DEV02395 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure 1 -

  Fig. S1. Expression of Shh in Pbx1^–/–;Pbx2^+/– (mutant) embryos. (A) Normal Shh expression in Mut cloaca (c) and notochord (nc) demonstrates that the lack of Shh is not global in the absence of Pbx1/Pbx2, and that the posterior region that gives rise to hindlimb buds develops normally. (B) Shh expression is present in mutant forelimbs, albeit reduced, suggesting that Shh absence is hindlimb specific. Proximal is towards the left; anterior is towards the top. c, cloaca; nc, notochord.

• Supplemental Figure 2 -

  Fig. S2. Pbx and Hand2 probably control Shh through parallel pathways; Shh and Pbx1/Pbx2 do not form a cross regulatory loop. (A) At E10, Pbx1 remains proximally expressed and mostly unperturbed in Hand2-deficient (KO) forelimbs (left panel), albeit a modest expansion of its expression domain is observed posteriorly. At E9.75, Pbx2 is unperturbed in Hand2 knockout forelimbs. These results indicate that Pbx1/2 are not downstream of Hand2 in limb development. (B) Shh-deficient (knockout) embryos reveal relatively unperturbed Pbx1 and Pbx2 expression at E10.75, despite their abnormal limb morphology and presence of marked apoptosis in distal domains (Chiang et al., 2001). This reported apoptosis probably causes a slight decrease of Pbx2 signal in distal limb buds. Proximal is towards the left; anterior is towards the top. FL, forelimb; HL, hindlimb.