TDK conference 2016

The aim of this study was to take an insight into the in vitro poultry genetic conservation. Nowadays, the only practically used preservation method is cryopreservation of avian semen. Sperm cells only contain Z chromosome, females are heterogametic (ZW), and therefore the original genotype cannot be regained in a 100% even by 6 or 7 backcrosses. Because of the large amount of yolk, it is impossible to freeze the female oocytes and embryos that contain W chromosome which restrain the opportunity of cryobanking. Therefore an alternative method is needed to solve the preservation of female avian genetic material. Orthotopic transplantation in newly hatched chicks may be a suitable method. The structure of avian ovary is very similar to the adult mouse’s, whose ovary can be cryopreserved and transplanted.

It is proved that not all breeds are suitable to be recipients. The Tetra sl/Tetra sl, Plymouth/New Hampshire, White Leghorn/New Hampshire, White Hungarian/Yellow Hungarian donor/recipient pairs were appropriate, so indigenous breeds with each other, and intensive genotypes with each other compose successful combinations.

The aim was to form a donor/recipient pair which is capable of preserving the female genotype. We observed the genetic distance between the pairs of intensive genotypes and compared it with the genetic distance between indigenous breeds. According to the results, we tried to create a donor/recipient combination which can be efficient in transplantation. Yellow Hungarian/White Leghorn gonadal tissues were grafted first to check if the organs reject or not. The implanted organs adhered, and a histological examination proved that ovaries and testicles are capable of producing gametes. Thanks to the success of the adhesion, the next group is raised up and will be fertilized with the semen of the same breed. The origin of the offspring will be examined.

My roles in this work were the pre- and postoperative treatments, assistance during the surgery (prepare donors and recipients, anesthetize the animals, remove the vitelline sac and make the individual marking) and steroid and immunosuppressant treatment. In preoperative examinations I had to dissect died embryos and peri-hatched eggs.

In this research we formed the first pair-Yellow Hungarian/White Leghorn- which is suitable for chicken gene conservation. Further aim is to find the best recipient to all indigenous chicken breeds.