Homeobox genes in axolotl lateral line placodes and neuromasts

Autor(en)
Brian D. Metscher, R. Glenn Northcutt, David M. Gardiner, Susan V. Bryant
Abstrakt

Gene expression has been studied in considerable detail in the developing vertebrate brain, neural crest, and some placode-derived organs. As a further investigation of vertebrate head morphogenesis, expression patterns of several homeobox-containing genes were examined using whole-mount in situ hybridization in a sensory system primitive for the vertebrate subphylum: the axolotl lateral lines and the placodes from which they develop. Axolotl Msx-2 and Dlx-3 are expressed in all of the lateral line placodes. Both genes are expressed throughout development of the lateral line system and their expression continues in the fully developed neuromasts. Expression within support cells is highly polarized. In contrast to most other observations of Msx genes in vertebrate organogenesis, expression of Msx-2 in developing lateral line organs is exclusively epithelial and is not associated with epithelial-mesenchymal interactions. A Hox-complex gene, Hoxb-3, is shown to be expressed in the embryonic hindbrain and in a lateral line placode at the same rostrocaudal level, but not in other placodes nor in mature lateral line organs. A Hox gene of a separate paralog group, Hoxa-4, is expressed in a more posterior hindbrain domain in the embryo, but is not expressed in the lateral line placode at that rostrocaudal level. These data provide the first test of the hypothesis that the neurogenic placodes develop in two rostrocaudal series aligned with the rhombomeric segments and patterned by combinations of Hox genes in parallel with the central nervous system.

Organisation(en)
Institut für Paläontologie, Department für Evolutionsbiologie
Externe Organisation(en)
University of California, Irvine, Natural History Museum London, University of California, San Diego
Journal
Development Genes and Evolution
Band
207
Seiten
287-295
Anzahl der Seiten
9
ISSN
0949-944X
DOI
https://doi.org/10.1007/s004270050116
Publikationsdatum
1997
Peer-reviewed
Ja
ÖFOS 2012
106010 Entwicklungsbiologie
Schlagwörter
ASJC Scopus Sachgebiete
Genetics, Developmental Biology
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/0497a984-d7f6-4d3e-82f3-253da199a03f