Fig. 1 - Supplemental 2

Transient activation of Ventx reprogramming factor. (A) Top: At one-cell stage Ventx-GR mRNA is injected together with mRFP mRNA (used as a tracer), which expression throughout the embryo (here shown at 1 day post-fertilization [dpf]) is a proxy for Ventx-GR expression. (B) Bottom: Immunofluorescence analysis show that Ventx protein can be visualized in fixed embryos with the help of an antibody (Ab) directed against the HA tag linking Ventx and GR (and visualized by a second Ab linked to a green fluorescent marker). Upon addition of dexamethasone (DEX) at 1 dpf embryos, Ventx is released from its complex with cytoplasmic chaperones and diffuses into the cell nucleus, resulting in a pointillist image of the nuclei (middle). At 2 dpf, after washing out DEX, Ventx protein is no longer detected and the pointillist image is lost (right). Note that in all pictures the asterisk (*) indicates the eye. Scale bars and body axes (a: anterior; p: posterior; d: dorsal; v: ventral; l: left; r: right) are shown.