Adaptation of induced pluripotent stem cell technology for avian species

Following the first report of induced pluripotent stem (iPS) cells from mouse, various mammalian-derived iPS cells have been established. In contrast, avian-derived iPS cells or iPS-like cells have been rarely reported. iPS cells can differentiate into various cell types (e.g., neural cells and hepatocytes) and proliferate indefinitely in culture. Unlike embryonic stem cells, iPS cells are generated from somatic cells, eliminating the need for embryos in their generation. Because somatic cells can be obtained from deceased individuals, iPS cell technology can be adapted for use in wild avian species, beyond its application in chickens. Our group previously reported the generation of chicken iPS cells from somatic cells using a modified-octamer-binding transcription factor 3/4 (Oct3/4), SRY-box transcription factor 2 (Sox2), Krüppel-like factor 4 (Klf4), MYC proto-oncogene (c-Myc), Nanog, and lin-28 homolog A (Lin28A). Developmental chicken eggs are a valuable resource for protein production. We may obtain valuable proteins from the chimeric developmental eggs of chickens using genome-edited or transgenic chicken iPS cells. Furthermore, our group established iPS cells derived from endangered avian species (Okinawa rail, Japanese ptarmigan, and Blakiston's fish owl) using modified-Oct3/4, Sox2, Klf4, c-Myc, Nanog, Lin28, and Klf2. Cells differentiated from iPS cells (e.g., neural cells and hepatocytes) can be used for drug testing in veterinary medicine and for evaluating sensitivity to infectious diseases and pollutants. We believe that iPS cell technology can be developed as a powerful tool for the conservation of endangered avian species.