Fig. 1. Vn-expressing clones in vn mutant discs. (A-D) vn– discs containing clones ectopically expressing Vn, monitored for the expression of Ap (red in middle panels) and mirr-lacZ (red in right panels). Clones were induced during the first instar and are marked by absence of GFP expression (green). (A) vn– disc containing multiple Vn-expressing clones. The size and shape of the disc are close to normal, as are the patterns of Ap and mirr-lacZ expression. The inset shows a vn mutant disc at the same magnification. (B) vn– disc containing a single dorsolaterally positioned Vn-expressing clone (arrow). The clone is associated with a long-range, non-autonomous rescue of Ap expression, but only a short-range rescue of mirr-lacZ expression in a restricted lateral region of the presumptive wing hinge where it is normally expressed. The notum primordium is absent. (C) vn– disc containing a laterally positioned clone of Vn-expressing cells (arrow). Some rescue of growth is observed, which is associated with the induction of a non-contiguous patch of Ap-expressing cells that form an abnormally small D compartment. As in (B), mirr-lacZ expression is rescued at short-range in a lateral region of the wing hinge and the notum primordium is absent. A small Vn-expressing clone is also present in the extreme dorsoproximal region of the disc. (D) vn– disc containing a single large clone within prospective notal territory. Note that both the size and shape of the disc appear almost normal, as do the patterns of Ap and mirr-lacZ expression.
