Polygenic dynamics underlying the response of quantitative traits to directional selection

Götsch, Hannah; Bürger, Reinhard

doi:10.1101/2023.02.23.529647

Cited by 4 publications

(9 citation statements)

References 110 publications

(223 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A related method, combining a Galton–Watson branching process with a deterministic logistic growth model, has recently been presented by Götsch and Bürger (2023) to study the adaptation of an additive QT under exponential directional selection from new mutation. Due to the absence of epistasis, the method can be set up in real time and allows for arbitrary locus effect sizes.…”

Section: Discussionmentioning

confidence: 99%

“…Due to the absence of epistasis, the method can be set up in real time and allows for arbitrary locus effect sizes. Götsch and Bürger (2023) use the number of segregating alleles under selection to characterize the adaptive architecture. Once again, the total population-scaled rate of new mutations

(the infinite-loci counterpart of our parameter

) emerges as the main determinant of the pattern of adaptation.…”

Section: Discussionmentioning

confidence: 99%

“…The loss of variation due to fixation of alleles is compensated by recurrent new mutation, as previously described by Hill (1982a , 1982b ) for adaptation of a quantitative trait under long-term truncation selection. A comprehensive discussion of both types of stable variance can be found in Götsch and Bürger (2023) .…”

Section: Discussionmentioning

confidence: 99%

“…1b ). Similar approaches have been used by Uecker and Hermisson (2011) and Martin and Lambert (2015) to describe the dynamics of a single locus and by Götsch and Bürger (2023) for independent loci.…”

Section: Model and Methodsmentioning

confidence: 98%

“…A2 shows the scaled number of generations (on the y -axis, in units of

) required for the mean phenotype

to reach passage points in units of mutational steps

( x -axis). To derive a simple analytical prediction for this dependence, we use a result by Götsch and Bürger (2023) for an additive trait under constant directional selection and constant rates of beneficial mutation (assumption of an infinite-locus model). Translated to our model parameters, Götsch and Bürger (2023 , Eq.…”

Section: Table A1mentioning

confidence: 99%

See 4 more Smart Citations

A theory of oligogenic adaptation of a quantitative trait

2023

View full text Add to dashboard Cite

Rapid phenotypic adaptation is widespread in nature, but the underlying genetic dynamics remain controversial. Whereas population genetics envisages sequential beneficial substitutions, quantitative genetics assumes a collective response through subtle shifts in allele frequencies. This dichotomy of a monogenic and a highly polygenic view of adaptation raises the question of a middle ground, as well as the factors controlling the transition. Here, we consider an additive quantitative trait with equal locus effects under Gaussian stabilizing selection that adapts to a new trait optimum after an environmental change. We present an analytical framework based on Yule branching processes to describe how phenotypic adaptation is achieved by collective changes in allele frequencies at the underlying loci. In particular, we derive an approximation for the joint allele-frequency distribution conditioned on the trait mean as a comprehensive descriptor of the adaptive architecture. Depending on the model parameters, this architecture reproduces the well-known patterns of sequential, monogenic sweeps, or of subtle, polygenic frequency shifts. Between these endpoints, we observe oligogenic architecture types that exhibit characteristic patterns of partial sweeps. We find that a single compound parameter, the population-scaled background mutation rate Θbg, is the most important predictor of the type of adaptation, while selection strength, the number of loci in the genetic basis, and linkage only play a minor role.

show abstract

Section: Discussionmentioning

confidence: 99%

(the infinite-loci counterpart of our parameter

) emerges as the main determinant of the pattern of adaptation.…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Model and Methodsmentioning

confidence: 98%

“…A2 shows the scaled number of generations (on the y -axis, in units of

) required for the mean phenotype

to reach passage points in units of mutational steps

Section: Table A1mentioning

confidence: 99%

See 3 more Smart Citations

A theory of oligogenic adaptation of a quantitative trait

2023

View full text Add to dashboard Cite

show abstract

Polygenic selection to a changing optimum under self–fertilisation

Hartfield

Glémin

2022

Preprint

View full text Add to dashboard Cite

Many traits are polygenic, affected by multiple genetic variants throughout the genome. Selection acting on these traits involves co–ordinated allele– frequency changes at these underlying variants, and this process has been extensively studied in random–mating populations. Yet many species self– fertilise to some degree, which incurs changes to genetic diversity, recombination and genome segregation. These factors cumulatively influence how polygenic selection is realised in nature. Here, we use simulations to investigate to what extent self–fertilisation affects polygenic adaptation to a new environment. We find that self–fertilisation can incur a fitness advantage through purging maladaptive genotypes. While the degree of self– fertilisation has little influence on how quickly a population adapts to a new optimum, those with the highest long–term fitness tended to have high levels of selfing (at least 90%). Very high levels of self–fertilisation (99% and above) causes fixation of variants with compensatory effects in elevated linkage disequilibrium across the genome. Conversely, if mutations are pleiotropic then only a few major–effect variants fix along with many neutral hitchhikers, with a transient increase in linkage disequilibrium. If deleterious mutations are also present then linkage–block formation is disrupted in highly–selfing species, with fewer mutations contributing to adaptation and less chance of high–linkage genomes persisting over time. We also show how these outcomes differ in outcrossing populations with rescaled mutation and recombination rates, demonstrating that elevated homozygosity also influences the selection response. These results show potential advantages to self–fertilisation when adapting to a new environment, and how the mating system affects the genetic composition of polygenic selection.Website for simulation codehttps://github.com/MattHartfield/Polygenic-Selfing

show abstract

A theory of oligogenic adaptation of a quantitative trait

Höllinger

Wölfl

Hermisson

2023

Preprint

View full text Add to dashboard Cite

Rapid phenotypic adaptation is widespread in nature, but the underlying genetic dynamics remain controversial. Whereas population genetics envisages sequential beneficial substitutions, quantitative genetics assumes a collective response through subtle shifts in allele frequencies. This dichotomy of a monogenic and a highly polygenic view of adaptation raises the question of a middle ground, as well as the factors controlling the transition. Here, we consider an additive quantitative trait with equal locus effects under Gaussian stabilizing selection that adapts to a new trait optimum after an environmental change. We present an analytical framework based on Yule branching processes to describe how phenotypic adaptation is achieved by collective changes in allele frequencies at the underlying loci. In particular, we derive an approximation for the joint allele-frequency distribution at threshold levels of the trait mean as a comprehensive descriptor of the adaptive architecture. Depending on the model parameters, this architecture reproduces the well-known patterns of sequential, monogenic sweeps, or of subtle, polygenic frequency shifts. Between these endpoints, we observe oligogenic architecture types that exhibit characteristic patterns of partial sweeps. We find that a single compound parameter, the population-scaled background mutation ratebg, is the most important predictor of the type of adaptation, while selection strength, the number of loci in the genetic basis, and linkage only play a minor role.

show abstract

Polygenic dynamics underlying the response of quantitative traits to directional selection

Cited by 4 publications

References 110 publications

A theory of oligogenic adaptation of a quantitative trait

A theory of oligogenic adaptation of a quantitative trait

Polygenic selection to a changing optimum under self–fertilisation

A theory of oligogenic adaptation of a quantitative trait

Contact Info

Product

Resources

About