| 1. |
- Niemi, MEK, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 2. |
- Kanai, M, et al.
(författare)
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- 2023
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swepub:Mat__t
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| 3. |
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| 13. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
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Risk factors for subarachnoid haemorrhage : a nationwide cohort of 950 000 adults
- 2019
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Ingår i: International Journal of Epidemiology. - : Oxford University Press. - 0300-5771 .- 1464-3685. ; 48:6, s. 2018-2025
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Subarachnoid haemorrhage (SAH) is a devastating disease, with high mortality rate and substantial disability among survivors. Its causes are poorly understood. We aimed to investigate risk factors for SAH using a novel nationwide cohort consortium.METHODS: We obtained individual participant data of 949 683 persons (330 334 women) between 25 and 90 years old, with no history of SAH at baseline, from 21 population-based cohorts. Outcomes were obtained from the Swedish Patient and Causes of Death Registries.RESULTS: During 13 704 959 person-years of follow-up, 2659 cases of first-ever fatal or non-fatal SAH occurred, with an age-standardized incidence rate of 9.0 [95% confidence interval (CI) (7.4-10.6)/100 000 person-years] in men and 13.8 [(11.4-16.2)/100 000 person-years] in women. The incidence rate increased exponentially with higher age. In multivariable-adjusted Poisson models, marked sex interactions for current smoking and body mass index (BMI) were observed. Current smoking conferred a rate ratio (RR) of 2.24 (95% CI 1.95-2.57) in women and 1.62 (1.47-1.79) in men. One standard deviation higher BMI was associated with an RR of 0.86 (0.81-0.92) in women and 1.02 (0.96-1.08) in men. Higher blood pressure and lower education level were also associated with higher risk of SAH.CONCLUSIONS: The risk of SAH is 45% higher in women than in men, with substantial sex differences in risk factor strengths. In particular, a markedly stronger adverse effect of smoking in women may motivate targeted public health initiatives.
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| 14. |
- de Jong, S, et al.
(författare)
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Applying polygenic risk scoring for psychiatric disorders to a large family with bipolar disorder and major depressive disorder
- 2018
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Ingår i: Communications biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 1, s. 163-
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Tidskriftsartikel (refereegranskat)abstract
- Psychiatric disorders are thought to have a complex genetic pathology consisting of interplay of common and rare variation. Traditionally, pedigrees are used to shed light on the latter only, while here we discuss the application of polygenic risk scores to also highlight patterns of common genetic risk. We analyze polygenic risk scores for psychiatric disorders in a large pedigree (n ~ 260) in which 30% of family members suffer from major depressive disorder or bipolar disorder. Studying patterns of assortative mating and anticipation, it appears increased polygenic risk is contributed by affected individuals who married into the family, resulting in an increasing genetic risk over generations. This may explain the observation of anticipation in mood disorders, whereby onset is earlier and the severity increases over the generations of a family. Joint analyses of rare and common variation may be a powerful way to understand the familial genetics of psychiatric disorders.
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| 15. |
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| 16. |
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| 18. |
- Arnau-Soler, A, et al.
(författare)
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Genome-wide by environment interaction studies of depressive symptoms and psychosocial stress in UK Biobank and Generation Scotland
- 2019
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Ingår i: Translational psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 9:1, s. 14-
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Tidskriftsartikel (refereegranskat)abstract
- Stress is associated with poorer physical and mental health. To improve our understanding of this link, we performed genome-wide association studies (GWAS) of depressive symptoms and genome-wide by environment interaction studies (GWEIS) of depressive symptoms and stressful life events (SLE) in two UK population-based cohorts (Generation Scotland and UK Biobank). No SNP was individually significant in either GWAS, but gene-based tests identified six genes associated with depressive symptoms in UK Biobank (DCC, ACSS3, DRD2, STAG1, FOXP2 and KYNU; p < 2.77 × 10−6). Two SNPs with genome-wide significant GxE effects were identified by GWEIS in Generation Scotland: rs12789145 (53-kb downstream PIWIL4; p = 4.95 × 10−9; total SLE) and rs17070072 (intronic to ZCCHC2; p = 1.46 × 10−8; dependent SLE). A third locus upstream CYLC2 (rs12000047 and rs12005200, p < 2.00 × 10−8; dependent SLE) when the joint effect of the SNP main and GxE effects was considered. GWEIS gene-based tests identified: MTNR1B with GxE effect with dependent SLE in Generation Scotland; and PHF2 with the joint effect in UK Biobank (p < 2.77 × 10−6). Polygenic risk scores (PRSs) analyses incorporating GxE effects improved the prediction of depressive symptom scores, when using weights derived from either the UK Biobank GWAS of depressive symptoms (p = 0.01) or the PGC GWAS of major depressive disorder (p = 5.91 × 10−3). Using an independent sample, PRS derived using GWEIS GxE effects provided evidence of shared aetiologies between depressive symptoms and schizotypal personality, heart disease and COPD. Further such studies are required and may result in improved treatments for depression and other stress-related conditions.
