Fig 3.

PTP61Fn is a negative regulator of growth and cellular proliferation. (A) The dpp-Gal4 driver was used to overexpress PTP61Fm versus PTP61Fn in the region of the Drosophila wing between longitudinal wing veins LIII and LIV bordered by the posterior cross vein and wing margin (area 1, yellow highlighting). The effect on growth was assessed by comparing the area of this region to the area of a region within the same wing where the dpp-Gal4 driver was not expressed, between wing veins LIV and LV (area 2, red highlighting). (B) Overexpression of PTP61Fn in the Drosophila wing significantly reduced growth (P = 0.02) compared to control (dpp-Gal4/+); however, overexpression of 1 or 2 copies of PTP61Fm had no significant effect. Results are means ± standard errors of the means (SEM) for n = 6 per genotype. (C) Immunostaining of Drosophila third-instar larval eye imaginal discs overexpressing PTP61Fn under ey-Gal4 and control flies (ey-Gal4/+), showing that PTP61Fn overexpression reduces cell proliferation as assessed by BrDu incorporation, without affecting cell differentiation (anti-elav) or apoptosis (anti-cleaved caspase-3 [cl.casp-3]).