Figure 5. Rescue of medio-apical Myo-II by sna-like mechanical pulses is Fog-dependent.
(a) Myo-II apical accumulation, followed by mesoderm invagination in the WT, all of which are impaired in sna RNAi-injected embryos (N=6 in each case, P=2 × 10−3, exact Fisher test). (b) Apical accumulation of Myo-II and mesoderm invagination after the initiation of magnetic stimulation of sna-dependent pulsations in snaRNAi-injected embryos (Myo-II in green, UML in red). Representative of n=6 of the N=6 sna RNAi embryos (P=2 × 10−3, exact Fisher test, Myo-II apical accumulation (n=6), full invagination (n=4), partial invagination (n=0)). (c) Sqh-GFP UML-loaded embryos injected with Sna RNAi and Fog RNAi and positioned close to the micro-magnet array, the ensemble being submitted to a magnetic field that is pulsed at a rate that mimics the rate of sna-dependent pulsations. Representative of n=7 of N=8 embryos (P=5 × 10−3, exact Fisher test). The micro-magnet array was removed after 336 s, so as to image the mesoderm directly above the individual micro-magnets. Scale bars, 10 μm.