Figure 1
Division asymmetries in unperturbed C. elegans embryos. (A) Lineage tree of early C. elegans embryogenesis (prior to gastrulation). Different lineages are color-coded, the germline is highlighted in red. (B) Representative maximum-intensity projections of image stacks taken on early C. elegans embryos (strain OD95) with the plasma membrane and chromatin stained in red and green, respectively. Scale bar: 10 μm. (C) Single two-dimensional slices taken from the image stacks shown in A. (D) The corresponding membrane segmentation shows how well details of the plasma membrane are identified. Please note: Color-coding of cell boundaries was chosen for best contrast and does not indicate correspondence to specific lineages. (E) Volumetric ratio, VR, of daughter cells emerging from the named mother cell (median of n = 10 embryos with error bars indicating the standard deviation). Color-coding of lineages like in (A). The volume-dependent level of uncertainty for each cell (grey) quantifies the apparent division asymmetry that is attributed solely to segmentation errors (see Materials and Methods for a detailed definition). As a result, cells of the P, MS, and C lineages, but also few cells of the AB lineage show significant division asymmetries that are well beyond the level of uncertainty.
