Quantitative genetic variation for thermal performance curves within and among natural populations of Drosophila serrata

Mutation and natural selection shape the genetic variation in natural populations. Here, we directly estimated the spontaneous mutation rate by sequencing new Drosophila mutation accumulation lines maintained with minimal natural selection. We inferred strong stabilizing natural selection on quantitative traits because genetic variation among wild-derived inbred lines was much lower than predicted from a neutral model and the mutational effects were much larger than allelic effects of standing polymorphisms. Stabilizing selection could act directly on the traits, or indirectly from pleiotropic effects on fitness. However, our data are not consistent with simple models of mutation-stabilizing selection balance; therefore, further empirical work is needed to assess the balance of evolutionary forces responsible for quantitative genetic variation.

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The molecular basis of quantitative genetic variation in natural populations

Trends in Ecology & Evolution ◽

10.1016/s0169-5347(00)89119-3 ◽

1995 ◽

Vol 10 (8) ◽

pp. 324-328 ◽

Cited By ~ 72

Author(s):

Thomas Mitchell-Olds

Keyword(s):

Genetic Variation ◽

Molecular Basis ◽

Natural Populations ◽

Quantitative Genetic

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The evolutionary potential of diet-dependent effects on lifespan and fecundity in a multi-parental population of Drosophila melanogaster

10.1101/343947 ◽

2018 ◽

Cited By ~ 2

Author(s):

Enoch Ng’oma ◽

Wilton Fidelis ◽

Kevin M. Middleton ◽

Elizabeth G. King

Keyword(s):

Drosophila Melanogaster ◽

Genetic Variation ◽

Genetic Correlations ◽

Natural Populations ◽

Evolutionary Potential ◽

Fitness Components ◽

Nutrient Imbalance ◽

Quantitative Genetic ◽

Nutritional Conditions ◽

Quantitative Genetic Parameters

AbstractThe nutritional conditions experienced by a population play a major role in shaping trait evolution in many taxa. Constraints exerted by nutrient limitation or nutrient imbalance can influence the maximal value that fitness components such as reproduction and lifespan attains, and organisms may shift how resources are allocated to different structures and functions in response to changes in nutrition. Whether the phenotypic changes associated with changes in nutrition represent an adaptive response is largely unknown. Further, it is unclear whether the response of fitness components to diet even has the potential to evolve in most systems. In this study, we use an admixed multiparental population of Drosophila melanogaster reared in three different diet conditions to estimate quantitative genetic parameters for lifespan and fecundity. We find significant genetic variation for both traits in our population and show that lifespan has moderate to high heritabilities within diets. Genetic correlations for lifespan between diets were significantly less than one, demonstrating a strong genotype by diet interaction. These findings demonstrate substantial standing genetic variation in our population that is comparable to natural populations and highlights the potential for adaptation to changing nutritional environments.

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Competition in depleting resource environments shapes the thermal response of mosquito population fitness

10.1101/2021.02.12.430918 ◽

2021 ◽

Author(s):

Paul J. Huxley ◽

Kris A. Murray ◽

Lauren J. Cator ◽

Samraat Pawar

Keyword(s):

Temperature Dependence ◽

Thermal Performance ◽

Resource Dependence ◽

Natural Populations ◽

Effect Of Temperature ◽

Disease Vectors ◽

List Type ◽

Larval Competition ◽

Juvenile Mortality ◽

Performance Curves

ABSTRACTA population’s maximal growth rate (rm) depends on the survivorship, development, and reproduction of its individuals. In ectotherms, these (functional) traits respond predictably to temperature, which provides a basis for predicting how climatic warming could affect natural populations, including disease vectors and the diseases they transmit.Such predictions generally arise from mathematical models that incorporate the temperature-dependence of traits (thermal performance curves) measured under laboratory conditions. Therefore, the accuracy of these predictions depends on the relevance of lab-measured trait thermal performance curves to natural conditions. However, the joint effect of temperature and resource availability—another key limiting environmental factor in nature—on traits is largely unknown.We investigated how larval competition for ecologically-realistic depleting resources affects the thermal performance of rm and its underlying life history traits in the disease vector in Aedes aegypti. We show that competition at food concentrations below a certain threshold drastically depresses rm across the entire temperature range, causes it to peak at a lower temperature, and narrows the breadth of temperatures over which rm is positive (the thermal niche breath).This resource-dependence of the thermal performance curve of rm is driven primarily by the fact that competition delays development and increases juvenile mortality. This is compounded by reduced size at maturity, which in turn decreases adult lifespan and fecundity.These results show that intensified larval competition in depleting resource environments can significantly affect the temperature-dependence of rm by modulating the thermal responses of underlying traits in a predictable way. This has important implications for forecasting the effects of climate change on population dynamics in the field of not just disease vectors, but holometabolous insects in general.

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Quantitative genetics of temperature performance curves of Neurospora crassa

10.1101/2020.01.16.909093 ◽

2020 ◽

Author(s):

Neda N. Moghadam ◽

Karendeep Sidhu ◽

Pauliina A. M. Summanen ◽

Tarmo Ketola ◽

Ilkka Kronholm

Keyword(s):

Genetic Variation ◽

Neurospora Crassa ◽

Thermal Performance ◽

Quantitative Genetics ◽

Performance Curve ◽

Evolutionary Potential ◽

Genetic Constraints ◽

Trade Offs ◽

Performance Curves ◽

Different Temperatures

AbstractEarth’s temperature is increasing due to anthropogenic CO2 emissions; and organisms need either to adapt to higher temperatures, migrate into colder areas, or face extinction. Temperature affects nearly all aspects of an organism’s physiology via its influence on metabolic rate and protein structure, therefore genetic adaptation to increased temperature may be much harder to achieve compared to other abiotic stresses. There is still much to be learned about the evolutionary potential for adaptation to higher temperatures, therefore we studied the quantitative genetics of growth rates in different temperatures that make up the thermal performance curve of the fungal model system Neurospora crassa. We studied the amount of genetic variation for thermal performance curves and examined possible genetic constraints by estimating the G-matrix. We observed a substantial amount of genetic variation for growth in different temperatures, and most genetic variation was for performance curve elevation. Contrary to common theoretical assumptions, we did not find strong evidence for genetic trade-offs for growth between hotter and colder temperatures. We also simulated short term evolution of thermal performance curves of N. crassa, and suggest that they can have versatile responses to selection.

