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Mesp1 ‐nonexpressing cells contribute to the ventricular cardiac conduction system
Author(s) -
Kitajima Satoshi,
MiyagawaTomita Sachiko,
Inoue Tohru,
Kanno Jun,
Saga Yumiko
Publication year - 2006
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.20640
Subject(s) - biology , microbiology and biotechnology , population , optical mapping , atrioventricular cushions , heart development , medicine , embryonic stem cell , genetics , gene , demography , heart disease , sociology
Abstract Previous fate mapping analysis, using Cre recombinase driven by the Mesp1 locus, revealed that Mesp1 is expressed in almost all of the precursors of the cardiovascular system, including the endothelium, endocardium, myocardium, and epicardium. Mesp1 ‐nonexpressing cells were found to be restricted to the outflow tract cushion and along the interventricular septum (IVS), which is a location that is suggestive of specialized cardiac conduction system (CCS). In our current study, we examined the identity of these IVS cells by using the pattern of β‐galactosidase activity in CCS‐lacZ mice. In addition, by crossing Mesp1‐Cre and floxed GFP reporter mice with CCS‐lacZ mice, we have calculated that approximately 20% of the ventricular CCS within the IVS corresponds to Mesp1 ‐nonexpressing cells. These data suggest that the ventricular CCS is of heterocellular origin. Furthermore, we indicate a possibility that a population of the cells that contribute to the ventricular CCS might be distinguished at an early stage of development. Developmental Dynamics 235:395–402, 2006. © 2005 Wiley‐Liss, Inc.