Developmental functions of mouse Wnt genes Gene   Phenotype of knockout or other functions ------------------------------------------------------------------------ Wnt1   Loss of a portion of the midbrain and cerebellum    Deficiency in dorsal neural-tube derivatives, including neural-crest cells in double knockout with Wnt3a Wnt2   Placental defects Wnt3   Defects in axis formation and gastrulation    Defects in hair growth and structure Wnt3a   Defects in somite and tailbud development    Deficiency in dorsal neural-tube derivatives, including neural crest cells in double knockout with Wnt1    Loss of hippocampus Wnt4   Defects in kidney development    Defects in female development; absence of Müllerian duct, ectopic synthesis of testosterone in females    Defects in mammary gland morphogenesis Wnt5a   Truncated limbs, shortened anterior-posterior axis, reduced number of proliferating cells Wnt7a   Defects in limb polarity    Female infertility due to failure of Müllerian duct regression    Defects in uterine patterning    Defects in synapse maturation in the cerebellum Wnt7b   Placental defects Wnt10b   Inhibition of adipogenesis