directional epistasis
Sanjuán R & Nebot MR 2008 A network model for the correlation between epistasis and genomic complexity. PLoS ONE 3:e2663.
- in simpler genomes epistasis is antagonistic on average
- a transition towards synergistic epistasis occurs in more complex genomes
- in small networks with multifunctional nodes, lack of redundancy, and absence of alternative pathways, epistasis is antagonistic on average
- lack of multi-functionality, high connectivity, and redundancy favor synergistic epistasis
- epistasis is a covariate of mutational robustness
- in less robust networks it tends to be antagonistic
- in more robust networks it tends to be synergistic
- network features associated with antagonistic epistasis are typically found in simple genomes
- the features associated with synergistic epistasis are more extensively exploited by higher eukaryotes
