Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-8-21
pubmed:abstractText
Reciprocal interordinal crosses were made between the sea urchins Strongylocentrotus purpuratus and Lytechinus pictus. Previous research indicated that the expression of many L. pictus genes is reduced in the hybrid embryos. The S. purpuratus gene encoding the spicule matrix protein SM50 and the L. pictus gene encoding its orthologue LSM34 were both expressed at normal levels per gene copy in hybrid embryos, and in about 32 skeletogenic primary mesenchyme cells (PMCs) in hybrid and natural gastrulae. In many embryos of all crosses, 16 PMCs initially ingressed, while 32-64 PMCs were present in gastrulae. The skeletal spicules of most hybrid plutei were predominantly like those of S. purpuratus, consistent with the predominance of expression of S. purpuratus genes in hybrid embryos. The spicules of some hybrid plutei showed features characteristic of L. pictus, such as recurrent rods, branched body rod tips, or convergent ventral transverse rods; a few hybrid spicules were predominantly like those of L. pictus. Based on our observations and the literature, we propose the following. Cues from the ectodermal epithelium position the PMCs as they elaborate the initial triradiate spicules. Their orientation and outgrowth appears to be responsible for the convergence of the tips of body rods in most S. purpuratus and hybrid embryos, unlike in most L. pictus embryos. Variations among hybrid and natural embryos in skeletal branching pattern reflect differences in interpretation by PMCs of patterning cues produced by the ectodermal epithelium that probably have similar spatial distributions in the two species.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0302-766X
pubmed:author
pubmed:issnType
Print
pubmed:volume
305
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
159-67
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Skeletogenesis in sea urchin interordinal hybrid embryos.
pubmed:affiliation
Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada. brandhor@sfu.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't