Abstract

The homeodomain transcription factor Phox2b controls the formation of the sensory-motor reflex circuits of the viscera in vertebrates. Among Phox2b-dependent structures characterized in rodents is the nucleus of the solitary tract, the first relay for visceral sensory input, including taste. Here we show that Phox2b is expressed throughout the primary taste centers of two cyprinid fish, Danio rerio and Carassius auratus, i.e., in their vagal, glossopharyngeal, and facial lobes, providing the first molecular evidence for their homology with the nucleus of the solitary tract of mammals and suggesting that a single ancestral Phox2b-positive neuronal type evolved to give rise to both fish and mammalian structures. In zebrafish larvae, the distribution of Phox2b²⁺ neurons, combined with the expression pattern of Olig4 (a homologue of Olig3, determinant of the nucleus of the solitary tract in mice), reveals that the superficial position and sheet-like architecture of the viscerosensory column in cyprinid fish, ideally suited for the somatotopic representation of oropharyngeal and bodily surfaces, arise by radial migration from a dorsal progenitor domain, in contrast to the tangential migration observed in amniotes.

Links

Publisher Full Text

Authors

Coppola E, D'autréaux F, Nomaksteinsky M, Brunet JF

Institution

École Normale Supérieure, Institut de Biologie de l'École Normale Supérieure, Paris F-75005, France.

Source

The Journal of comparative neurology 520:16 2012 Nov 1 pg 3633-49

MeSH

Animals
Blotting, Western
Brain
Goldfish
Homeodomain Proteins
Immunohistochemistry
In Situ Hybridization
Mice
Mice, Transgenic
Solitary Nucleus
Taste Perception
Transcription Factors
Zebrafish
Zebrafish Proteins

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22473338