Skip to main content


Fig. 1 | BMC Biology

Fig. 1

From: A role for actomyosin contractility in Notch signaling

Fig. 1

Myosin II activity modulates the Notch response in notum epithelial cells. (a) The Notch reporter NsfGFP is visible in epithelial cell neighbors adjacent to SOP (1N) and in epithelial cell neighbors at least one cell diameter away from any SOP cell (2N). Neur-mRFP (neuralized H2BmRFP) is expressed to label SOP cell nucleus, scale bar = 10 μm. (b) Cartoon model of adjacent Notch signaling via lateral cell-cell contacts and protrusions (1 N) vs cells signaling via basal protrusion contacts alone (2 N). (cf) Notch response (mean ± SEM) in wild-type cells (c) adjacent or (e) distant to SOP cells expressing UAS-spaghetti squashAA (sqhAA; blue) or UAS-LifeActRuby (black) under the neur-GAL4 driver. (d, f) Mean ± SEM linear regression slopes for data averaged in (c, e). ***, p ≤ 0.001 by unpaired t test. Rate (y-axis) represents change in NsfGFP fluorescence per unit time (min). (gi) Notch response in tissue where both SOP and epithelial cells express UAS-spaghetti squashAA under the pnr-GAL4 driver. Internal controls were measured outside the pnr domain. Expression of spaghetti squashAA does not affect NsfGFP levels (mean ± SEM) in (g) adjacent but does decrease NsfGFP in (h) distant cells compared to internal controls, and only decreases the rate of Notch response in distant cells (i, mean ± SEM). ***, p ≤ 0.001; ns, not significant by unpaired t test. (n) = total number of nuclei measured, N = 3 nota analyzed per genotype. (j) Images of heterogeneous cell culture to measure synthetic Notch response to myosin II activity. Cells in green express ligand, those in red express receptor. (k) Relative levels of synNotch activation (detected via luciferase assay) in response to increasing concentrations of Y-27632. Mean ± SEM, *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, by ANOVA with multiple comparisons. (l) Relative levels of synNotch activation (detected via luciferase assay) in response to siRNA against zipper (orange) or spaghetti squash (blue), in the presence of DMSO. Plus sign indicates transfection with siRNA; minus sign indicates transfection with control siRNA targeting the white gene. Mean ± SEM for 4 experimental repeats shown. See also Additional file 1: Figure S1

Back to article page