Fig. 6.

Endogenous nr2f1b expression is necessary for resistance to Notch signaling inhibition.

(A) Schematic of the experiment. After morpholino (MO) intracranial injection and electroporation, fish were allowed to rest for 3 days, then treated with LY for 2 days and euthanized for quantification of the proportion of cycling NSCs. (B) Example images of the pallial surface in fish electroporated with a control MO (left) and an nr2f1b-specific MO (right) followed by 48 hours of LY treatment (dorsal whole-mount views). The brains were processed for immunohistochemistry for glutamine synthase (cyan, GS, labeling NSCs) and Pcna (red, proliferation), and the lissamine-tagged MOs (magenta) were imaged directly. Arrows point to electroporated NSCs. Scale bars, 10 μm. (C) Quantification of the proportion of proliferating NSCs as a function of the electroporated MO. NSCs electroporated with the nr2f1b MO are significantly more likely to proliferate after LY treatment than when electroporated with the control MO. Reported P value is derived from a χ² test. Violin plots are built from bootstrapped random sampling of the measured proportions to estimate the distribution. Control MO: n = 4 brains, 123 cells; nr2f1b MO: n = 5 brains, 581 cells.