Figure 3

Lineage scenarios for a mutation that fall in a region of heterozygous amplification. In scenario A ₁ , the mutation (yellow star) occurred before the amplification, which doubled the mutation-bearing chromosome (shown in green). The three illustrated populations have fractions of r₀, r₁ and r₂, which sum up to 1. A ₂ is similar to A ₁ , except that the un-mutated chromosome (in orange) was doubled. For scenario B, the amplification happened first, and the mutation occurred either on the amplified (B ₁ ) or the unamplified (B ₂ ) allele. For scenario C, the mutation and the sCNA occurred on independent lineages, and the amplification affects either the same (C ₁ ) or the opposite chromosome (C ₂ ) as the mutation. Blue arrow: mutation occurrence; red arrow: sCNA occurrence.