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Downregulation of atrial markers during cardiac chamber morphogenesis is irreversible in murine embryos.
- Source :
-
Development (Cambridge, England) [Development] 1998 Nov; Vol. 125 (22), pp. 4427-38. - Publication Year :
- 1998
-
Abstract
- Vertebrate cardiogenesis is a complex process involving multiple, distinct tissue types which interact to form a four-chambered heart. Molecules have been identified whose expression patterns co-segregate with the maturation of the atrial and ventricular muscle cell lineages. It is not currently known what role intrinsic events versus external influences play in cardiac chamber morphogenesis. We developed novel, fluorescent-based, myocardial, cellular transplantation systems in order to study these questions in murine embryos and report the irreversible nature of chamber specification with respect to the downregulation of atrial myosin light chain 2 (MLC-2a) and alpha myosin heavy chain (alpha-MHC). Grafting ventricular cells into the atrial chamber does not result in upregulation of MLC-2a expression in ventricular cells. Additionally, wild-type ventricular muscle cells grafted into the wild-type background appropriately downregulate MLC-2a and alpha-MHC. Finally, grafting of RXRalpha gene-deficient ventricular muscle cells into the ventricular chambers of wild-type embryos does not rescue the persistent expression of MLC-2a, providing further evidence that ventricular chamber maturation is an early event. These studies provide a new approach for the mechanistic dissection of critical signaling events during cardiac chamber growth, maturation and morphogenesis in the mouse, and should find utility with other approaches of cellular transplantation in murine embryos. These experiments document the irreversible nature of the downregulation of atrial markers after the onset of cardiogenesis during ventricular chamber morphogenesis and temporally define the response of cardiac muscle cells to signals regulating chamber specification.
- Subjects :
- Animals
Antigens, Differentiation
Cell Transplantation
Down-Regulation
Heart Atria cytology
Heart Ventricles cytology
In Vitro Techniques
Mice
Morphogenesis
Myocardium cytology
Receptors, Retinoic Acid deficiency
Receptors, Retinoic Acid genetics
Retinoid X Receptors
Transcription Factors deficiency
Transcription Factors genetics
Heart Atria embryology
Heart Ventricles embryology
Myosin Heavy Chains biosynthesis
Myosin Light Chains biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 0950-1991
- Volume :
- 125
- Issue :
- 22
- Database :
- MEDLINE
- Journal :
- Development (Cambridge, England)
- Publication Type :
- Academic Journal
- Accession number :
- 9778502
- Full Text :
- https://doi.org/10.1242/dev.125.22.4427