PUBLICATION

Zebrafish tbx-c functions during formation of midline structures

Authors

Dheen, T., Sleptsova-Friedrich, I., Xu, Y., Clark, M., Lehrach, H., Gong, Z., and Korzh, V.

ID

ZDB-PUB-990525-5

Date

1999

Source

Development (Cambridge, England) 126(12): 2703-2713 (Journal)

Registered Authors

Clark, Matthew D., Dheen, S. Thameem, Gong, Zhiyuan, Korzh, Vladimir, Lehrach, Hans, Sleptsova-Freidrich, Inna, Xu, Yanfei

Keywords

T-box gene; notochord; somite; chordoneural hinge; motor neuron; overexpression; dominant-negative; myoD; shh; ntl; flh; islet1; tbx6; spt; animal cap

MeSH Terms

Gene Expression Regulation, Developmental
Amino Acid Sequence
Homeodomain Proteins/genetics
Homeodomain Proteins/metabolism
Embryology/methods
Zebrafish/embryology*
Zebrafish/genetics*
Fetal Proteins/genetics
Fetal Proteins/metabolism
DNA-Binding Proteins/genetics*
DNA-Binding Proteins/metabolism
Molecular Sequence Data
Animals
Motor Neurons/metabolism
T-Box Domain Proteins*
Embryo, Nonmammalian
Zebrafish Proteins*
Mesoderm/metabolism
Nerve Tissue Proteins/genetics
Transcription Factors/genetics*
Transcription Factors/metabolism
Sequence Analysis

(all 22)

PubMed

10331981 Full text @ Development

Abstract

Several genes containing the conserved T-box region in invertebrates and vertebrates have been reported recently. Here, we describe three novel members of the T-box gene family in zebrafish. One of these genes, tbx-c, is studied in detail. It is expressed in the axial mesoderm, notably, in the notochordal precursor cells immediately before formation of the notochord and in the chordoneural hinge of the tail bud, after the notochord is formed. In addition, its expression is detected in the ventral forebrain, sensory neurons, fin buds and excretory system. The expression pattern of tbx-c differs from that of the other two related genes, tbx-a and tbx-b. The developmental role of tbx-c has been analysed by overexpression of the full-length tbx-c mRNA and a truncated form of tbx-c mRNA, which encodes the dominant-negative Tbx-c. Overexpression of tbx-c causes expansion of the midline mesoderm and formation of ectopic midline structures at the expense of lateral mesodermal cells. In dominant-negative experiments, the midline mesoderm is reduced with the expansion of lateral mesoderm to the midline. These results suggest that tbx-c plays a role in formation of the midline mesoderm, particularly, the notochord. Moreover, modulation of tbx-c activity alters the development of primary motor neurons. Results of in vitro analysis in zebrafish animal caps suggest that tbx-c acts downstream of early mesodermal inducers (activin and ntl) and reveal an autoregulatory feedback loop between ntl and tbx-c. These data and analysis of midline (ntl-/- and flh-/-) and lateral mesoderm (spt-/-) mutants suggest that tbx-c may function during formation of the notochord.

Genes / Markers

Figures

Show all Figures

Expression

Gene	Fish	Conditions	Stage	Qualifier	Anatomy	Assay	Figure
ihhb	WT	standard conditions	1-4 somites		notochord	ISH	Fig. 6
noto	WT	standard conditions	14-19 somites to 20-25 somites		chordo neural hinge medial region	ISH	Fig. 3
noto	WT	standard conditions	14-19 somites to 20-25 somites		chordo neural hinge posterior region	ISH	Fig. 3
shha	WT	standard conditions	14-19 somites to 20-25 somites		chordo neural hinge	ISH	Fig. 3
shha	WT	standard conditions	14-19 somites to 20-25 somites		floor plate	ISH	Fig. 3
shha	WT	standard conditions	14-19 somites to 20-25 somites		notochord	ISH	Fig. 3
tbx2a	WT	standard conditions	14-19 somites to 20-25 somites		cloacal chamber	ISH	Fig. 3
tbx2b	noto^n1/n1	standard conditions	1-4 somites	Not Detected	axial mesoderm	ISH	Fig. 6
tbx2b	tbx16^b104/b104	standard conditions	10-13 somites		axial mesoderm	ISH	Fig. 6
tbx2b	tbxta^b160/b160	standard conditions	1-4 somites		axial mesoderm	ISH	Fig. 6

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Phenotype

Fish	Conditions	Stage	Phenotype	Figure
noto^n1/n1	standard conditions	1-4 somites	notochord absent, abnormal	Fig. 6
tbx16^b104/b104	standard conditions	10-13 somites	notochord increased width, abnormal	Fig. 6

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Mutations / Transgenics

Allele	Type	Affected Genomic Region
b104	Indel	tbx16
b160	Indel	tbxta
n1	Small Deletion	noto

Human Disease / Model

Sequence Targeting Reagents

Fish

Fish
noto^n1/n1
tbx16^b104/b104
tbxta^b160/b160
WT

Antibodies

Name	Type	Antigen Genes	Isotypes	Host Organism
Ab1-ta	polyclonal	tbxta		Rabbit

Orthology

Engineered Foreign Genes

Mapping

Dheen et al., 1999 ZDB-PUB-990525-5 PMID:10331981

Zebrafish tbx-c functions during formation of midline structures

Dheen et al., 1999

ZDB-PUB-990525-5
PMID:10331981