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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2003-2-17
pubmed:abstractText
A conserved endothelin 1 signaling pathway patterns the jaw and other pharyngeal skeletal elements in mice, chicks and zebrafish. In zebrafish, endothelin 1 (edn1 or sucker) is required for formation of ventral cartilages and joints in the anterior pharyngeal arches of young larvae. Here we present genetic analyses in the zebrafish of two edn1 downstream targets, the bHLH transcription factor Hand2 and the homeobox transcription factor Bapx1, that mediate dorsoventral (DV) patterning in the anterior pharyngeal arches. First we show that edn1-expressing cells in the first (mandibular) and second (hyoid) pharyngeal arch primordia are located most ventrally and surrounded by hand2-expressing cells. Next we show that along the DV axis of the early first arch primordia, bapx1 is expressed in an intermediate domain, which later marks the jaw joint, and this expression requires edn1 function. bapx1 function is required for formation of the jaw joint, the joint-associated retroarticular process of Meckel's cartilage, and the retroarticular bone. Jaw joint expression of chd and gdf5 also requires bapx1 function. Similar to edn1, hand2 is required for ventral pharyngeal cartilage formation. However, the early ventral arch edn1-dependent expression of five genes (dlx3, EphA3, gsc, msxe and msxb) are all present in hand2 mutants. Further, msxe and msxb are upregulated in hand2 mutant ventral arches. Slightly later, an edn1-dependent ventral first arch expression domain of gsc is absent in hand2 mutants, providing a common downstream target of edn1 and hand2. In hand2 mutants, bapx1 expression is present at the joint region, and expanded ventrally. In addition, expression of eng2, normally restricted to first arch dorsal mesoderm, expands ventrally in hand2 and edn1 mutants. Thus, ventral pharyngeal specification involves repression of dorsal and intermediate (joint region) fates. Together our results reveal two critical edn1 effectors that pattern the vertebrate jaw: hand2 specifies ventral pharyngeal cartilage of the lower jaw and bapx1 specifies the jaw joint.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0950-1991
pubmed:author
pubmed:issnType
Print
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1353-65
pubmed:dateRevised
2011-10-26
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Two endothelin 1 effectors, hand2 and bapx1, pattern ventral pharyngeal cartilage and the jaw joint.
pubmed:affiliation
Institute of Neuroscience, 1254 University of Oregon, Eugene, OR 97403, USA. ctm@stanford.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't