeks of age. The age at first egg of recipients laying eggs (75.7 � 4.2 days)was greater thanthatofuntreatedhens(51.8 � 1.7days)andeggproductionofrecipientsduringthelayingperiod(21.7 � 5.7)wasless thanthatofuntreatedhens(60.8 � 3.5).RecipientswerepairedwithmalesfromtheWBlinefortestmating.Onlytwohens laid eggs during the test period but both produced 100% donor-derived offspring. This research demonstrated that the reproductive potential of ovarian tissue from adult quail hens can be restored by transplantation. Additional keywords: avian species, genetic conservation, transplantation.