RRC ID 4122
Author Hutchinson SA, Cheesman SE, Hale LA, Boone JQ, Eisen JS.
Title Nkx6 proteins specify one zebrafish primary motoneuron subtype by regulating late islet1 expression.
Journal Development
Abstract The ability of animals to carry out their normal behavioral repertoires requires exquisitely precise matching between specific motoneuron subtypes and the muscles they innervate. However, the molecular mechanisms that regulate motoneuron subtype specification remain unclear. Here, we use individually identified zebrafish primary motoneurons to describe a novel role for Nkx6 and Islet1 proteins in the specification of vertebrate motoneuron subtypes. We show that zebrafish primary motoneurons express two related Nkx6 transcription factors. In the absence of both Nkx6 proteins, the CaP motoneuron subtype develops normally, whereas the MiP motoneuron subtype develops a more interneuron-like morphology. In the absence of Nkx6 function, MiPs exhibit normal early expression of islet1, which is required for motoneuron formation; however, they fail to maintain islet1 expression. Misexpression of islet1 RNA can compensate for loss of Nkx6 function, providing evidence that Islet1 acts downstream of Nkx6. We suggest that Nkx6 proteins regulate MiP development at least in part by maintaining the islet1 expression that is required both to promote the MiP subtype and to suppress interneuron development.
Volume 134(9)
Pages 1671-7
Published 2007-5
DOI 10.1242/dev.02826
PII dev.02826
PMID 17376808
PMC PMC2586877
MeSH Animals Homeodomain Proteins / genetics* Homeodomain Proteins / metabolism* Interneurons / cytology Interneurons / metabolism LIM-Homeodomain Proteins Motor Neurons / cytology* Motor Neurons / metabolism Transcription Factors / genetics Transcription Factors / metabolism* Zebrafish Zebrafish Proteins / genetics Zebrafish Proteins / metabolism*
IF 5.763
Times Cited 24
Zebrafish rw0 (Tg(CM-isl1:GFP))