PUBLICATION

The smad5 mutation somitabun blocks Bmp2b signaling during early dorsoventral patterning of the zebrafish embryo

Authors

Hild, M., Dick, A., Rauch, G.J., Meier, A., Bouwmeester, T., Haffter, P., and Hammerschmidt, M.

ID

ZDB-PUB-990507-8

Date

1999

Source

Development (Cambridge, England) 126(10): 2149-2159 (Journal)

Registered Authors

Dick, Alexander, Haffter, Pascal, Hammerschmidt, Matthias, Hild, Marc, Rauch, Gerd-Jörg

Keywords

smad5; Bmp2/4 signaling; doresoventral patterning; zebrafish

MeSH Terms

Base Sequence
Phenotype
Bone Morphogenetic Protein 4
Bone Morphogenetic Proteins/genetics
Bone Morphogenetic Proteins/metabolism*
Bone Morphogenetic Proteins/pharmacology
DNA, Complementary
DNA-Binding Proteins/genetics
DNA-Binding Proteins/metabolism*
Signal Transduction*
Body Patterning
Zebrafish Proteins
Zebrafish
Trans-Activators/genetics
Trans-Activators/metabolism*
Amino Acid Sequence
Molecular Sequence Data
Smad5 Protein
Bone Morphogenetic Protein 2
Humans
Transforming Growth Factor beta*
Genetic Linkage
Smad Proteins
Animals
Phosphoproteins/genetics
Phosphoproteins/metabolism*

(all 26)

PubMed

10207140 Full text @ Development

Abstract

Signaling by members of the TGFbeta superfamily is thought to be transduced by Smad proteins. Here, we describe a zebrafish mutant in smad5, designated somitabun (sbn). The dominant maternal and zygotic effect of the sbntc24 mutation is caused by a change in a single amino acid in the L3 loop of Smad5 protein which transforms Smad5 into an antimorphic version, inhibiting wild-type Smad5 and related Smad proteins. sbn mutant embryos are strongly dorsalized, similarly to mutants in Bmp2b, its putative upstream signal. Double mutant analyses and RNA injection experiments show that sbn and bmp2b interact and that sbn acts downstream of Bmp2b signaling to mediate Bmp2b autoregulation during early dorsoventral (D-V) pattern formation. Comparison of early marker gene expression patterns, chimera analyses and rescue experiments involving temporally controlled misexpression of bmp or smad in mutant embryos reveal three phases of D-V patterning: an early sbn- and bmp2b-independent phase when a coarse initial D-V pattern is set up, an intermediate sbn- and bmp2b-dependent phase during which the putative morphogenetic Bmp2/4 gradient is established, and a later sbn-independent phase during gastrulation when the Bmp2/4 gradient is interpreted and cell fates are specified.

Genes / Markers

Figures

Show all Figures

Expression

Gene	Fish	Conditions	Stage	Qualifier	Anatomy	Assay	Figure
bmp2b	bmp2b^ta72a/ta72a	standard conditions	Shield		blastoderm	ISH	Fig. 5
bmp2b	bmp2b^ta72a/ta72a	standard conditions	Sphere	Not Detected	presumptive dorsal mesoderm	ISH	Fig. 5
bmp2b	bmp2b^ta72a/ta72a	standard conditions	Shield		yolk syncytial layer	ISH	Fig. 5
bmp2b	smad5^dtc24/+	standard conditions	Shield		blastoderm	ISH	Fig. 5
bmp2b	smad5^dtc24/+	standard conditions	Sphere	Not Detected	presumptive dorsal mesoderm	ISH	Fig. 5
bmp2b	smad5^dtc24/+	standard conditions	Shield		yolk syncytial layer	ISH	Fig. 5
bmp2b	WT	standard conditions	Shield		blastoderm	ISH	Fig. 5
bmp2b	WT	standard conditions	Sphere	Not Detected	presumptive dorsal mesoderm	ISH	Fig. 5
bmp2b	WT	standard conditions	Shield		yolk syncytial layer	ISH	Fig. 5
smad1	WT	standard conditions	75%-epiboly to Long-pec		whole organism	NB	Fig. 2

1 - 10 of 11

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Phenotype

Fish	Conditions	Stage	Phenotype	Figure
bmp2b^ta72a/+; smad5^dtc24/+	standard conditions	Prim-25	whole organism wholly dorsalized, abnormal	Fig. 3
smad5^dtc24/+	standard conditions	Prim-25	whole organism wholly dorsalized, abnormal	Fig. 3
smad5^dtc24/+	standard conditions	Long-pec	whole organism wholly dorsalized, abnormal	Fig. 3
smad5^dtc24/dtc24	standard conditions	Long-pec	whole organism wholly dorsalized, abnormal	Fig. 3
smad5^dtc24/dtc24	standard conditions	Long-pec	whole organism wholly dorsalized, abnormal	Fig. 3
smad5^dtc24	standard conditions	Prim-5	caudal fin wholly dorsalized, abnormal	Fig. 3
smad5^dtc24	standard conditions	Long-pec	whole organism wholly dorsalized, abnormal	Fig. 3

1 - 7 of 7

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Mutations / Transgenics

Allele	Construct	Type	Affected Genomic Region
dtc24		Point Mutation	smad5
ta72a		Point Mutation	bmp2b

Human Disease / Model

Sequence Targeting Reagents

Fish

Fish
bmp2b^ta72a/+; smad5^dtc24/+
bmp2b^ta72a/ta72a
smad5^dtc24/dtc24
smad5^dtc24/dtc24
smad5^dtc24/+
smad5^dtc24/+
smad5^dtc24/+
smad5^dtc24/+
smad5^dtc24
smad5^dtc24

Antibodies

Orthology

Gene	Orthology
smad5

Engineered Foreign Genes

Mapping

Hild et al., 1999 ZDB-PUB-990507-8 PMID:10207140

The smad5 mutation somitabun blocks Bmp2b signaling during early dorsoventral patterning of the zebrafish embryo

Hild et al., 1999

ZDB-PUB-990507-8
PMID:10207140