Origin and early differentiation of the sinus node in the mouse embryo heart.
D000375:Aging; D000818:Animals; D002196:Capillaries; D002454:Cell Differentiation; D004622:Embryo, Mammalian / Q000166:cytology*; D051379:Mice; D009206:Myocardium / Q000166:cytology*; D012849:Sinoatrial Node / Q000166:cytology* / Q000648:ultrastructure