Fig. 3. Expression of ANTP and UBX/ABDA, and their relationship to DLL. (A) Antp mRNA was expressed in Mx2 and more posterior segments. (B-E) Confocal images of embryos double labeled with DLL (purple in B,C,D,D',E,E') and ANTP (green in B,D,D'') or UBX/ABDA (green in C,E,E'') (green). (B,D) ANTP expression was limited to Mx2 and anterior of first thoracic segment (T1a). Most of the DLL expression in T1 did not overlap with ANTP. Note that prominent expression of ANTP in ventral T1 corresponds to reduced expression of DLL (arrowheads in D). The dorsal cells expressing DLL are located in a different cell layer expressing ANTP but appear white in some cells because of the projection of multiple confocal sections. (C,E) UBX/ABDA expression was detected in dorsal part of T1 and in posterior segments. In the ventral region, the anterior staining border is at the posterior edge of the first thoracic segment, abutting the posterior border of ANTP. As reported in other crustaceans, millipedes and insects (Panganiban et al., 1995), UBX/ABDA are co-expressed with DLL in a large number of leg cells that appear white in the merged image. Scale bar: 100 µm.