Knockdown of MBS inhibits contractile pulses. Time-lapse images are from a MBS-shRNA embryo expressing Memb::Cherry (magenta) and sqh::GFP (green). Images represent a maximum intensity Z projection of apical sqh::GFP and a single apical slice of Gap43::mCherry. Image stacks were acquired on a laser-scanning confocal microscope (LSM 710; Carl Zeiss) at a time interval of 6.8 s per stack.