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Early Myocardial Function Affects Endocardial Cushion Development in Zebrafish
- Source :
- PLoS Biology, PLoS Biology, Vol 2, Iss 5, p E129 (2004)
- Publication Year :
- 2004
- Publisher :
- Public Library of Science, 2004.
-
Abstract
- Function of the heart begins long before its formation is complete. Analyses in mouse and zebrafish have shown that myocardial function is not required for early steps of organogenesis, such as formation of the heart tube or chamber specification. However, whether myocardial function is required for later steps of cardiac development, such as endocardial cushion (EC) formation, has not been established. Recent technical advances and approaches have provided novel inroads toward the study of organogenesis, allowing us to examine the effects of both genetic and pharmacological perturbations of myocardial function on EC formation in zebrafish. To address whether myocardial function is required for EC formation, we examined silent heart (sih−/−) embryos, which lack a heartbeat due to mutation of cardiac troponin T (tnnt2), and observed that atrioventricular (AV) ECs do not form. Likewise, we determined that cushion formation is blocked in cardiofunk (cfk−/−) embryos, which exhibit cardiac dilation and no early blood flow. In order to further analyze the heart defects in cfk−/− embryos, we positionally cloned cfk and show that it encodes a novel sarcomeric actin expressed in the embryonic myocardium. The Cfks11 variant exhibits a change in a universally conserved residue (R177H). We show that in yeast this mutation negatively affects actin polymerization. Because the lack of cushion formation in sih- and cfk-mutant embryos could be due to reduced myocardial function and/or lack of blood flow, we approached this question pharmacologically and provide evidence that reduction in myocardial function is primarily responsible for the defect in cushion development. Our data demonstrate that early myocardial function is required for later steps of organogenesis and suggest that myocardial function, not endothelial shear stress, is the major epigenetic factor controlling late heart development. Based on these observations, we postulate that defects in cardiac morphogenesis may be secondary to mutations affecting early myocardial function, and that, in humans, mutations affecting embryonic myocardial function may be responsible for structural congenital heart disease.<br />Cardiac anomolies can result from very early defects in heart development. In zebrafish, such defects have been shown to be caused by a new gene called cardiofunk
- Subjects :
- Time Factors
Heart disease
TNNT2
Oligonucleotides
Molecular Biology/Structural Biology
Epigenesis, Genetic
Animals, Genetically Modified
0302 clinical medicine
Danio (Zebrafish)
Transgenes
Biology (General)
Cloning, Molecular
Zebrafish
In Situ Hybridization
Genetics
0303 health sciences
Heart development
General Neuroscience
Chromosome Mapping
Gene Expression Regulation, Developmental
Heart
Cell biology
Phenotype
General Agricultural and Biological Sciences
Research Article
Genotype
Heart Diseases
QH301-705.5
Green Fluorescent Proteins
Morphogenesis
Organogenesis
Biology
Development
Genetics/Genomics/Gene Therapy
General Biochemistry, Genetics and Molecular Biology
03 medical and health sciences
medicine
Animals
Actin
Endocardium
030304 developmental biology
General Immunology and Microbiology
Models, Genetic
Myocardium
medicine.disease
biology.organism_classification
Actins
Mutation
RNA
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- ISSN :
- 15457885 and 15449173
- Volume :
- 2
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- PLoS Biology
- Accession number :
- edsair.doi.dedup.....30fb27cfb9b669e69c4b4ebc8539f410