|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 6. A model for effects of Patched (Ptc) on neural patterning. (A; left half)
Shh emanating from the notochord (N) induces formation of the floor plate
(FP), and subsequent shh expression in the FP generates a
ventral-dorsal activity gradient of Shh (as indicated by the density of the
blue dots). (B; left half) The activity gradient of Shh promotes the
specification of a series of ventral cell types: p0, p1, p2, pMN and p3, which
are progenitor domains from which distinct V0 neurons, V1 neurons, V2 neurons,
motoneurons and V3 neurons are generated respectively. Production of a mutated
form of the Shh receptor Ptc (Ptc1
loop2; A; right half;
light green), which does not bind Shh but antagonizes its signaling, causes
cell-autonomous abnormal dorsal spread of Shh and (B; right half)
ventral-todorsal switches in neural progenitor identity. Modified with
permission from Briscoe et al. (Briscoe et
al., 2001).
|
