Mutational genetic variance and the fitness optimum. Mutation and selection are ubiquitous forces in nature, but we do not understand how genetic variation produced by mutation is maintained in the presence of selection that depletes it. The recent discovery of apparent stabilising selection on traits with high levels of genetic variation provides a new approach to understanding this paradox.
A genomic approach to understanding the maintenance of genetic variation under sexual selection. Using a model Australian species, this project will dissect the linkages between DNA sequence variation, gene expression, phenotypic traits and fitness in a natural population. Data will facilitate powerful tests of evolutionary processes thought to maintain genetic variation in complex traits.
The contribution of pleiotropic mutation to genetic variation and evolution. This project aims to provide an in-depth characterization of pleiotropic effects across many traits, including fitness, in an outbred population of the fly, Drosophila serrata. The potential for one gene to affect many traits, pleiotropy, has been recognised for over 100 years. Pleiotropy is expected to underlie diverse biological phenomena, including evolution and age-related human diseases. Despite this, the contribut ....The contribution of pleiotropic mutation to genetic variation and evolution. This project aims to provide an in-depth characterization of pleiotropic effects across many traits, including fitness, in an outbred population of the fly, Drosophila serrata. The potential for one gene to affect many traits, pleiotropy, has been recognised for over 100 years. Pleiotropy is expected to underlie diverse biological phenomena, including evolution and age-related human diseases. Despite this, the contribution of pleiotropy to variation among individuals in appearance and in fitness remains poorly understood. By measuring the extent of pleiotropy and its fitness consequences, this project aims to advance understanding of how mutation and selection shape genetic variation and evolutionary potential in natural populations.Read moreRead less
Dissecting natural variation in sexually dimorphic gene expression. This project aims to understand the origins of sex differences by dissecting heritable variation in sexually dimorphic gene expression. Sexual dimorphism constitutes a large fraction of phenotypic diversity and arises mainly from sex differences in gene expression that permit males and females of a species to escape sexual conflict caused by a shared genome. The project uses multi-population quantitative genetics and allele-spec ....Dissecting natural variation in sexually dimorphic gene expression. This project aims to understand the origins of sex differences by dissecting heritable variation in sexually dimorphic gene expression. Sexual dimorphism constitutes a large fraction of phenotypic diversity and arises mainly from sex differences in gene expression that permit males and females of a species to escape sexual conflict caused by a shared genome. The project uses multi-population quantitative genetics and allele-specific expression assays to merge the studies of sex-specific local adaptation and sexually dimorphic regulatory variation. The project will help to understand how cis- and trans- regulatory factors can affect natural variation differently in males and females, shaping their phenotypic similarities and differences.Read moreRead less
Resolving genomic sexual conflicts via sexually dimorphic gene expression. Using powerful genomic technology this project aims to assess the strength of regulatory constraints between males and females and determine whether cis-regulatory mutations help to resolve them. Sex-differences in traits like morphology, behaviour and disease susceptibility often involve sex-differences in the regulation of gene expression. To achieve optimal performance, males and females must express their genes at dif ....Resolving genomic sexual conflicts via sexually dimorphic gene expression. Using powerful genomic technology this project aims to assess the strength of regulatory constraints between males and females and determine whether cis-regulatory mutations help to resolve them. Sex-differences in traits like morphology, behaviour and disease susceptibility often involve sex-differences in the regulation of gene expression. To achieve optimal performance, males and females must express their genes at different levels. Theory and data suggest that for some genes this is not possible, and that males and females could each achieve higher performance if gene regulation became genetically uncoupled between them. It has been suggested that cis-regulatory mutations may be important for resolving regulatory incompatibilities within the genome.Read moreRead less
Discovery Early Career Researcher Award - Grant ID: DE140100958
Funder
Australian Research Council
Funding Amount
$394,112.00
Summary
Understanding how shared between-sex genetic variance constrains the evolution of sexual dimorphism. Differences between males and females in the expression of shared traits have been of lasting interest to biologists. One fundamental question, which is as yet poorly understood, regards the extent to which a common genome restricts the independent evolution of the sexes. This project proposes a novel way of examining the degree to which the shared genetic architecture restricts the evolution of ....Understanding how shared between-sex genetic variance constrains the evolution of sexual dimorphism. Differences between males and females in the expression of shared traits have been of lasting interest to biologists. One fundamental question, which is as yet poorly understood, regards the extent to which a common genome restricts the independent evolution of the sexes. This project proposes a novel way of examining the degree to which the shared genetic architecture restricts the evolution of the sexes and the costs this imposes on population fitness. The results from the proposed experiments will give a clearer picture of how current measures reflect the true genetic constraint imposed on the sexes from a shared genetic architecture.Read moreRead less
Understanding phenotypes: contributions from studying mutations in a model organism. The distribution of fish across aquatic habitats will be determined jointly by the swimming speed and endurance requirements imposed by features of the environment, such as water flow, and by the swimming capacity of the fish. This project will use zebrafish to characterise how body shape and physiology interact to determine swimming capacity.