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Genetic Diversity of Plant Species in Glacier National Park: Implications for Management

The UW National Parks Service Research Station Annual Reports ◽

10.13001/uwnpsrc.1990.2875 ◽

1990 ◽

Vol 14 ◽

pp. 55-58

Author(s):

Thomas Mitchell-Olds

Keyword(s):

Genetic Diversity ◽

Genetic Variation ◽

National Park ◽

Biological Diversity ◽

Management Strategies ◽

Natural Populations ◽

Glacier National Park ◽

Isozyme Electrophoresis ◽

Quantitative Genetic ◽

Local Environments

Glacier National Park (GNP) is responsible for the management and preservation of biological diversity in the natural populations of plants and animals occurring within its boundaries. Information on existing levels of genetic variation within and among populations is a prerequisite for developing management strategies to maintain genetic diversity and to perform revegetation activities. We are using two methods to assess levels of genetic diversity and differentiation among populations: quantitative genetic analysis and isozyme (electrophoresis) analysis. To examine whether patterns of genetic variation and adaptation to local environments require that sites be revegetated with plants collected from nearby natural populations, or alternatively, whether transplants could be obtained from other sources; we are focussing on three experimental areas: 1. quantitative genetics; 2. electrophoresis, and 3. natural selection.

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Wild worm embryogenesis harbors ubiquitous polygenic modifier variation

eLife ◽

10.7554/elife.09178 ◽

2015 ◽

Vol 4 ◽

Cited By ~ 45

Author(s):

Annalise B Paaby ◽

Amelia G White ◽

David D Riccardi ◽

Kristin C Gunsalus ◽

Fabio Piano ◽

...

Keyword(s):

Genetic Variation ◽

Caenorhabditis Elegans ◽

Gene Function ◽

Natural Populations ◽

Complex Trait ◽

Genetic Modifiers ◽

Wild Type ◽

Cryptic Genetic Variation ◽

Quantitative Genetic ◽

In The Wild

Embryogenesis is an essential and stereotypic process that nevertheless evolves among species. Its essentiality may favor the accumulation of cryptic genetic variation (CGV) that has no effect in the wild-type but that enhances or suppresses the effects of rare disruptions to gene function. Here, we adapted a classical modifier screen to interrogate the alleles segregating in natural populations of Caenorhabditis elegans: we induced gene knockdowns and used quantitative genetic methodology to examine how segregating variants modify the penetrance of embryonic lethality. Each perturbation revealed CGV, indicating that wild-type genomes harbor myriad genetic modifiers that may have little effect individually but which in aggregate can dramatically influence penetrance. Phenotypes were mediated by many modifiers, indicating high polygenicity, but the alleles tend to act very specifically, indicating low pleiotropy. Our findings demonstrate the extent of conditional functionality in complex trait architecture.

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Testing evolutionary hypotheses about species borders: patterns of genetic variation towards the southern borders of two rainforest Drosophila and a related habitat generalist

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2008.1288 ◽

2009 ◽

Vol 276 (1661) ◽

pp. 1517-1526 ◽

Cited By ~ 33

Author(s):

Belinda van Heerwaarden ◽

Vanessa Kellermann ◽

Michele Schiffer ◽

Mark Blacket ◽

Carla M Sgrò ◽

...

Keyword(s):

Genetic Variation ◽

Species Group ◽

Starvation Resistance ◽

Limited Evidence ◽

Quantitative Genetic ◽

Eastern Australia ◽

Drosophila Serrata ◽

Southern Border ◽

Selection For ◽

Habitat Generalist

Several evolutionary hypotheses help explain why only some species adapt readily to new conditions and expand distributions beyond borders, but there is limited evidence testing these hypotheses. In this study, we consider patterns of neutral (microsatellite) and quantitative genetic variation in traits in three species of Drosophila from the montium species group in eastern Australia. We found little support for restricted or asymmetrical gene flow in any species. In rainforest-restricted Drosophila birchii , there was evidence of selection for increased desiccation and starvation resistance towards the southern border, and a reduction in genetic diversity in desiccation resistance at this border. No such patterns existed for Drosophila bunnanda , which has an even more restricted distribution. In the habitat generalist Drosophila serrata , there was evidence for geographic selection for wing size and development time, although clinal patterns for increased cold and starvation resistance towards the southern border could not be differentiated from neutral expectations. These findings suggest that borders in these species are not limited by low overall genetic variation but instead in two of the species reflect patterns of selection and genetic variability in key traits limiting borders.

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Maintenance of Quantitative Genetic Variation

10.1093/oso/9780198830870.003.0028 ◽

2018 ◽

Author(s):

Bruce Walsh ◽

Michael Lynch

Keyword(s):

Genetic Variation ◽

Quantitative Genetics ◽

Stabilizing Selection ◽

Quantitative Genetic ◽

Wide Range

One of the major unresolved issues in quantitative genetics is what accounts for the amount of standing genetic variation in traits. A wide range of models, all reviewed in this chapter, have been proposed, but none fit the data, either giving too much variation or too little apparent stabilizing selection.

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