Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2000-3-9
pubmed:databankReference
pubmed:abstractText
Recent studies in mouse suggest that the extraembryonic endoderm has an important role in early embryonic patterning [1]. To analyze whether similar mechanisms operate in other vertebrates, we cloned the zebrafish homologue of Hex, a homeobox gene that is expressed asymmetrically in the mouse visceral endoderm [2]. Early expression of zebrafish hex is restricted to the dorsal portion of the yolk syncytial layer (YSL), an extraembryonic tissue. By the onset of gastrulation, hex is expressed in the entire dorsal half of the YSL, which directly underlies the cells fated to form the neural plate. We show that hex expression is initially regulated by the maternal Wnt pathway and later by a Bmp-mediated pathway. Overexpression experiments of wild-type and chimeric Hex constructs indicate that Hex functions as a transcriptional repressor and its overexpression led to the downregulation of bmp2b and wnt8 expression and the expansion of chordin expression. These findings provide further evidence that the zebrafish YSL is the functional equivalent of the mouse visceral endoderm and that extraembryonic structures may regulate early embryonic patterning in many vertebrates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0960-9822
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1131-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10531010-Animals, pubmed-meshheading:10531010-Body Patterning, pubmed-meshheading:10531010-Bone Morphogenetic Proteins, pubmed-meshheading:10531010-Embryo, Nonmammalian, pubmed-meshheading:10531010-Embryonic Induction, pubmed-meshheading:10531010-Endoderm, pubmed-meshheading:10531010-Gene Expression Regulation, Developmental, pubmed-meshheading:10531010-Homeodomain Proteins, pubmed-meshheading:10531010-Mice, pubmed-meshheading:10531010-Molecular Sequence Data, pubmed-meshheading:10531010-Proto-Oncogene Proteins, pubmed-meshheading:10531010-Repressor Proteins, pubmed-meshheading:10531010-Time Factors, pubmed-meshheading:10531010-Transcription Factors, pubmed-meshheading:10531010-Wnt Proteins, pubmed-meshheading:10531010-Yolk Sac, pubmed-meshheading:10531010-Zebrafish, pubmed-meshheading:10531010-Zebrafish Proteins
pubmed:year
1999
pubmed:articleTitle
A role for the extraembryonic yolk syncytial layer in patterning the zebrafish embryo suggested by properties of the hex gene.
pubmed:affiliation
Department of Biochemistry and Biophysics University of California at San Francisco San Francisco, California, 94143-0448, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't