Linked Life Data

12509127

Source:http://linkedlifedata.com/resource/pubmed/id/12509127

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2003-1-1
pubmed:abstractText
We discuss steps in the specification of major tissue territories of the sea urchin embryo that occur between fertilization and hatching blastula stage and the cellular interactions required to coordinate morphogenetic processes that begin after hatching. We review evidence that has led to new ideas about how this embryo is initially patterned: (1) Specification of most of the tissue territories is not direct, but proceeds gradually by progressive subdivision of broad, maternally specified domains that depend on opposing gradients in the ratios of animalizing transcription factors (ATFs) and vegetalizing (beta-catenin) transcription factors; (2) the range of maternal nuclear beta-catenin extends further than previously proposed, that is, into the animal hemisphere, where it programs many cells to adopt early aboral ectoderm characteristics; (3) cells at the extreme animal pole constitute a unique ectoderm region, lacking nuclear beta-catenin; (4) the pluripotential mesendoderm is created by the combined outputs of ATFs and nuclear beta-catenin, which initially overlap in the macromeres, and by an undefined early micromere signal; (5) later micromere signals, which activate Notch and Wnt pathways, subdivide mesendoderm into secondary mesenchyme and endoderm; and (6) oral ectoderm specification requires reprogramming early aboral ectoderm at about the hatching blastula stage. Morphogenetic processes that follow initial fate specification depend critically on continued interactions among cells in different territories. As illustrations, we discuss the regulation of (1) the ectoderm/endoderm boundary, (2) mesenchyme positioning and skeletal growth, (3) ciliated band formation, and (4) several suppressive interactions operating late in embryogenesis to limit the fates of multipotent cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0070-2153
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
159-98
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Patterning the sea urchin embryo: gene regulatory networks, signaling pathways, and cellular interactions.
pubmed:affiliation
Department of Biology, University of Rochester, Rochester, New York 14627, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review