combining ability, gene action, heritability and other genetic parameters in bread wheat under drought stress condition were evaluated using half diallel design. nine wheat cultivars and 36 derived f1 assessed in a randomized complete block design with three replications in shahid bahonar university of kerman research field in 2013. evaluated genotypes showed high diversity for all traits. gene...

Since Bateson's discovery that genes can suppress the phenotypic effects of other genes, gene interactions-called epistasis-have been the topic of a vast research effort. Systems and developmental biologists study epistasis to understand the genotype-phenotype map, whereas evolutionary biologists recognize the fundamental importance of epistasis for evolution. Depending on its form, epistasis m...

Epistasis between mutations can make adaptation contingent on evolutionary history. Yet despite widespread ‘microscopic’ epistasis the involved, microbial evolution experiments show consistent patterns of fitness increase replicate lines. Recent work shows that this consistency is driven in part by global diminishing-returns and increasing-costs epistasis, which systematically less beneficial (...

Epistasis describes an interaction between the effects of loci. We included epistasis in quantitative trait locus (QTL) mapping of growth at a series of ages in a cross of a Chinese pig breed, Erhualian, with a commercial line, White Duroc. Erhualian pigs have much lower growth rates than White Duroc. We improved a method for genomewide testing of epistasis and present a clear analysis workflow...

There is increasing evidence of segregating sexually antagonistic (SA) genetic variation for fitness in laboratory and wild populations, yet the conditions for the maintenance of such variation can be restrictive. Epistatic interactions between genes can contribute to the maintenance of genetic variance in fitness and we suggest that epistasis between SA genes should be pervasive. Here, we expl...

Fitness interactions between mutations, referred to as epistasis, can strongly impact evolution. For RNA viruses and retroviruses with their high mutation rates, epistasis may be particularly important to overcome fitness losses due to the accumulation of deleterious mutations and thus could influence the frequency of mutants in a viral population. As human immunodeficiency virus type 1 (HIV-1)...

Background Evolutionary adaptation is a process where a population increases its “fit” to the world it inhabits, and is often likened to climbing a hill or peak. While this process is trivial for fitness landscapes where each mutation provides an advantage (or disadvantage) to the organism that is independent of the fitness effect of a mutation on a different locus, the interaction between muta...

7 High-order epistasis has been observed in many genotype-phenotype maps. These multi-way inter8 actions could have profound implications for evolution and may be useful for dissecting complex 9 traits. Previous analyses have assumed a linear genotype-phenotype map, and then applied a linear 10 high-order epistasis model to dissect epistasis. The assumption of linearity has not been tested 11 i...

Understanding epistasis is central to biology. For instance, epistatic interactions determine the topography of the fitness landscape and affect the dynamics and determinism of adaptation. However, few empirical data are available, and comparing results is complicated by confounding variation in the system and the type of mutations used. Here, we take a systematic approach by quantifying epista...

The phenotypic effect of an allele at one genetic site may depend on alleles at other sites, a phenomenon known as epistasis. Epistasis can profoundly influence the process of evolution in populations and shape the patterns of protein divergence across species. Whereas epistasis between adaptive substitutions has been studied extensively, relatively little is known about epistasis under purifyi...