Mutations in six DxDxDG calcium binding motifs (D499/501/503A, D512/514/516A, D571/573/575A, D632/634/636A, D655/557/659A, and D668/670/672A) within the T3R domains of mouse Thbs4 are under the control of a minimally active mouse alpha myosin heavy chain (Myh6) promoter fused to seven copies of the tetracycline-responsive promoter element (tetO). To make the Myh6 promoter minimally active, three GATA sites and two thyroid-like response elements are ablated. (J:264241)