Fig. 4.

Analysis of Hox/Pbx/Meis binding sites in the intron 2 regulatory region of Tbx5. (A) Tbx5 reporter constructs in the BGZA vector used in mouse transgenesis. Blue squares, putative Hox binding sites; green squares, Hox/Meis binding sites; red squares, Pbx/Meis binding sites; yellow squares, Hox/Pbx binding sites; and grey square, a putative Tbx5 binding site. To the right is shown the number of embryos showing forelimb expression out of the total number of transgenic embryos recovered. (B-D) Dorsal views of E9.5 forelimb regions showing representative β-galactosidase staining for the intron2 MscI (B), MscI(b) (C) and Hbs3-6 (Hox3-6) (D) constructs.