Xiang Zhang: Efficient Algorithms for Detecting Genetic Interactions in Genome-Wide Association Study. (Under the direction of Wei Wang.) Genome-wide association study (GWAS) aims to find genetic factors underlying complex phenotypic traits, for which epistasis or gene-gene interaction detection is often preferred over a single-locus approach. However, the computational burden has been a major ...

The genetic architecture of a phenotype consists of the genes, the interactions among them (epistasis), and the interactions among genes and environments (G · E) that affect the phenotype’s expression (Wade et al., 2001). For a phenotype with a ‘complex’ genetic architecture, epistasis and G · E play significant roles as opposed to a phenotype with a ‘simple’ architecture, in which interactions...

Epistatic interactions between residues determine a protein's adaptability and shape its evolutionary trajectory. When a protein experiences a changed environment, it is under strong selection to find a peak in the new fitness landscape. It has been shown that strong selection increases epistatic interactions as well as the ruggedness of the fitness landscape, but little is known about how the ...

Approaches to gene interactions based on sign epistasis have been highly influential in recent time. Sign epistasis is useful for relating local and global properties of fitness landscapes, as well as for analyzing evolutionary trajectories and constraints. The geometric theory of gene interactions, on the other hand, provides complete information on interactions in terms of minimal dependence ...

Epistasis contributes significantly to intrapopulation variation in floral morphology, development time, and male fitness components of Mimulus guttatus. This is demonstrated with a replicated line-cross experiment involving slightly over 7000 plants. The line-cross methodology is based on estimates for means. It thus has greater power than the variance partitioning approaches historically used...

Fitness costs associated with resistance or virulence genes are thought to play a key role in determining the dynamics of gene-for-gene (GFG) host-parasite coevolution. However, the nature of interactions between fitness effects of multiple resistance or virulence genes (epistasis) has received less attention. To examine effects of the functional form of epistasis on the dynamics of GFG host-pa...