Time-lapse imaging of mitoses in the trigeminal placodal ectoderm and ingressed cells. (A) (Top) Dot plot showing parallel and perpendicular cleavage planes of dividing cells in both apical and basal sides of the placodal ectoderm. (Bottom) Schematic showing the measurement of the cleavage plane orientation based on the angle made by the cleavage line at anaphase relative to the apical surface. (B) Static images from projections of 24 um z-stacks showing two differently orientated mitoses in 6 minutes of real time between metaphase and anaphase: basal parallel and the apical perpendicular, also shown in additional files 2 and 3: movies 2 and 3. They were taken at 3 minute intervals using a 20 × objective. Cleavage plane is denoted by a red dotted line and dividing cell by a white arrow. (C) Image sequence over 95 minutes of development of a 2D projection of a 45 um z-stack taken at 3 minute intervals using a 20 × objective. H2B-RFP showing nuclei and membrane-GFP showing cell morphology. Dotted lines delineate the ectoderm layer; yellow arrow points to a dividing cell just before ingression (asterisk) with its cleavage plane demarcated by yellow dotted lines; blue arrow points to a cell that divides after ingression. Note that the delaminating cell (yellow arrow and asterisk) moves from within the ectoderm to exit this tissue. See additional files 4 and 5: movies 4 and 5 for the entire sequence. Scale bar: 10 um. ecto, ectoderm; mes, mesenchyme.