A ryanodine receptor-dependent Ca(i)(2+) asymmetry at Hensen's node mediates avian lateral identity.
Development
; 135(19): 3271-80, 2008 Oct.
Article
en En
| MEDLINE
| ID: mdl-18755776
ABSTRACT
In mouse, the establishment of left-right (LR) asymmetry requires intracellular calcium (Ca(i)(2+)) enrichment on the left of the node. The use of Ca(i)(2+) asymmetry by other vertebrates, and its origins and relationship to other laterality effectors are largely unknown. Additionally, the architecture of Hensen's node raises doubts as to whether Ca(i)(2+) asymmetry is a broadly conserved mechanism to achieve laterality. We report here that the avian embryo uses a left-side enriched Ca(i)(2+) asymmetry across Hensen's node to govern its lateral identity. Elevated Ca(i)(2+) was first detected along the anterior node at early HH4, and its emergence and left-side enrichment by HH5 required both ryanodine receptor (RyR) activity and extracellular calcium, implicating calcium-induced calcium release (CICR) as the novel source of the Ca(i)(2+). Targeted manipulation of node Ca(i)(2+) randomized heart laterality and affected nodal expression. Bifurcation of the Ca(i)(2+) field by the emerging prechordal plate may permit the independent regulation of LR Ca(i)(2+) levels. To the left of the node, RyR/CICR and H(+)V-ATPase activity sustained elevated Ca(i)(2+). On the right, Ca(i)(2+) levels were actively repressed through the activities of H(+)K(+) ATPase and serotonin-dependent signaling, thus identifying a novel mechanism for the known effects of serotonin on laterality. Vitamin A-deficient quail have a high incidence of situs inversus hearts and had a reversed calcium asymmetry. Thus, Ca(i)(2+) asymmetry across the node represents a more broadly conserved mechanism for laterality among amniotes than had been previously believed.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Tipificación del Cuerpo
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Canal Liberador de Calcio Receptor de Rianodina
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Señalización del Calcio
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Organizadores Embrionarios
Límite:
Animals
Idioma:
En
Revista:
Development
Asunto de la revista:
BIOLOGIA
/
EMBRIOLOGIA
Año:
2008
Tipo del documento:
Article
País de afiliación:
Estados Unidos