|ZFIN ID: ZDB-PUB-980820-3|
Molecular identification of spadetail: regulation of zebrafish trunk and tail mesoderm formation by T-box genes
Griffin, K.J.P., Amacher, S.L., Kimmel, C.B., and Kimelman, D.
|Source:||Development (Cambridge, England) 125: 3379-3388 (Journal)|
|Registered Authors:||Amacher, Sharon, Griffin, Kevin, Kimelman, David, Kimmel, Charles B.|
|Keywords:||spadetail; brachyury; no tail; tbx6; posterior development; FGF; zebrafish; T-box|
Griffin, K.J.P., Amacher, S.L., Kimmel, C.B., and Kimelman, D. (1998) Molecular identification of spadetail: regulation of zebrafish trunk and tail mesoderm formation by T-box genes. Development (Cambridge, England). 125:3379-3388.
ABSTRACTInhibition of fibroblast growth factor (FGF) signaling prevents trunk and tail formation in Xenopus and zebrafish embryos. While the T-box transcription factor Brachyury (called no tail in zebrafish) is a key mediator of FGF signaling in the notochord and tail, the pathways activated by FGF in non-notochordal trunk mesoderm have been uncertain. Previous studies have shown that the spadetail gene is required for non-notochordal trunk mesoderm formation; spadetail mutant embryos have major trunk mesoderm deficiencies, but relatively normal tail and notochord development. We demonstrate here that spadetail encodes a T-box transcription factor with homologues in Xenopus and chick. Spadetail is likely to be a key mediator of FGF signaling in trunk non-notochordal mesoderm, since spadetail expression is regulated by FGF signaling. Trunk and tail development are therefore dependent upon the complementary actions of two T-box genes, spadetail and no tail. We show that the regulatory hierarchy among spadetail, no tail and a third T-box gene, tbx6, are substantially different during trunk and tail mesoderm formation, and propose a genetic model that accounts for the regional phenotypes of spadetail and no tail mutants.