Figure 6.

Twenty-eight hour lineage chase provides further evidence of neutral competition. (A) Lineage histories of different clone fates (in size and Dl⁺ cell content). Cases in dashed boxes can be accessed through different histories: for instance, a 4-cell clone with one Dl⁺ cell can originate from three consecutive asymmetric divisions (red pathway) or one asymmetric and two symmetric ones of opposing result (green pathway). All ambiguities are equivalent in terms of balance of symmetric duplication versus symmetric differentiation. (B) Two-cell clones showing the three different possible fates: symmetric duplication (two Dl⁺ cells, i–ii), asymmetric (one Dl⁺ cell, iii–iv) and symmetric differentiation (no Dl⁺ cells, v–vi). (C) Matrix indicating the number of clones scored for each given clone size and given number of Dl⁺ cells. Magenta hues represent relative frequencies of the scored events (magenta: 100%; white: 0%). Note that the majority of clones are of unambiguous lineage history (A).