Project description:Primordial germ cells (PGCs), major cell resource used in the production of germline chimeras in birds, have been used in conservation of avian genetic resources and production of transgenic animals. Numerous bird species have been put on the brink of extinction due to habitat loss and degradation caused by environmental destruction and climate change, but research on PGCs is limited to specific poultry, such as chickens. Although it has recently been expanding to various bird species, it is still difficult to utilize PGCs due to biological differences and difficulties in in vitro long-term culture. Here, we constructed a single-cell landscape of chicken gonadal PGCs with established long-term culture systems of PGCs and compared them with those of the vocal learning wild bird, the zebra finches. Our results identified the interspecific differences in signaling pathways in gonadal PGCs and somatic cells, respectively. In particular, the NODAL and insulin signaling pathways were more active in zebra finch than in chickens, whereas the FGF downstream signaling pathway known to be important for the proliferation of chicken PGCs, was more active in chickens. These differences may contribute to optimizing the in vitro culture conditions of zebra finch PGCs. This study is the first cross-species single-cell transcriptomic analysis targeting birds, and laid an essential groundwork to contribute to the restoration of endangered birds and the production of transgenic birds by securing sufficient PGCs from various bird species in the future.
