Project acronym ComplexSex
Project Sex-limited experimental evolution of natural and novel sex chromosomes: the role of sex in shaping complex traits
Researcher (PI) Jessica Abbott
Host Institution (HI) LUNDS UNIVERSITET
Call Details Starting Grant (StG), LS8, ERC-2015-STG
Summary The origin and evolution of sexual reproduction and sex differences represents one of the major unsolved problems in evolutionary biology, and although much progress had been made both via theory and empirical research, recent data suggest that sex chromosome evolution may be more complex than previously thought. The concept of sexual antagonism (when there is a positive intersexual genetic correlation in trait expression but opposite fitness effects of the trait(s) in males and females) has become essential to our understanding of sex chromosome evolution. The goal of this proposal is to understand how the interacting effects of sexual antagonism, sex-linked genetic variation, and sex-specific selection shape the genetic architecture of complex traits. I will test the hypotheses that: 1) individual sexually antagonistic loci are common in the genome, both in separate-sexed species and in hermaphrodites, and drive patterns of sexual antagonism often seen on the trait level. 2) That the response to sex-specific selection in sex-linked loci is usually due to standing sexually antagonistic genetic variation. 3) That sexually antagonistic variation is primarily non-additive in nature. To accomplish this, I will use a combination of approaches, including sex-limited experimental evolution of the X chromosome and reciprocal sex chromosome introgression among distantly related populations of Drosophila, quantitative genetic analysis and experimental evolution mimicking the creation of a novel sex chromosome in the hermaphroditic flatworm Macrostomum, and analytical and simulation modeling. This project will serve to confirm or refute the assumption that trait-level sexual antagonism reflects the contributions of many individual sexually antagonistic loci, increase our understanding of the contribution of coevolution of the sex chromosomes to population divergence, and help provide us with a better general understanding of how genotype maps to phenotype.
Summary
The origin and evolution of sexual reproduction and sex differences represents one of the major unsolved problems in evolutionary biology, and although much progress had been made both via theory and empirical research, recent data suggest that sex chromosome evolution may be more complex than previously thought. The concept of sexual antagonism (when there is a positive intersexual genetic correlation in trait expression but opposite fitness effects of the trait(s) in males and females) has become essential to our understanding of sex chromosome evolution. The goal of this proposal is to understand how the interacting effects of sexual antagonism, sex-linked genetic variation, and sex-specific selection shape the genetic architecture of complex traits. I will test the hypotheses that: 1) individual sexually antagonistic loci are common in the genome, both in separate-sexed species and in hermaphrodites, and drive patterns of sexual antagonism often seen on the trait level. 2) That the response to sex-specific selection in sex-linked loci is usually due to standing sexually antagonistic genetic variation. 3) That sexually antagonistic variation is primarily non-additive in nature. To accomplish this, I will use a combination of approaches, including sex-limited experimental evolution of the X chromosome and reciprocal sex chromosome introgression among distantly related populations of Drosophila, quantitative genetic analysis and experimental evolution mimicking the creation of a novel sex chromosome in the hermaphroditic flatworm Macrostomum, and analytical and simulation modeling. This project will serve to confirm or refute the assumption that trait-level sexual antagonism reflects the contributions of many individual sexually antagonistic loci, increase our understanding of the contribution of coevolution of the sex chromosomes to population divergence, and help provide us with a better general understanding of how genotype maps to phenotype.
Max ERC Funding
1 492 011 €
Duration
Start date: 2016-05-01, End date: 2021-04-30
Project acronym GENCON
Project The evolutionary implications of genetic conflict
Researcher (PI) Göran Arnqvist
Host Institution (HI) UPPSALA UNIVERSITET
Call Details Advanced Grant (AdG), LS8, ERC-2011-ADG_20110310
Summary The study of genetic conflict is developing at an almost explosive rate. The recognition that genes or alleles residing in individuals of the two sexes may have conflicting interests is transforming evolutionary biology and, likewise, conflict between genes showing different modes of transmission may fundamentally affect adaptive evolution. The research proposed here will push the frontiers of genetic conflict research and establish new domains. It is aimed at exploring the novel possibility that conflict between mitochondrial and nuclear genes have far-reaching implications for adaptive evolution and at advancing our understanding of the biological consequences of sexual conflict. The project consists of several interrelated parts and will employ insects as model systems. First, I will assess to what extent genetic variation in fitness is sexually antagonistic and what life history traits contribute to sexually antagonistic variation. Second, I will elucidate the genomics of metabolic rate and measure selection on metabolic phenotypes. Third, I will test whether sexually antagonistic epistatic interactions between mitochondrial and nuclear genes generate conflict over metabolic rate. Fourth, I will test the hypothesis that sexual conflict contribute to the evolution of primary and secondary sexual traits. Fifth, I will shed light on the complicated evolutionary interplay between sexual conflict and mating system evolution. I will employ an innovative research strategy, ‘experimental genomics’, in which genomic data is used to guide experimental evolutionary work with distinct genotypes. The research outlined here will collectively provide an unprecedented wealth of information into the role of genetic conflict in several horizons of adaptive evolution, ranging from DNA sequence evolution over life history evolution to speciation, and will set the standard for a new generation of insightful studies aimed at bridging the gap between phenotypic selection and genomics.
