The contribution to an organism's phenotype from one genetic locus may depend upon the status of other loci. Such epistatic interactions among loci are now recognized as fundamental to shaping the process of adaptation in evolving populations. Although little is known about the structure of epistasis in most organisms, recent experiments with bacterial populations have concluded that antagonistic interactions abound and tend to de-accelerate the pace of adaptation over time. Here, we use the NK...
In the absence of recombination, a mutator allele can spread through a population by hitchhiking with beneficial mutations that appear in its genetic background. Theoretical studies over the past decade have shown that the survival and fixation probability of beneficial mutations can be severely reduced by population size bottlenecks. Here, we use computational modelling and evolution experiments with the yeast S. cerevisiae to examine whether population bottlenecks can affect mutator dynamics in adapting asexual populations....
Data from: Population structure of the Chagas disease vector, Triatoma infestans, at the urban-rural interfaceErica A. Foley, Camilo E. Khatchikian, Josephine Hwang, Jenny Ancca-Juárez, Katty Borrini-Mayori, Victor R. Quispe-Machaca, Michael Z. Levy & Dustin Brisson
The increasing rate of biological invasions resulting from human transport or human-mediated changes to the environment have had devastating ecologic and public health consequences. The kissing bug, Triatoma infestans, has dispersed through the Peruvian city of Arequipa. The biological invasion of this insect has resulted in a public health crisis, putting thousands of residents of this city at risk of infection by Trypanosoma cruzi and subsequent development of Chagas disease. Here we show that populations...
Data from: Genetic background and GxE interactions modulate the penetrance of a naturally occurring wing mutation in Drosophila melanogasterJoseph Lachance, Lawrence Jung & John R. True
Many genes involved in producing complex traits are incompletely penetrant. One such example is vesiculated, an X-linked gene in Drosophila melanogaster that results in wing defects. To examine the genetic architecture of a complex trait (wings containing vesicles), we placed a naturally occurring variant into multiple autosomal backgrounds and quantified penetrance and expressivity at a range of developmental temperatures. We found significant epistasis, genotype-by-environment interactions, and maternal effects. Sex and temperature effects were modulated by...
Redundancies and correlations in the responses of sensory neurons may seem to waste neural resources, but they can also carry cues about structured stimuli and may help the brain to correct for response errors. To investigate the effect of stimulus structure on redundancy in retina, we measured simultaneous responses from populations of retinal ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure; these stimuli and recordings are publicly available online....
Data from: Coevolutionary patterns and diversification of ant-fungus associations in the asexual fungus-farming ant Mycocepurus smithii in PanamaKatrin Kellner, Hermogenes Fernández-Marín, Heather D. Ishak, Ruchira Sen, Timothy A. Linksvayer & Ulrich G. Mueller
Partner fidelity through vertical symbiont transmission is thought to be the primary mechanism stabilizing cooperation in the mutualism between fungus-farming (attine) ants and their cultivated fungal symbionts. An alternate or additional mechanism could be adaptive partner or symbiont choice mediating horizontal cultivar transmission or de novo domestication of free-living fungi. Using microsatellite-genotyping for the attine ant Mycocepurus smithii and ITS rDNA-sequencing for fungal cultivars, we provide the first detailed population-genetic analysis of local ant-fungus associations...
In the classic view introduced by R. A. Fisher, a quantitative trait is encoded by many loci with small, additive effects. Recent advances in quantitative trait loci mapping have begun to elucidate the genetic architectures underlying vast numbers of phenotypes across diverse taxa, producing observations that sometimes contrast with Fisher's blueprint. Despite these considerable empirical efforts to map the genetic determinants of traits, it remains poorly understood how the genetic architecture of a trait should...
University of Pennsylvania7
The University of Texas at Austin1
Laboratoire de Physique Théorique1
University of Chicago1
Smithsonian Tropical Research Institute1
Institute of Science and Technology Austria1
Cayetano Heredia University1