Resolution:
## Figure 1.
The log growth rates of two mutations combine additively. (a) The average effect of a double knockout (G_{11}) as a function of the effects of the single knockouts (G_{01 }and G_{10}) is G_{11 }= G_{01 }+ G_{10}. Experimental mean +/- standard deviation (blue line and blue shaded area) and prediction
of the additive null model (red line). (b) Given two mutations, there are four possible mutants with their corresponding log
growth rates (black dots). If three of the four log growth rates are known, the fourth
one can be predicted by a linear extrapolation (red plane), and epistasis can be defined
as the linear deviation from such prediction (red arrow). The magnitude of the deviation
is the same regardless of which three of four mutants are chosen.
Velenich and Gore |