Summary
The study of genetic conflict is developing at an almost explosive rate. The recognition that genes or alleles residing in individuals of the two sexes may have conflicting interests is transforming evolutionary biology and, likewise, conflict between genes showing different modes of transmission may fundamentally affect adaptive evolution. The research proposed here will push the frontiers of genetic conflict research and establish new domains. It is aimed at exploring the novel possibility that conflict between mitochondrial and nuclear genes have far-reaching implications for adaptive evolution and at advancing our understanding of the biological consequences of sexual conflict. The project consists of several interrelated parts and will employ insects as model systems. First, I will assess to what extent genetic variation in fitness is sexually antagonistic and what life history traits contribute to sexually antagonistic variation. Second, I will elucidate the genomics of metabolic rate and measure selection on metabolic phenotypes. Third, I will test whether sexually antagonistic epistatic interactions between mitochondrial and nuclear genes generate conflict over metabolic rate. Fourth, I will test the hypothesis that sexual conflict contribute to the evolution of primary and secondary sexual traits. Fifth, I will shed light on the complicated evolutionary interplay between sexual conflict and mating system evolution. I will employ an innovative research strategy, ‘experimental genomics’, in which genomic data is used to guide experimental evolutionary work with distinct genotypes. The research outlined here will collectively provide an unprecedented wealth of information into the role of genetic conflict in several horizons of adaptive evolution, ranging from DNA sequence evolution over life history evolution to speciation, and will set the standard for a new generation of insightful studies aimed at bridging the gap between phenotypic selection and genomics.
Max ERC Funding
2 497 442 €
Duration
Start date: 2012-05-01, End date: 2017-04-30
Project acronym HeteroDynamic
Project Evolutionary Stability of Ubiquitous Root Symbiosis
Researcher (PI) Anna Rosling Larsson
Host Institution (HI) UPPSALA UNIVERSITET
Call Details Starting Grant (StG), LS8, ERC-2015-STG
Summary Virtually all terrestrial plants depend on symbiotic interactions with fungi. Arbuscular mycorrhizal (AM) fungi evolved over 450 million years ago, are obligate biotrophs and cannot complete their lifecycle without obtaining carbon from host roots. Mediating nutrient uptake and sequestering carbon in soil this symbiosis lie at the core of all terrestrial ecosystems. Plants on the other hand are facultative mycotrophs but under natural conditions all host roots are colonized as a result of multiple beneficial effects of AM fungi. In the symbiosis, both plants and fungi are promiscuous, forming interactions across individuals and species. In the absence of host-symbiont specificity and given their inability to discriminate among partners prior to interaction, evolutionary theory predicts that “free riders” would evolve and spread. Yet AM fungi remain evolutionary and ecologically successful. I propose that this is thanks to their unique genomic organization, a temporally dynamic heterokaryosis.
Unlike other eukaryotes, AM fungi have no single nucleate stage in their life cycle, instead they reproduce asexually by forming large multinucleate spores. Genetic variation is high and nuclei can migrate and mix within extensive mycelial networks. My group has recently established a single nucleus genomics method to study genetic variation among nuclei within AM fungi. With this method I can resolve the extent of heterokaryosis in AM fungi and its temporal dynamics. I will study the emergence of “free riders” upon intra organismal segregation of genetically distinct nuclei during AM fungal adaptation to host. Further I will study how hyphal fusion and nuclear mixing counteract segregation to stabilize the symbiosis. The research program has great potential for novel discoveries of fundamental importance to evolutionary and environmental biology and will also contribute to agricultural practice and management of terrestrial ecosystems.
