Functional and hierarchical interactions among zebrafish vox/vent homeobox genes.
The vertebrate Vox/Vent family of transcription factors plays a crucial role in the establishment of the dorsoventral (DV) axis, by repressing organizer genes such as bozozok/dharma, goosecoid, and chordino. In Danio rerio (zebrafish), members of the vox/vent gene family (vox/vega1, vent/vega2, and ved) are thought to share expression patterns and functional properties. Bringing novel insights in the differential activity of the zebrafish vox/vent genes, we propose a critical role for the ved gene in DV patterning of vertebrate embryos. ved is not only expressed as a maternal gene, but it also appears to function as a repressor of dorsal factors involved in organizer formation. At early- and mid-gastrula stage, ved appears to be finely controlled by antagonist crosstalks in a complex regulatory network, involving gradients of bone morphogenetic protein (BMP) activity, dorsal factors, and vox/vent family members. We show that ved transcripts are ventrally restricted by BMP factors such as bmp2b, bmp7, smad5, and alk8, and by dorsal factors (chd and gsc). Alteration of ved expression in both vox and vent deletion mutants and vox and vent mRNAs-injected embryos, suggests that vox and vent function downstream of BMP signaling to negatively regulate ved expression. This inhibitory role is emphasized by a vox and vent redundant activity, compared with single gene effects.
Gilardelli
Claudio N
CN
Department of Biology, University of Milan, Milan, Italy.
Pozzoli
Ombretta
O
Sordino
Paolo
P
Matassi
Giorgio
G
Cotelli
Franco
F
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000187:drug effects; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D008845:Microinjections; D008954:Models, Biological; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D019485:Bone Morphogenetic Proteins; D016376:Oligonucleotides, Antisense; D014157:Transcription Factors; D029961:Zebrafish Proteins