(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 3. Wnt2b suppresses premature neurogenesis induced by an inactivation of Notch
signaling. (A-L) Effects of DAPT and Wnt2b on progenitor cell differentiation.
The retinal explants were prepared from E5 retina electroporated with control
(A,B,E,F,I,J) or Wnt2b-expressing (C,D,G,H,K,L) provirus vectors, and were
cultured for 2 days in the absence (A,E,I,C,G,K) or presence (B,F,J,D,H,L) of
DAPT, a
-secretase inhibitor that blocks Notch signaling. The sections
were stained for visinin (green), and Hu (purple) in A-D, for Pax6 (green) and
Chx10 (purple) in E-H, and for BrdU (green) and phosphorylated histone H3
(purple) in I-L. In the control explants, the DAPT treatment induced premature
neuronal differentiation, as revealed by the increase of neuronal markers (B)
and a decrease of retinal progenitor cell markers (F). In the Wnt2b-expressing
retinal explants, however, a large population of the cells still co-expressed
the progenitor markers (H) and incorporated BrdU (L). (M-P) Effects of a
dominant negative Delta1 and Wnt2b on retinal progenitor cell differentiation.
The optic vesicles were electroporated with provirus vectors encoding control
RCASBP (A,B) in M, RCASBP (A) encoding a dominant-negative form of Delta1 and
RCASBP (B) in N, RCASBP (A) and RCASBP (B) encoding Wnt2b in O, or RCASBP (A)
encoding a dominant-negative form of Delta1 and RCASBP (B) encoding Wnt-2b in
P. The retinas were fixed at E5, and sections were stained for visinin (green)
and Hu (purple). Note that Wnt2b completely suppressed the effect of the
dominant-negative Delta in promoting the neurogenesis. (Q-T) Effect of Delta1
and Wnt2b on Müller cell differentiation. Note that Wnt2b suppressed the
effect of Delta1 in inducing Müller glia differentiation when
co-expressed in the same explants. (U) Percentage of BrdU+ cells in the
explants expressing each construct (n=4). Scale bars: 30 µm.