Summary
Virtually all terrestrial plants depend on symbiotic interactions with fungi. Arbuscular mycorrhizal (AM) fungi evolved over 450 million years ago, are obligate biotrophs and cannot complete their lifecycle without obtaining carbon from host roots. Mediating nutrient uptake and sequestering carbon in soil this symbiosis lie at the core of all terrestrial ecosystems. Plants on the other hand are facultative mycotrophs but under natural conditions all host roots are colonized as a result of multiple beneficial effects of AM fungi. In the symbiosis, both plants and fungi are promiscuous, forming interactions across individuals and species. In the absence of host-symbiont specificity and given their inability to discriminate among partners prior to interaction, evolutionary theory predicts that “free riders” would evolve and spread. Yet AM fungi remain evolutionary and ecologically successful. I propose that this is thanks to their unique genomic organization, a temporally dynamic heterokaryosis.
Unlike other eukaryotes, AM fungi have no single nucleate stage in their life cycle, instead they reproduce asexually by forming large multinucleate spores. Genetic variation is high and nuclei can migrate and mix within extensive mycelial networks. My group has recently established a single nucleus genomics method to study genetic variation among nuclei within AM fungi. With this method I can resolve the extent of heterokaryosis in AM fungi and its temporal dynamics. I will study the emergence of “free riders” upon intra organismal segregation of genetically distinct nuclei during AM fungal adaptation to host. Further I will study how hyphal fusion and nuclear mixing counteract segregation to stabilize the symbiosis. The research program has great potential for novel discoveries of fundamental importance to evolutionary and environmental biology and will also contribute to agricultural practice and management of terrestrial ecosystems.
Max ERC Funding
1 500 000 €
Duration
Start date: 2016-04-01, End date: 2021-03-31
Project acronym NEWCONT
Project New Contexts for Old Texts: Unorthodox Texts and Monastic Manuscript Culture in Fourth- and Fifth-Century Egypt
Researcher (PI) Hugo Lundhaug
Host Institution (HI) UNIVERSITETET I OSLO
Call Details Starting Grant (StG), SH5, ERC-2011-StG_20101124
Summary "Using recently accessible Coptic monastic texts, new philology, and cognitive theories of literature and memory, this project aims to shed important new light on the production and use of some of the most enigmatic manuscripts discovered during the last century, namely the Nag Hammadi codices, together with the highly similar Berlin, Bruce, Askew, and Tchacos codices. This will be done by interpreting the contents of the codices as they are preserved to us in their Coptic versions primarily within the context of fourth- and fifth-century Egyptian monasticism and contemporary Coptic texts. This approach constitutes a decisive shift away from interpretations of the hypothetical Greek originals of this material within hypothetical first, second, or third century contexts all over the Mediterranean world, to a focus on the context of the production and use of the texts as they have been preserved in actual manuscripts. The project will approach the material from a New Philology perspective on manuscript culture, implying a focus on the users and producers of the extant manuscripts, and on textual variants, rewriting, and paratextual features as important clues. From this point of view, the project will also employ cognitive theories of literature and memory in order to illuminate early monastic attitudes towards books, canonicity, and doctrinal diversity in the context of monastic literary practices of copying, writing, memorization, and recitation, and the interfaces between orality and literacy. The project will thus combine new and traditional methodologies within a multi-disciplinary theoretical framework, thus bringing fresh theoretical and historico-philosophical approaches to bear on a traditionally methodologically conservative field of study, and has the potential to radically alter our picture of early Christian monasticism, manuscript culture, and doctrinal diversity."
