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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-6-23
pubmed:databankReference
pubmed:abstractText
Echinoderms are the sister group of the chordates and hemichordates within the deuterostomes. They lack a notochord or any structures obviously homologous with it. To gain insight into developmental mechanisms important in the origin and early evolution of chordates, we investigated sea urchin homologues of chordate genes that are implicated in notochord formation, viz. Brachyury and HNF-3 beta. Here we report the pattern of expression of a sea urchin orthologue of forkhead, Hphnf3 which is present as a single copy per haploid genome. An Hphnf3 transcript of 3.0 kb was first detected at the swimming blastula stage, accumulated maximally at the gastrula and prism-embryo stages, and decreased at the pluteus-larva stage. In situ hybridization signals were found in cells of the vegetal plate of the swimming blastula. During gastrulation, intense staining was evident in the cells surrounding the blastopore, whereas weak staining was detected in the invaginating archenteron. At the prism-embryo stage, the entire archenteron stained intensely; then, at pluteus stage, the larva staining decreased in intensity. The forkhead and Brachyury genes begin to be expressed almost simultaneously in sea urchin embryos, in the vegetal plate at the late blastula stage. After the onset of gastrulation, however, Hphnf3 is expressed in the posterior part of the archenteron, whereas the Brachyury orthologue, HpTa, is expressed in the secondary mesenchyme founder cells, which occupy the anterior tip of archenteron. Hphnf3 may contribute to specification of embryonic cells as archenteron, and the role of HpTa may be directed towards specification of mesodermal founder cells. Except for the basal character of expression in endoderm and endomesoderm, these transcription factors are clearly utilized differently in chordates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0925-4773
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
163-73
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9025069-Amino Acid Sequence, pubmed-meshheading:9025069-Animals, pubmed-meshheading:9025069-Base Sequence, pubmed-meshheading:9025069-DNA-Binding Proteins, pubmed-meshheading:9025069-Drosophila, pubmed-meshheading:9025069-Embryo, Nonmammalian, pubmed-meshheading:9025069-Forkhead Transcription Factors, pubmed-meshheading:9025069-Gene Expression Regulation, Developmental, pubmed-meshheading:9025069-In Situ Hybridization, pubmed-meshheading:9025069-Mice, pubmed-meshheading:9025069-Molecular Sequence Data, pubmed-meshheading:9025069-Nuclear Proteins, pubmed-meshheading:9025069-Nucleic Acid Hybridization, pubmed-meshheading:9025069-Sea Urchins, pubmed-meshheading:9025069-Sequence Homology, Amino Acid, pubmed-meshheading:9025069-Tissue Distribution, pubmed-meshheading:9025069-Transcription Factors, pubmed-meshheading:9025069-Xenopus, pubmed-meshheading:9025069-Zebrafish
pubmed:year
1996
pubmed:articleTitle
Spatial expression of a forkhead homologue in the sea urchin embryo.
pubmed:affiliation
Department of Zoology, Graduate School of Science, Kyoto University, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't