Modulation of zebrafish pitx3 expression in the primordia of the pituitary, lens, olfactory epithelium and cranial ganglia by hedgehog and nodal signaling
Article first published online: 11 JAN 2005
Copyright © 2005 Wiley-Liss, Inc.
Volume 41, Issue 1, pages 33–40, January 2005
How to Cite
Zilinski, C. A., Shah, R., Lane, M. E. and Jamrich, M. (2005), Modulation of zebrafish pitx3 expression in the primordia of the pituitary, lens, olfactory epithelium and cranial ganglia by hedgehog and nodal signaling. Genesis, 41: 33–40. doi: 10.1002/gene.20094
- Issue published online: 11 JAN 2005
- Article first published online: 11 JAN 2005
- Manuscript Accepted: 11 OCT 2004
- Manuscript Received: 15 JUN 2004
- NEI. Grant Numbers: EY12505, EY12163, T32 EY07102
- lens placode;
- anterior pituitary;
- lateral placodes
In this article we report the isolation of a novel zebrafish gene, pitx3, which plays an important role in the formation of several placode-derived structures. In wildtype embryos, pitx3 is first expressed in a crescent-shaped area in the anterior end of the embryo. At later stages, the primordia of the anterior pituitary, the lens, the olfactory sensory epithelium, and cranial ganglia express this gene. Pitx3 is not expressed in the more posterior preplacodal region that gives rise to the epibranchial, otic, and lateral line placodes. The dynamics of pitx3 in the anterior region of wildtype embryos suggests that pitx3 expression marks a common step in the formation of the pituitary, lens, olfactory placode as well as the trigeminal placode. Analysis of pitx3 expression in mutants lacking the hedgehog or nodal function demonstrates the differential dependence of pitx3 expression in these structures on nodal and hedgehog signaling. While the lens and trigeminal placodes express pitx3 in the absence of hedgehog and nodal signaling, there is no expression of pitx3 in the anteriormost ectoderm adjacent to the neural plate from which the anterior pituitary would derive. In mutants with impaired hedgehog signaling, the lens placode frequently extends into more anterior ventral regions of the embryo. genesis 41:33–40, 2005. © 2005 Wiley-Liss, Inc.