Published online before print July 27, 2006, doi: 10.1161/01.RES.0000238360.33284.a0
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on June 20, 2006
Accepted on July 19, 2006
Two Distinct Pools of Mesenchyme Contribute to the Development of the Atrial Septum
Mathilda T.M. Mommersteeg ;
From the Molecular and Experimental Cardiology Group (M.T.M.M., A.T.S., F.J.d.L., M.J.B.v.d.H., V.M.C., A.F.M.M.), Academic Medical Centre, University of Amsterdam, the Netherlands; and the Cardiac Unit, Institute of Child Health (R.H.A.), University College, London, United Kingdom.
* To whom correspondence should be addressed. E-mail: a.f.moorman{at}amc.uva.nl.
Closure of the primary atrial foramen is achieved by fusion of the atrioventricular cushions with the mesenchymal cap on the leading edge of the muscular primary atrial septum. A fourth component involved is the vestibular spine, originally described by His in 1880 as an intra-cardiac continuation of the extra-cardiac mesenchyme of the dorsal mesocardium. The morphogenesis of this area is of great clinical interest, because of the high incidence of atrial and atrioventricular septal defects. Nonetheless, the origin of the participating components is largely unknown. Here we report that the primary atrial foramen is surrounded in its entirety by mesenchyme derived from endocardium. A second population of mesenchyme not derived from endocardium was observed at the caudal margin of the mesenchymal atrial cap, entirely embedded within the mesenchyme derived from endocardium and contiguous with the mesenchyme of the dorsal mesocardium. Our reconstructions show this second population does indeed take the form of a short spine, albeit that it is the right pulmonary ridge, rather than this spine, that protrudes into the atrial lumen. From the stance of morphological description, therefore, there is little thus far to substantiate the existence of an atrial spine.
This article has been cited by other articles:
 |
|
 |
|
  W. T.J. Aanhaanen, J. F. Brons, J. N. Dominguez, M. S. Rana, J. Norden, R. Airik, V. Wakker, C. de Gier-de Vries, N. A. Brown, A. Kispert, et al. The Tbx2+ Primary Myocardium of the Atrioventricular Canal Forms the Atrioventricular Node and the Base of the Left Ventricle Circ. Res., June 5, 2009; 104(11): 1267 - 1274. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. L. Sund, S. Roelker, V. Ramachandran, L. Durbin, and D. W. Benson Analysis of Ellis van Creveld syndrome gene products: implications for cardiovascular development and disease Hum. Mol. Genet., May 15, 2009; 18(10): 1813 - 1824. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. M. Goddeeris, S. Rho, A. Petiet, C. L. Davenport, G. A. Johnson, E. N. Meyers, and J. Klingensmith Intracardiac septation requires hedgehog-dependent cellular contributions from outside the heart Development, May 15, 2008; 135(10): 1887 - 1895. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. S. Snarr, J. L. O'Neal, M. R. Chintalapudi, E. E. Wirrig, A. L. Phelps, S. W. Kubalak, and A. Wessels Isl1 Expression at the Venous Pole Identifies a Novel Role for the Second Heart Field in Cardiac Development Circ. Res., November 9, 2007; 101(10): 971 - 974. [Abstract] [Full Text] [PDF]
|
|