Figure 3.

Gro and Mtv interact in vivo and in vitro. (A,D) Cuticle preparations of gro¹/gro^E48 (A) and mtv⁶/+;gro¹/gro^E48 (D) adult wings. Note in (D) ectopic veins L2 and L3 (L2^*, L3^*), and the enlargement of the anterior compartment; compartments a and p are indicated. (B,C,E,F) gro¹/gro^E48 (B,C) and mtv⁶/+;gro¹/gro^E48 (E,F) wing discs labelled to visualize expression of hh messenger RNA (purple; B,E), Araucan (Ara, blue; C,F) and Engrailed (red; C,F). (G) Co-immunoprecipitation (IP) of Myc-tagged Mtv (Mtv–Myc) by binding to Gro. S2 cells were co-transfected to express Gro and Mtv–Myc or transfected to express Gro or Mtv–Myc alone; empty vector was co-transfected as control in the latter cases. Right panels show 1/30 of Gro and Mtv–Myc proteins in cell lysates; cell lysates were immunoprecipitated with Gro antibody (left). Mtv–Myc was co-immunopreciptitated in significant amounts in cells co-transfected with Gro and Mtv–Myc (lane 1). Mtv–Myc was also co-immunopreciptitated in lesser amount in cells transfected with Mtv–Myc alone (lane 3) as a result of the endogenous Gro present in S2 cells (lanes 11, 12, 15 and 16). In the absence of Gro antibody, Mtv–Myc was not co-immunopreciptitated (data not shown). a, anterior; Gro, Groucho; Hh, hedgehog; Mtv, master of thickveins; p, posterior.