Production of live offspring from testicular tissue cryopreserved by vitrification procedures in Japanese quail (Coturnix japonica)1 Running title: Recovery of cryopreserved testes of Japanese quail

Cryopreservation of testicular tissue can be used for ex situ conservation of male germplasm of avian species. The possibility of using vitrification and transplantation of testicular tissue for fertility preservation and recovery was tested in Japanese quail. Testes were removed from week-old Japanese quail, transfixed on acupuncture needles, equilibrated with dimethyl sulphoxide, ethylene glycol and sucrose, plunged into liquid nitrogen, and stored in 2 ml straws. Cryopreserved tissue was warmed in sucrose solutions at room temperature or at 40°C. Fresh and cryopreserved tissue was transplanted subcutaneously into castrated, week-old recipients. Twenty of 21 recipients survived the surgery and 18 had viable transplants at maturity, with no difference in transplantation success between fresh and cryopreserved tissue. Fluid extrusion from 11 of the transplants was collected and inseminated surgically into the magnum of 22 quail hens and ten inseminations included foam from the proctodeal gland of the same recipients. Egg production in the two weeks after insemination was reduced and none of the hens inseminated with foam produced fertile eggs. Five hens inseminated without foam produced a total of eight live offspring, and four of these were inseminated with fluid extrusion from cryopreserved tissue