Fig. 2. Abl localization and activity. Wild-type or Abl::GFP embryos are shown. Antigens are indicated. (A) abl::GFP fusion construct. (B-D) Syncytial blastoderm. (B) Grazing-section. (C,D) Cross-sections showing apical Abl::GFP (C, arrow) and apical phosphorylated Abl (P-Abl; D, arrow). (E-H'') Cellularization. (E) Grazing-section. (F-H'') Cross-sections. (F) Abl::GFP localizes apically throughout (arrow). Nrt marks basolateral membranes. (G) Mid-cellularization; Abl::GFP is at high levels apically (arrow) and is at low levels in furrow canals (arrowhead). (H-H'') Late cellularization. Apical Abl::GFP (arrow) partially overlaps AJs (Cad). (I-J) Grazing-sections of the VF. Abl::GFP is elevated in the VF (arrows), overlapping constricting AJs (Cad). (J) P-Abl is elevated in the VF (arrow). (K-N') Cross-sections of the VF. Abl::GFP (K,L) and P-Abl (M,N) concentrate in mesoderm in the early (K-K') and late (L-L') VF (arrows), and persist apically in non-mesoderm tissue (arrowheads; L,N). (O) Apical Abl::GFP in the posterior midgut (arrow). (P) Basal Abl::GFP localization (arrow) in the late VF. (Q,R) Germband-extension. Abl::GFP (Q) and P-Abl (R) at the cell cortex. (S-S'') Abl::GFP (S, green in S'') overlaps ß-integrin (S', red in S'') in ectoderm (arrows). P-Abl, Phospho-Abl; ß-Int, ß-PS-Integrin. Scale bar: 20 µm.