Fig. 2. Shh inactivation in the peripheral retina is associated with
increased cell cycle exit and depletion of the RPC pool. (A-L) In situ
hybridization on wild-type and
-Cre;Shh/c
retinas at E14 and P0. (A-D) Gli and (E-H) cyclin D1 expression are
downregulated in the peripheral retina of mutant mice at both ages (between
arrowheads in B,D,F,H). (I-K) In situ hybridization for Rax
expression to mark the neuroblast layer, which by P0 is reduced in thickness
in the peripheral retina of the mutant mice (between the arrowheads in L). (M)
The number of S-phase cells is reduced in the peripheral retina of the mutant
mice at E14. (N) The number of birthdated cells is increased in the peripheral
retinas of mutant mice. RPC were labelled at E13 with BrdU and the number of
heavily labelled nuclei was counted in the central versus peripheral retina at
P0. *P<0.005. Scale bar: 100 µm.