Chimeric-competent, embryo-derived stem cell lines unveil the plasticity of pluripotency in rabbits. Oryctolagus cuniculus

Conventional rabbit embryonic stem cell (ESC) lines are derived from the inner cell mass (ICM) of pre-implantation embryos using methods and culture conditions established for primate ESCs (partial dissociation with collagenase and culture with FGF2). In the present work, we explored the capacity of rabbit ICM to give rise to ESC lines using conditions similar to those utilized to generate ESCs in mice. Overall design: In the present work, we explored the capacity of rabbit ICM to give rise to ESC lines using conditions similar to those utilized to generate ESCs in mice. Especially we compared the transcriptomes of rabbit ES cell lines obtained using (i) different dissociation protocoles : either partial dissociation with Collagenase or single cell dissociation with accutase and (ii) different culture conditions: 20% KOSR with FGF2, 10% KOSR and 10% FCS, 10% KOSR and 10% FCS with FGF2, or 10% KOSR and 10% FCS with LIF. Because we wanted to compare these transcriptomes to those of the pluripotent cells present in the embryo, we also analyzed the transcriptomes of Rabbit Day 4 Inner Cell Masses (ICM) , and Rabbit Day 6 Epiblasts. These two embryonic compartments were isolated from in vivo developped embryos using immunosurgery for Day 4 ICM, and microdissection for Day 6 Epiblasts. At Day 6 in the Rabbit, the Epiblast forms a monolayered epithelium of cuboid and polarized cells.