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| 19. |
- Berg, Elena C., et al.
(författare)
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Kin but less than kind : within-group male relatedness does not increase female fitness in seed beetles
- 2019
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : ROYAL SOC. - 0962-8452 .- 1471-2954. ; 286:1910, s. 1471-2954
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Tidskriftsartikel (refereegranskat)abstract
- Theory maintains within-group male relatedness can mediate sexual conflict by reducing male-male. competition and collateral harm to females. We tested whether male relatedness can lessen female harm in the seed beetle Callosobruchus maculatus. Male relatedness did not influence female lifetime reproductive success or individual fitness across two different ecologically relevant scenarios of mating competition. However, male relatedness marginally improved female survival. Because male relatedness improved female-survival in late life when C. maculatus females are no longer producing offspring, our results do not provide support for the role of within-group male relatedness in mediating sexual conflict. The fact that male relatedness improves the post-reproductive part of the female life cycle strongly suggests that the effect is non-adaptive. We discuss adaptive and non-adaptive mechanisms that could result in reduced female harm in this and previous studies, and suggest that cognitive error is a likely explanation.
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| 20. |
- Berger, David, et al.
(författare)
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Sexually antagonistic selection on genetic variation underlying both male and female same-sex sexual behavior
- 2016
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Intralocus sexual conflict, arising from selection for different alleles at the same locus in males and females, imposes a constraint on sex-specific adaptation. Intralocus sexual conflict can be alleviated by the evolution of sex-limited genetic architectures and phenotypic expression, but pleiotropic constraints may hinder this process. Here, we explored putative intralocus sexual conflict and genetic (co)variance in a poorly understood behavior with near male-limited expression. Same-sex sexual behaviors (SSBs) generally do not conform to classic evolutionary models of adaptation but are common in male animals and have been hypothesized to result from perception errors and selection for high male mating rates. However, perspectives incorporating sex-specific selection on genes shared by males and females to explain the expression and evolution of SSBs have largely been neglected.
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| 21. |
- Brodin, Tomas, et al.
(författare)
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Personality trait differences between mainland and island populations in the common frog (Rana temporaria)
- 2013
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Ingår i: Behavioral Ecology and Sociobiology. - : Springer Science and Business Media LLC. - 0340-5443 .- 1432-0762. ; 67:1, s. 135-143
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Tidskriftsartikel (refereegranskat)abstract
- Understanding and predicting species range expansions is an important challenge in modern ecology because of rapidly changing environments. Recent studies have revealed that consistent within-species variation in behavior (i.e., animal personality) can be imperative for dispersal success, a key process in range expansion. Here we investigate how habitat isolation can mediate differentiation of personality traits between recently founded island populations and the main population. We performed laboratory studies of boldness and exploration across life stages (tadpoles and froglets) using four isolated island populations and four mainland populations of the common frog (Rana temporaria). Both tadpoles and froglets from isolated populations were bolder and more exploratory than conspecifics from the mainland. Although the pattern can be influenced by possible differences in predation pressure, we suggest that this behavioral differentiation might be the result of a disperser-dependent founder effect brought on by an isolation-driven environmental filtering of animal personalities. These findings can have important implications for both species persistence in the face of climate change (i.e., range expansions) and ecological invasions as well as for explaining rapid speciation in isolated patches.
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| 22. |
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| 23. |
- Czamara, D, et al.
(författare)
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Integrated analysis of environmental and genetic influences on cord blood DNA methylation in new-borns
- 2019
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1, s. 2548-
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Tidskriftsartikel (refereegranskat)abstract
- Epigenetic processes, including DNA methylation (DNAm), are among the mechanisms allowing integration of genetic and environmental factors to shape cellular function. While many studies have investigated either environmental or genetic contributions to DNAm, few have assessed their integrated effects. Here we examine the relative contributions of prenatal environmental factors and genotype on DNA methylation in neonatal blood at variably methylated regions (VMRs) in 4 independent cohorts (overall n = 2365). We use Akaike’s information criterion to test which factors best explain variability of methylation in the cohort-specific VMRs: several prenatal environmental factors (E), genotypes in cis (G), or their additive (G + E) or interaction (GxE) effects. Genetic and environmental factors in combination best explain DNAm at the majority of VMRs. The CpGs best explained by either G, G + E or GxE are functionally distinct. The enrichment of genetic variants from GxE models in GWAS for complex disorders supports their importance for disease risk.
