A5019322305- Fungal and yeast genetics research
- Fermentation and Sensory Analysis
- Evolution and Genetic Dynamics
- Plant and animal studies
- Yeasts and Rust Fungi Studies
- Plant Reproductive Biology
- Evolutionary Game Theory and Cooperation
- Horticultural and Viticultural Research
- Plant Virus Research Studies
- Genetic Mapping and Diversity in Plants and Animals
- Wine Industry and Tourism
- Genetic diversity and population structure
- Cancer survivorship and care
- CRISPR and Genetic Engineering
- Insect and Arachnid Ecology and Behavior
- RNA and protein synthesis mechanisms
- RNA Research and Splicing
- Mathematical and Theoretical Epidemiology and Ecology Models
- Family Support in Illness
- Wheat and Barley Genetics and Pathology
- Chromosomal and Genetic Variations
- Sexual Assault and Victimization Studies
- Orthodontics and Dentofacial Orthopedics
- RNA modifications and cancer
- Mycorrhizal Fungi and Plant Interactions
Centre for Life
2019-2022
University College London
2013-2022
Max Planck Institute for Evolutionary Biology
2012-2021
Simon Fraser University
2015
BC Mental Health & Substance Use Services
2015
University of British Columbia
2011-2012
University of Houston
2002-2008
Auckland City Hospital
2001
University of Oxford
1998
John Radcliffe Hospital
1983-1998
The SUC multigene family of the single-celled yeast Saccharomyces cerevisiae is polymorphic, with genes varying both in number and activity. All encode invertase, an enzyme that secreted to digest sucrose outside cell. This communal endeavour creates potential for individual cells defect (cheat) by stealing sugar digested their neighbours without contributing themselves. We measured fitness a defector, deleted suc2 gene, relative otherwise isogenic cooperator, functional SUC2 gene....
Matings between different Saccharomyces sensu stricto yeast species produce sexually sterile hybrids, so individuals should avoid mating with other species. Any mechanism that reduces the frequency of interspecific matings will confer a selective advantage. Here we test ability two closely-related to select their own as mates and hybridisation. We set up mate choice tests, using five independently isolated pairs species, in which individual germinating spores were presented opportunity...
Abstract Complex life has arisen through a series of ‘major transitions’ in which collectives formerly autonomous individuals evolve into single, integrated organism. A key step this process is the origin higher-level evolvability, but little known about how entities originate and gain capacity to as an individual. Here we report single mutation that not only creates new level biological organization, also potentiates evolvability. Disrupting transcription factor ACE2 Saccharomyces...
Different species are usually thought to have specific adaptations, which allow them occupy different ecological niches. But recent neutral ecology theory suggests that diversity can simply be the result of random sampling, due finite population sizes and limited dispersal. Neutral models predict not necessarily adapted niches, but functionally equivalent across a range habitats. Here, we evaluate Saccharomyces cerevisiae, one most important microbial in human history. The artificial...
We hypothesised that patients with advanced disease or a cancer type has poor prognosis may be more likely to report anxiety and depressive symptoms after diagnosis; younger age female gender moderate these effects. Patients (n=3850) were consecutively assessed PSSCAN, standardised, validated tool, at two large centres between 2004 2009. Female reported (P=0.003 P<0.001) compared men healthy comparison group. Older was associated fewer (P=0.033 (P<0.001), but this not true for lung cancer....
Is a group best off if everyone co-operates? Theory often considers this to be so (e.g. the "conspiracy of doves"), understanding underpinning social and economic policy. We observe, however, that after competition between "cheat" "co-operator" strains yeast, population fitness is maximized under co-existence. To address whether might just peculiarity our experimental system or result with broader applicability, we assemble, benchmark, dissect, test systems model. This reveals conditions...
The resilience of populations to rapid environmental degradation is a major concern for biodiversity conservation. When environments deteriorate lethal levels, species must evolve adapt the new conditions avoid extinction. Here, we test hypothesis that evolutionary rescue may be enabled by hybridization, because hybridization increases genetic variability. Using experimental evolution, show interspecific hybrid Saccharomyces yeast grow in more highly degraded than intraspecific and parental...
Yeasts are ubiquitous in temperate forests. While this broad habitat is well-defined, the yeasts inhabiting it and their life cycles, niches, contributions to ecosystem functioning less understood. present on nearly all sampled substrates forests worldwide. They associate with soils, macroorganisms, other habitats no doubt contribute broader ecosystem-wide processes. Researchers have gathered information leading hypotheses about yeasts' niches cycles based physiological observations...
