Cyst is required for AJ integrity. Z-projections (9.5 µm) taken from live control (n = 3) or cyst RNAi (n = 3) embryos expressing DEcad::GFP controlled by its endogenous promoter (see Videos 1 and 2). Times indicate minutes after onset of germband extension. Scale bars, 10 µm. (A) Ventral view of the ectoderm at stage 11 showing a loss of AJs in cells adjacent to the ventral midline (dashed line) in a cyst RNAi embryo. (B) Ventral ectoderm cells at the indicated time points showing the increasing fragmentation and loss of AJs in a cyst RNAi embryo. (C) Ventral ectoderm cells at the indicated time points showing clustering of AJ material in a cyst RNAi embryo (arrows).