Fig. 5. MAPK nuclear translocation and cell cycle in the developing wing. (A-D) Larval wing discs expressing hs:MG (A-C) or hs:NMG (D) after 4 hours of recovery after heat shock, showing GFP (green), bromo-deoxyuridine (BrdU, magenta in A) and phosphorylated Histone H3 (pH3, magenta in B, and white in C,D). (C,D) Confocal projections through the wing pouch of each genotype, showing each pH3-positive nuclei in the pouch. BrdU and GFP are largely restricted from non-proliferative zone in hs:MG discs (brackets in A), as are pH3 and GFP (brackets in B,C). pH3 nuclei are now observed in non-proliferative zone in hs:NMG discs (brackets in D). (E-H) Cell-sorting analysis of larval wing discs. GFP⁺ traces and numbers are in red, GFP^– are in blue. All are from wing discs expressing GFP (UAS:GFP), driven by the genetic elements indicated. Recovery times are as indicated. DNA content on the x-axis and fraction of the cells in each sample at each DNA value on the y-axis. Major DNA content peaks (2N and 4N, corresponding with G1 and G2/M) indicated. Inset tables: percentage of cells at the stages indicated (G1, S or G2/M). (I-P) Larval discs stained for expression of cell cycle and/or apoptosis markers as indicated. (I-L) Wild type. (M-P) Ectopic Msk expressed in the posterior compartment, under the control of en:GAL4 (same domain as is green in Fig. 4D). Arrowheads in I and M indicate the AP boundary. Where Msk is ectopically expressed, Cyclin E is elevated (arrow in M), stg:lacZ is elevated (arrow in N), DNA synthesis (BrdU) is slightly elevated (arrow in O) and cell apoptosis is induced (activated Caspase 3, arrow in P). Magnifications are equal in A,B; C,D; and I-P.