First published online December 8, 2005
Development 133, 106e (2006)
© The Company of Biologists Limited
Chitin support: scaffolding for new tubes
Insects breathe through a network of epithelial tubes, called trachea, that
transport gases around their bodies. In Drosophila, the uniform
expansion of these tubes during development requires the assembly of a
transient intraluminal chitin matrix. Now, on p.
163, Moussian et al.
report that chitin filament assembly depends on Knickkopf (Knk) and
Retroactive (Rtv), proteins that are also involved in the formation of the fly
cuticle. The researchers describe how knk and rtv mutants
develop severe tracheal tube size defects similar to those seen in
chitin-deficient embryos, and show that Knk, an apical GPI-linked protein, is
mislocalized in tube expansion mutants in which septate junction proteins are
disrupted. The researchers propose that septate junctions, which resemble
vertebrate tight junctions, ensure the correct distribution of the components
needed for chitin filament assembly and so ensure the uniform expansion of the
trachea.
Related articles in Development:
- Drosophila Knickkopf and Retroactive are needed for epithelial tube growth and cuticle differentiation through their specific requirement for chitin filament organization
- Bernard Moussian, Erika Tång, Anna Tonning, Sigrun Helms, Heinz Schwarz, Christiane Nüsslein-Volhard, and Anne E. Uv
Development 2006 133: 163-171.
[Abstract]
[Full Text]