Summary
"Using recently accessible Coptic monastic texts, new philology, and cognitive theories of literature and memory, this project aims to shed important new light on the production and use of some of the most enigmatic manuscripts discovered during the last century, namely the Nag Hammadi codices, together with the highly similar Berlin, Bruce, Askew, and Tchacos codices. This will be done by interpreting the contents of the codices as they are preserved to us in their Coptic versions primarily within the context of fourth- and fifth-century Egyptian monasticism and contemporary Coptic texts. This approach constitutes a decisive shift away from interpretations of the hypothetical Greek originals of this material within hypothetical first, second, or third century contexts all over the Mediterranean world, to a focus on the context of the production and use of the texts as they have been preserved in actual manuscripts. The project will approach the material from a New Philology perspective on manuscript culture, implying a focus on the users and producers of the extant manuscripts, and on textual variants, rewriting, and paratextual features as important clues. From this point of view, the project will also employ cognitive theories of literature and memory in order to illuminate early monastic attitudes towards books, canonicity, and doctrinal diversity in the context of monastic literary practices of copying, writing, memorization, and recitation, and the interfaces between orality and literacy. The project will thus combine new and traditional methodologies within a multi-disciplinary theoretical framework, thus bringing fresh theoretical and historico-philosophical approaches to bear on a traditionally methodologically conservative field of study, and has the potential to radically alter our picture of early Christian monasticism, manuscript culture, and doctrinal diversity."
Max ERC Funding
1 475 143 €
Duration
Start date: 2012-01-01, End date: 2016-12-31
Project acronym Optimal-Immunity
Project Optimal diversity in immunity – to overcome pathogens and maximize fitness; moving from correlative associations to a more mechanistic understanding using wild songbirds.
Researcher (PI) Karin Helena Westerdahl
Host Institution (HI) LUNDS UNIVERSITET
Call Details Starting Grant (StG), LS8, ERC-2015-STG
Summary The Major Histocompatibility Complex (MHC) genes are intensively studied genes in association with disease resistance. MHC proteins are essential for initiating every adaptive immune response and MHC is probably the most extreme example of how selection from a wide range of pathogens maintains high diversity in host immunity genes. However, the functions of the MHC proteins are only known in humans and model organisms, species that cannot be studied under natural conditions. There is therefore a need to study function of MHC proteins in species that can be thoroughly monitored in their natural habitat under varying pathogen regimes and over several generations. These parameters can be assessed in wild songbirds making them excellent study systems. Songbirds have large numbers of MHC gene copies, although little is known about how these affect their immune responses. Does high MHC copy number indicate that songbirds can recognize and combat more pathogens than other animals? They do fight infections satisfactory at their breeding, stopover and overwintering sites.
In this proposal my overarching aim is a more mechanistic understanding for survival and fitness linked to MHC in animals from wild populations and to take this field of research beyond the simple correlative associations that hitherto have been the rule. To reach this goal I must first characterize songbird MHC, now possible with ‘single molecule real time sequencing’. Therefore a rather substantial part of this proposal is technology. I will use two different songbird study systems; long-distance migratory great reed warblers and sedentary house sparrows and malaria-like pathogens infecting both these species. I am an experienced researcher on MHC and together with my team I will (1) characterize the MHC genomic region, (2) measure expression of MHC genes, (3) build MHC proteins and (4) measure functional MHC diversity in relation to fitness in wild birds, both in nature and in experimental set-ups.
Summary
The Major Histocompatibility Complex (MHC) genes are intensively studied genes in association with disease resistance. MHC proteins are essential for initiating every adaptive immune response and MHC is probably the most extreme example of how selection from a wide range of pathogens maintains high diversity in host immunity genes. However, the functions of the MHC proteins are only known in humans and model organisms, species that cannot be studied under natural conditions. There is therefore a need to study function of MHC proteins in species that can be thoroughly monitored in their natural habitat under varying pathogen regimes and over several generations. These parameters can be assessed in wild songbirds making them excellent study systems. Songbirds have large numbers of MHC gene copies, although little is known about how these affect their immune responses. Does high MHC copy number indicate that songbirds can recognize and combat more pathogens than other animals? They do fight infections satisfactory at their breeding, stopover and overwintering sites.
In this proposal my overarching aim is a more mechanistic understanding for survival and fitness linked to MHC in animals from wild populations and to take this field of research beyond the simple correlative associations that hitherto have been the rule. To reach this goal I must first characterize songbird MHC, now possible with ‘single molecule real time sequencing’. Therefore a rather substantial part of this proposal is technology. I will use two different songbird study systems; long-distance migratory great reed warblers and sedentary house sparrows and malaria-like pathogens infecting both these species. I am an experienced researcher on MHC and together with my team I will (1) characterize the MHC genomic region, (2) measure expression of MHC genes, (3) build MHC proteins and (4) measure functional MHC diversity in relation to fitness in wild birds, both in nature and in experimental set-ups.
Max ERC Funding
1 498 732 €
Duration
Start date: 2016-04-01, End date: 2021-03-31
