Avian-induced pluripotent stem cells derived using human reprogramming factors.

Avian species are important model animals for developmental biology and disease research. However, unlike in mice, where clonal lines of pluripotent stem cells have enabled researchers to study mammalian gene function, clonal and highly proliferative pluripotent avian cell lines have been an elusive goal. Here we demonstrate the generation of avian induced pluripotent stem cells (iPSCs), the first nonmammalian iPSCs, which were clonally isolated and propagated, important attributes not attained in embryo-sourced avian cells. This was accomplished using human pluripotency genes rather than avian genes, indicating that the process in which mammalian and nonmammalian cells are reprogrammed is a conserved process. Quail iPSCs (qiPSCs) were capable of forming all 3 germ layers in vitro and were directly differentiated in culture into astrocytes, oligodendrocytes, and neurons. Ultimately, qiPSCs were capable of generating live chimeric birds and incorporated into tissues from all 3 germ layers, extraembryonic tissues, and potentially the germline. These chimera competent qiPSCs and in vitro differentiated cells offer insight into the conserved nature of reprogramming and genetic tools that were only previously available in mammals.