Automated lineaging of 13 neuroblast divisions that produce an apoptotic daughter cell.
(A) Schematic representation of an embryo at 265 mins of development showing the positions of the 13 cells (or their daughters) whose divisions were analyzed. Cells are color-coded to describe which ones divide to produce an anterior daughter (blue) or posterior daughter (red) that dies. ABaraaaap (#7), which produces a posterior daughter that dies and whose division asymmetry is affected by ham-1 loss, is labelled in yellow. (B) Asymmetry ratios of all analyzed daughter cells in wild-type (green circles) and ham-1(gm279) (red circles) embryos. The name of the apoptotic cell (e.g., ABalaappaa) is represented along the X-axis with the corresponding number of daughter cells doublet used in (A). (C) A representative division of the ABalapapa cell (#3) yielding an anterior apoptotic daughter in wild-type (upper panel) and ham-1(gm279) (lower panel) embryos. Arrows indicate the two daughters, with anterior to the left. In the ham-1(gm279) mutant embryos, the asymmetry is reversed and reduced. The plasma membrane is labeled with pie-1::PH::mCherry and the nucleus is visualized with his-72::HIS-72::GFP (REFs). Scale bars: 10 μm. (D, E) Comparison of asymmetry ratios for wild-type and ham-1(gm279) embryo to the time of chromatin compaction, a marker for apoptosis.