Most models of speciation require gradual change and geographic or ecological isolation for new species to arise. Homoploid hybrid occurred readily between Saccharomyces cerevisiae paradoxus . Hybrids had high self-fertility (about 82%), low fertility when backcrossed either parental 7.5%), vigorous growth under different thermal environments that favored one the other species. Extensive karyotypic changes (tetrasomy) were observed in hybrids, although genic incompatibilities accounted 50%...
Models of sexual selection predict that females use ornament size to evaluate male condition. It has also been suggested asymmetry provides with accurate information about To test these ideas we experimentally manipulated condition in the stalk–eyed fly, Cyrtodiopsis dalmanni, by varying amount food available developing larvae. Males this species have greatly exaggerated eyestalk length and prefer mate males wider eyespans. Our experiments show ornaments (eyestalks) display a...
The performance of hybrids relative to their parents is an important factor in speciation research. We measured the growth 46 Saccharomyces yeast F1 interspecific and intraspecific hybrids, each parents, pairwise competition assays. found that a hybrid average its measure mid-parent heterosis, correlated with difference parental hybrid, phenotypic divergence, which consistent simple complementation low fitness alleles one parent by high other. Interspecific showed stronger heterosis than...
Abstract The cause of reproductive isolation between biological species is a major issue in the field biology. Most explanations hybrid sterility require either genetic incompatibilities nascent or gross physical imbalances their chromosomes, such as rearrangements ploidy changes. An alternative possibility that genomes become incompatible at molecular level, dependent on interactions primary DNA sequences. mismatch repair system has previously been shown to contribute established yeast by...
Hybrid sterility is thought to be due deleterious epistatic interactions between genes from different species. Here we demonstrate that dominant genic incompatibility does not contribute in hybrids Saccharomyces cerevisiae and five closely related Sterile diploids were made fertile by genome doubling produce hybrid tetraploids. Based on these previous results, conclude neither nor classical chromosomal speciation models apply.
Genome-wide sequence divergence between populations can cause hybrid sterility through the action of anti-recombination system, which rejects crossover repair double strand breaks nonidentical sequences. Because crossovers are necessary to ensure proper segregation homologous chromosomes during meiosis, reduced recombination rate in hybrids result high levels nondisjunction and therefore low gamete viability. Hybrid interspecific crosses Saccharomyces yeasts is known be associated with such...
The fundamental principle underlying sexual selection theory is that an allele conferring advantage in the competition for mates will spread through a population. Remarkably, this has never been demonstrated empirically. We have developed experimental system using yeast testing genetic models of selection. Yeast signal to potential partners by producing attractive pheromone; stronger signallers are preferred as mates. tested effect high and low levels on evolution gene determining strength...
The ability of rare types to invade populations is important for the maintenance diversity and spread beneficial variants. Spatial structure promotes strategies interference competition by limiting diffusion toxins resources, often allowing competitors when rare. Consistent with previous results in other microbial systems, toxin production Saccharomyces cerevisiae advantageous spatially structured, high-density environments, but not unstructured environments. However, at low density...
The natural history of the model yeast Saccharomyces cerevisiae is poorly understood and confounded by domestication. In nature, S. its undomesticated relative paradoxus are usually found on bark oak trees, a habitat very different from wine or other human fermentations. It unclear whether trees really primary for wild yeast, this apparent association due to biased sampling. We use culturing high-throughput environmental sequencing show that rare member microbial community. find can grow...
Abstract Evidence is rapidly accumulating that hybridization generates adaptive variation. Transgressive segregation in hybrids could promote the colonization of new environments. Here, we use an assay to select hybrid genotypes can proliferate environmental conditions beyond tolerated by their parents, and directly compete them against parental habitats across clines. We made 45 different swarms crossing yeast strains (both Saccharomyces cerevisiae S. paradoxus ) with genetic phenotypic...
Abstract Hybridization between species can either promote or impede adaptation. But we know very little about the genetic basis of hybrid fitness, especially in nondomesticated organisms, and when populations are facing environmental stress. We made genetically variable F2 from two divergent Saccharomyces yeast species. exposed to ten toxins sequenced most resilient hybrids on low coverage using ddRADseq investigate four aspects their genomes: 1) hybridity, 2) interspecific heterozygosity,...