First published online May 5, 2004
Development 131, 1004e (2004)
© The Company of Biologists Limited
Setting the Hedgehog gradient
Morphogenetic gradients control many developmental patterning events in
Drosophila and vertebrates but how these gradients are established is
unclear. Torroja and co-workers report that Patched (Ptc), the receptor for
the morphogen Hedgehog (Hh), regulates the Hh gradient in the
Drosophila wing imaginal disc by mediating its endocytosis (see
p. 2395). The
researchers use mutations that block the endocytic pathway at different points
to show that Ptc internalises Hh in a dynamin-dependent manner, and that
internalised Hh and Ptc are targeted for lysosomal degradation. The
researchers also test whether the two proposed functions of Ptc - activation
of Hh signalling and sequestration of Hh - can be genetically uncoupled. In
the ptc14 mutant, in which Hh is not endocytosed,
expression of Hh target genes is normal, leading the researchers to conclude
that Ptc-mediated Hh internalisation does not have a major role in Hh signal
transduction.
Related articles in Development:
- Patched controls the Hedgehog gradient by endocytosis in a dynamin-dependent manner, but this internalization does not play a major role in signal transduction
- Carlos Torroja, Nicole Gorfinkiel, and Isabel Guerrero
Development 2004 131: 2395-2408.
[Abstract]
[Full Text]
