Conservation of a Threatened Indigenous Fowl (Kureko Dori) Using the Germline Chimeras Transplanted from Primordial Germ Cells

This is the first successful report on producing the endangered domestic fowl, Kureko Dori (KD), which is a Kumamoto prefectural natural treasure, using germline chimeras transplanted from primordial germ cells (PGCs) in practice. The attempt was made to produce germline chimeras between KD fowl, as a model of rare and/or endangered poultry, and common White Leghorn (WL) for the proliferation of KD individuals. The PGCs of KD were collected from embryonic blood at stages 13 to 16 (H & H) and preserved in liquid nitrogen until injection. A certain number of frozen-thawed PGCs were picked up under a phase contrast microscope, and injected into the peripheral vein of WL embryos (common poultry) at stages 12 to 14. We obtained one male and 6 females as the putative germline chimera, they were raised until sexual maturity, and the progeny test was performed by mating them with KD of the opposite sex to analyze the efficiency of germline chimera. The average rate of offspring originating from transplanted PGCs of KD was only 1.4%, and the maximum was 5.3% from all 577. These KD offspring derived from the KD-WL germline chimeras also achieved fertility as normal. These results show that rare and/or endangered birds can proliferate through producing germline chimeras between the same species of bird.