Table 1.

Components of the Wnt pathway and their role in cardiovascular development

Gene	Species	Pathway	Phenotype	References
Wnt ligands
Wnt2	Mouse	Canonical	Placental vascular failure, inflow tract   development (E. Morrisey, unpublished observations)	[49]
Wnt5a	Mouse	Noncanonical	Outflow tract septation	[45, 59]
Wnt7a	Mouse	Canonical	Cerebral vascular development (with Wnt7b)	[14, 66]
Wnt7b	Mouse	Canonical	Pulmonary vascular smooth muscle development,   cerebral vascular development (with Wnt7a)	[13, 14, 62, 66, 86]
Wnt9a	Mouse	Unknown	Epicardial development	[46]
Wnt11	Mouse, zebra fish,   Xenopus	Noncanonical	Outflow tract development, cardiac   myocyte differentiation	[15, 17, 60, 69, 91]
Wnt receptors
Fzd4	Mouse	Unknown	Retinal vascular development (with norrin)	[70, 88]
Fzd5	Mouse	Unknown	Placental vascular development	[21]
Norrin	Mouse, human	Canonical	Retinal vascular development (with Fzd4)	[88]
Lrp5	Mouse, human	Canonical	Retinal vascular development	[24, 70, 86]
Lrp6	Mouse	Canonical	Vascular smooth muscle proliferation and survival	[85]
Signaling components
Beta-catenin	Mouse, zebra fish	Canonical	SHF progenitor proliferation, cardiac valve   development, adult hypertrophic growth	[2, 10, 12, 20, 29, 37– 39,   50, 51, 76, 79, 84]
Dvl1	Mouse	Unknown	Myofibroblast proliferation	[9]
Dvl2	Mouse	Unknown	Outflow tract development	[18]
Gsk3β	Mouse	Canonical	Adult cardiac hypertrophic growth	[10, 72, 73]
Vangl2	Mouse	Noncanonical	Outflow tract development	[54]
Apc	Zebra fish	Canonical	Cardiac valve development	[20]

SHF second heart field