Synthetical lethals in cellmap genetic networks

Guo: I think this is explained in the paper, van Leeuwen et al.,  "Exploring genetic suppression interactions on a global scale", Science (2016), 354:aag0839.

This paper mentioned synthetic letality but did not explicitly define if it is a positive or negative interaction. However, I think genetic interactions derived by synthetic lethality should be negative effect. As the positive effect indicates that if mutation of gene A causes a reduced fitness, the double mutation of A and B restored the fitness, and hence gene B is a genetic suppressor of gene A.

I cannot find it on the CellMap website. However, from the NxN database and the fitness data I identified 2191 negative GI's , in which the double mutant fitness (DMF) is lower than 0.1. You may use different criterion, e.g., 159 interactions with DMF <= 0; or 193 with DMF <= 0.01, etc.

See the attached csv file (ranked by the DMF). 

According to DCell paper, Ma et al, synthetic leathal is an example of negative genetic interaction.  see its Figure 3, negative interaction between pmt1D and ire1D. 

synthetical lethal interactions

Byte-5:originals hqin$ grep synthe PPI_221205.tab | wc -l

    1062

Byte-5:originals hqin$ pwd

/Users/hqin/data/interaction/mips-yeast/originals

Byte:genetic-interaction hqin$ pwd

/Users/hqin/data/Sce.shanghai/mips/genetic-interaction

Byte:genetic-interaction hqin$ wc -l synthetic.lethals.tab

     441 synthetic.lethals.tab

Synthetic lethal interaction and survival functions

I am really excited by this formula, which means that survivorships of single deletions can be used to infer gene interaction of the two genes involved. 

June 25, 2013 Correction: 
I made a mistake here. The final simplication of $S_dX / S_dY$ was mistakenly used of mortality rates. Instead, I should use the survival functions directly. 
$t_0$ should be the denominator of $t$ inside of the parenthesis. 

Synthetical lethal pairs is equivalent to parallel components

The network survivor function S(t) is based on network structure function (see Leemis09, example 3.9 figure 3.9 on page72). Mortality rate (hazard rate) can be found by definition:  h(t) = -S' / dS .

$S_a$ and $S_b$ follow the Weibull model in earlier aging based on GG01.