Figure 3.

Enhanced signaling through the MEK/ERK pathway is rescued by expressing UAS-NF1 in neurons. (A) Western blot showing elevated p-ERK and p-MEK, but not p-Akt1, in NF1-deficient third instar or adult CNS compared with w¹¹¹⁸ controls. Lysates were prepared from w¹¹¹⁸ or NF1^E2 larval CNS (lanes 1,2), from w¹¹¹⁸ (lane 3), or from NF1^E2 (lanes 4,5) adult heads. The extract in lane 5 was incubated for 15 min at 37°C with 20 U of alkaline phosphatase (Roche Diagnostics) prior to electrophoresis. (B) p-ERK levels are not elevated in NF1-deficient wing discs. (C) Rescue of female pupal size (n = 30) upon expression of UAS-NF1 under the control of the ubiquitous Act5C-GAL4 or the neuronal elav-GAL4 or c23-GAL4 drivers, but not upon repo-GAL4-driven glial cell expression rescue. (*) p < 0.0001, Student t-test. (D) Pupal size rescue correlates with rescue of the third instar CNS p-ERK phenotype. (E) Third instar CNS p-ERK/ERK ratio determined by densitometric scanning of films from three experiments. (*) p < 0.05, Student t-test.