Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-11-2
pubmed:databankReference
pubmed:abstractText
The embryonic vertebrate heart is divided into two major chambers, an anterior ventricle and a posterior atrium. Although the fundamental differences between ventricular and atrial tissues are well documented, it is not known when and how cardiac anterior-posterior (A-P) patterning occurs. The expression patterns of two zebrafish cardiac myosin genes, cardiac myosin light chain 2 (cmlc2) and ventricular myosin heavy chain (vmhc), allow us to distinguish two populations of myocardial precursors at an early stage, well before the heart tube forms. These myocardial subpopulations, which may represent the ventricular and atrial precursors, are organized in a medial-lateral pattern within the precardiac mesoderm. Our examinations of cmlc2 and vmhc expression throughout the process of heart tube assembly indicate the important role of an intermediate structure, the cardiac cone, in the conversion of this early medial-lateral pattern into the A-P pattern of the heart tube. To gain insight into the genetic regulation of heart tube assembly and patterning, we examine cmlc2 and vmhc expression in several zebrafish mutants. Analyses of mutations that cause cardia bifida demonstrate that the achievement of a proper cardiac A-P pattern does not depend upon cardiac fusion. On the other hand, cardiac fusion does not ensure the proper A-P orientation of the ventricle and atrium, as demonstrated by the heart and soul mutation, which blocks cardiac cone morphogenesis. Finally, the pandora mutation interferes with the establishment of the early medial-lateral myocardial pattern. Altogether, these data suggest new models for the mechanisms that regulate the formation of a patterned heart tube and provide an important framework for future analyses of zebrafish mutants with defects in this process.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0012-1606
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
214
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-37
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Restricted expression of cardiac myosin genes reveals regulated aspects of heart tube assembly in zebrafish.
pubmed:affiliation
Programs in Human Genetics and Developmental Biology, University of California, San Francisco, San Francisco, California, 94143-0448, USA.
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