Figure 4

Figure 4

ascl1b-2A-Cre, olig2-2A-Cre and neurod1-2A-Cre Cre recombinase activity in the 3 dpf larval midbrain and hindbrain. F3 or F2 adults were mated to the recombination reporter line ubi:Switch to generate double transgenic embryos. Confocal imaging of ascl1b-2A-Cre; ubi:Switch (a–a′′,b–b′′), control sibling ubi:Switch (c,d), olig2-2A-Cre; ubi:Switch (e–e′′,f–f′′) and neurod1-2A-Cre; ubi:Switch (g–g′′,h–h′′) larval midbrain tectum (t), cerebellum (c) and hindbrain (h). Arrows point to the ventricular zone lining the midbrain and hindbrain ventricles (v). Expression of ascl1b-2A-Cre earlier in brain development leads to nearly all descendant neurons expressing mCherry (a,b). No switching occurs in the absence of Cre (c–c′′,d–d′′). olig2-2A-Cre leads to mCherry expression in a subset of cells in the cerebellum (arrowheads), and neural progenitors lining the hindbrain ventricular zone and their descendants (e,f). In neurod1-2A-Cre mCherry expression is absent from the ventricular zone (v arrows) but present throughout neurons in the tectum, cerebellum (arrowheads) and hindbrain (g,h). Scale bars 50 μm.