First published online December 7, 2007
Development 135, 103e (2008)
© The Company of Biologists Limited
Calcium signals early asymmetry
Although vertebrates look bilaterally symmetrical, their internal organs
are placed asymmetrically. In some organisms, Ca2+ signalling and
cilia function in the embryonic node have been implicated in the establishment
of this left-right (LR) asymmetry. Now, Schneider and colleagues report that
Ca2+ fluxes also have a conserved function in LR patterning before
node formation (see p.
75). In zebrafish embryos, Kuppfer's Vesicle (KV), which is derived
from the dorsal forerunner cells (DFCs), is homologous to the node in mice and
chicks. The researchers show that endogenous Ca2+ is released in
the DFC region after the onset of gastrulation but before KV and cilia
formation. The inhibition of this early Ca2+ release, the
researchers report, disrupts KV formation, which alters the expression of
asymmetric markers and the asymmetric placement of internal organs. Other
experiments indicate that β-catenin inhibition is the target of this
early Ca2+ signalling. Finally, the researchers identify DFC-like
cells in Xenopus embryos and provide evidence that early
Ca2+ signalling is a conserved feature of LR patterning.

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
Related articles in Development:
- Calcium fluxes in dorsal forerunner cells antagonize β-catenin and alter left-right patterning
- Igor Schneider, Douglas W. Houston, Michael R. Rebagliati, and Diane C. Slusarski
Development 2008 135: 75-84.
[Abstract]
[Full Text]