First published online September 30, 2004
Development 131, 2002e (2004)
© The Company of Biologists Limited
Parallel routes to ear development
The vertebrate inner ear develops from the otic placode, an ectodermal
thickening that forms next to the developing hindbrain. Now, Hans and
colleagues report that the paired box transcription factors Pax2a and Pax8
function synergistically in zebrafish otic specification (see p.
5091). They show that
zebrafish embryos in which Pax8 is depleted using morpholinos have mild ear
defects similar to those seen in pax2a- mutants but that
ear development is blocked in Pax8-depleted pax2a-
mutants. Other experiments reveal that expression of pax8 and
pax2a is regulated by the transcription factors Foxi1 and Dlx3b,
respectively, and indicate that Pax2a and Pax8 are the main downstream
effectors of the Fgf signals that induce otic specification. The researchers
propose that the Foxi1-Pax8 pathway jump starts otic specification, which is
then maintained by the Dlx3b-Pax2a pathway. Similar parallel pathways may act
in otic specification in other vertebrates.
Related articles in Development:
- Pax8 and Pax2a function synergistically in otic specification, downstream of the Foxi1 and Dlx3b transcription factors
- Stefan Hans, Dong Liu, and Monte Westerfield
Development 2004 131: 5091-5102.
[Abstract]
[Full Text]
