Distribution of neuregulin-1 (nrg1) and erbB4 transcripts in embryonic chick hindbrain.

Interrhombomeric signalling has a role in development of the chick hindbrain. We have examined the transcript distributions of neuregulin-1 (nrg1), a signalling molecule with effects on nervous system development, and of one of its receptors, erbB4. Expression patterns of these two molecules are, in contrast to the situation in mouse, not consistent with a role in interrhombomeric signalling, but are consistent with a role in signalling between dorsal and ventral territories within individual rhombomeres. Other areas of potential nrg1-erbB4 signalling are the cerebellum, the caudal rhombic lip, and dorsolateral mantle in the caudal hindbrain. nrg1 is additionally expressed in motor neurons and erbB4 in rostral rhombic lip plus a subset of rhombic lip derivatives. Both molecules are also expressed in other parts of the nervous system and in nonneuronal tissue. The expression data presented will facilitate interpretation of future functional studies on nrg1-erbB4 signalling during hindbrain development.