The nature of standing genetic variation. This project aims to expand understanding of the genetic variation underlying phenotypic differences among individuals. The nature of genetic variation has broad consequences across biology, from the detection of causal genetic variants to the adaptation of natural populations. This project will take a novel experimental approach to test several long-standing assumptions about the effects of new mutations on individual traits and their joint pleiotropic ....The nature of standing genetic variation. This project aims to expand understanding of the genetic variation underlying phenotypic differences among individuals. The nature of genetic variation has broad consequences across biology, from the detection of causal genetic variants to the adaptation of natural populations. This project will take a novel experimental approach to test several long-standing assumptions about the effects of new mutations on individual traits and their joint pleiotropic effect on fitness. By expanding our understanding of how mutation, selection and drift interact, this project could provide significant improvements in our understanding of the genetic basis of phenotypes, and our ability to predict phenotypic evolution.Read moreRead less
Sexual antagonism and the consequences of sex-specific selection. Males and females arise from essentially the same genome yet are selected in vastly different ways. This exposes gene pools to alternate episodes of feminising- and masculinising-selection, thereby promoting Sexually Antagonistic (SA) evolution. Sex chromosomes are predicted to play an important role in SA evolution because sex-linkage allows for gender-specific gene expression, but data on the role of sex-linked genes are limited ....Sexual antagonism and the consequences of sex-specific selection. Males and females arise from essentially the same genome yet are selected in vastly different ways. This exposes gene pools to alternate episodes of feminising- and masculinising-selection, thereby promoting Sexually Antagonistic (SA) evolution. Sex chromosomes are predicted to play an important role in SA evolution because sex-linkage allows for gender-specific gene expression, but data on the role of sex-linked genes are limited to Drosophila, a male heterogametic (XY) model. This project will determine the consequences of SA selection in the butterfly Eurema hecabe (a female ZW heterogamete) using experimental evolution and the feminising endosymbiont Wolbachia to force male genomes through bouts of feminising selection.Read moreRead less
Understanding rapid adaptation to new environments. This project aims to improve understanding of the process of rapid adaptation. Through both in situ changes and movement of individuals, populations are increasingly encountering new environments, where they risk extinction or become invasive. The fate of populations is determined by how rapidly they adapt to their new environmental conditions. Recent theory predicts adaptation to novel environments is fastest when selection acts on environment ....Understanding rapid adaptation to new environments. This project aims to improve understanding of the process of rapid adaptation. Through both in situ changes and movement of individuals, populations are increasingly encountering new environments, where they risk extinction or become invasive. The fate of populations is determined by how rapidly they adapt to their new environmental conditions. Recent theory predicts adaptation to novel environments is fastest when selection acts on environment-specific genetic variation. This project will test this prediction using novel manipulations. Better understanding of adaptation will allow better prediction of the risks of both extinction and invasiveness of natural populations.Read moreRead less