Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-9-25
pubmed:abstractText
The synchronized contraction of myocytes in cardiac muscle requires the structural and functional integrity of the gap junctions present between these cells. Gap junctions are clusters of intercellular channels formed by transmembrane proteins of the connexin (Cx) family. Products of several Cx genes have been identified in the mammalian heart (eg, Cx45, Cx43, Cx40, and Cx37), and their expression was shown to be regulated during the development of the myocardium. Cx43, Cx40, and Cx45 are components of myocyte gap junctions, and it has also been demonstrated that Cx40 was expressed in the endothelial cells of the blood vessels. The aim of the present work was to investigate the expression and regulation of Cx40, Cx43, and Cx37 during the early stages of mouse heart maturation, between 8.5 days post coitum (dpc), when the first rhythmic contractions appear, and 14.5 dpc, when the four-chambered heart is almost completed. At 8.5 dpc, only the reverse-transcriptase polymerase chain reaction technique has allowed identification of Cx43, Cx40, and Cx37 gene transcripts in mouse heart, suggesting a very low activity level of these genes. From 9.5 dpc, all three transcripts became detectable in whole-mount in situ-hybridized embryos, and the most obvious result was the labeling of the vascular system with Cx40 and Cx37 anti-sense riboprobes. Cx40 and Cx37 gene products (transcript and/or protein) were demonstrated to be expressed in the vascular endothelial cells at all stages examined. By contrast, only Cx37 gene products were found in the endothelial cells of the endocardium. In heart, Cx37 was expressed exclusively in these cells, which rules out any direct involvement of this Cx in the propagation of electrical activity between myocytes and the synchronization of contractions. Between 9.5 and 11.5 dpc, Cx40 gene activation in myocytes was demonstrated to proceed according to a caudorostral gradient involving first the primitive atrium and the common ventricular chamber (9.5 dpc) and then the right ventricle (11.5 dpc). During this period of heart morphogenesis, there is clearly a temporary and asymmetrical regionalization of the Cx40 gene expression that is superimposed on the functional regionalization. In addition, comparison of Cx40 and Cx43 distribution at the above developmental stages has shown that these Cxs have overlapping (left ventricle) or complementary (atrial tissue and right ventricle) expression patterns.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:volume
81
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
423-37
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:9285645-Amino Acid Sequence, pubmed-meshheading:9285645-Animals, pubmed-meshheading:9285645-Antibodies, pubmed-meshheading:9285645-Base Sequence, pubmed-meshheading:9285645-Cardiovascular System, pubmed-meshheading:9285645-Connexin 43, pubmed-meshheading:9285645-Connexins, pubmed-meshheading:9285645-DNA Primers, pubmed-meshheading:9285645-Endocardium, pubmed-meshheading:9285645-Endothelium, Vascular, pubmed-meshheading:9285645-Fetal Heart, pubmed-meshheading:9285645-Gene Expression Regulation, Developmental, pubmed-meshheading:9285645-Gestational Age, pubmed-meshheading:9285645-HeLa Cells, pubmed-meshheading:9285645-Humans, pubmed-meshheading:9285645-Immunohistochemistry, pubmed-meshheading:9285645-In Situ Hybridization, pubmed-meshheading:9285645-Mice, pubmed-meshheading:9285645-Molecular Sequence Data, pubmed-meshheading:9285645-Peptide Fragments, pubmed-meshheading:9285645-Polymerase Chain Reaction, pubmed-meshheading:9285645-Transcriptional Activation, pubmed-meshheading:9285645-Transfection
pubmed:year
1997
pubmed:articleTitle
Expression pattern of connexin gene products at the early developmental stages of the mouse cardiovascular system.
pubmed:affiliation
Laboratoire de Génétique et Physiologie du Développement, UMR C9943,Institut de Biologie du Développement de Marseille, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't