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| 24. |
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| 25. |
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| 26. |
- Johansson, Frank, et al.
(författare)
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Evolution of the G-matrix in life history traits in the common frog during a recent colonisation of an island system
- 2012
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Ingår i: Evolutionary Ecology. - : Springer Science and Business Media LLC. - 0269-7653 .- 1573-8477. ; 26:4, s. 863-878
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Tidskriftsartikel (refereegranskat)abstract
- Studies of genetic correlations between traits that ostensibly channel the path of evolution away from the direction of natural selection require information on key aspects such as ancestral phenotypes, the duration of adaptive evolution, the direction of natural selection, and genetic covariances. In this study we provide such information in a frog population system. We studied adaptation in life history traits to pool drying in frog populations on islands of known age, which have been colonized from a mainland population. The island populations show strong local adaptation in development time and size. We found that the first eigenvector of the variance-covariance matrix (g (max)) had changed between ancestral mainland populations and newly established island populations. Interestingly, there was no divergence in g (max) among island populations that differed in their local adaptation in development time and size. Thus, a major change in the genetic covariance of life-history traits occurred in the colonization of the island system, but subsequent local adaptation in development time took place despite the constraints imposed by the genetic covariance structure.
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| 27. |
- Johansson, Frank, et al.
(författare)
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Trait performance correlations across life stages under environmental stress conditions in the common frog, Rana temporaria
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:7, s. e11680-
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Tidskriftsartikel (refereegranskat)abstract
- If an organism's juvenile and adult life stages inhabit different environments, certain traits may need to be independently adapted to each environment. In many organisms, a move to a different environment during ontogeny is accompanied by metamorphosis. In such organisms phenotypic induction early in ontogeny can affect later phenotypes. In laboratory experiments we first investigated correlations between body morphology and the locomotor performance traits expressed in different life stages of the common frog, Rana temporaria: swimming speed and acceleration in tadpoles; and jump-distance in froglets. We then tested for correlations between these performances across life stages. We also subjected tadpoles to unchanging or decreasing water levels to explore whether decreasing water levels might induce any carry-over effects. Body morphology and performance were correlated in tadpoles; morphology and performance were correlated in froglets: hence body shape and morphology affect performance within each life stage. However, performance was decoupled across life stages, as there was no correlation between performance in tadpoles and performance in froglets. While size did not influence tadpole performance, it was correlated with performance of the metamorphosed froglets. Experiencing decreasing water levels accelerated development time, which resulted in smaller tadpoles and froglets, i.e., a carry-over effect. Interestingly, decreasing water levels positively affected the performance of tadpoles, but negatively affected froglet performance. Our results suggest that performance does not necessarily have to be correlated between life stages. However, froglet performance is size dependent and carried over from the tadpole stage, suggesting that some important size-dependent characters cannot be decoupled via metamorphosis.
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| 28. |
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| 29. |
- Lind, Martin I., Dr, et al.
(författare)
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Cost-free lifespan extension via optimization of gene expression in adulthood aligns with the developmental theory of ageing
- 2021
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : Royal Society. - 0962-8452 .- 1471-2954. ; 288:1944
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Tidskriftsartikel (refereegranskat)abstract
- Ageing evolves because the force of selection on traits declines with age but the proximate causes of ageing are incompletely understood. The 'disposable soma' theory of ageing (DST) upholds that competitive resource allocation between reproduction and somatic maintenance underpins the evolution of ageing and lifespan. In contrast, the developmental theory of ageing (DTA) suggests that organismal senescence is caused by suboptimal gene expression in adulthood. While the DST predicts the trade-off between reproduction and lifespan, the DTA predicts that age-specific optimization of gene expression can increase lifespan without reproduction costs. Here we investigated the consequences for lifespan, reproduction, egg size and individual fitness of early-life, adulthood and post-reproductive onset of RNAi knockdown of five 'longevity' genes involved in key biological processes in Caenorhabditis elegans. Downregulation of these genes in adulthood and/or during post-reproductive period increases lifespan, while we found limited evidence for a link between impaired reproduction and extended lifespan. Our findings demonstrate that suboptimal gene expression in adulthood often contributes to reduced lifespan directly rather than through competitive resource allocation between reproduction and somatic maintenance. Therefore, age-specific optimization of gene expression in evolutionarily conserved signalling pathways that regulate organismal life histories can increase lifespan without fitness costs.
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| 30. |
- Lind, Martin I., Dr, 1980-, et al.
(författare)
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Environmental variation mediates the evolution of anticipatory parental effects
- 2020
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Ingår i: Evolution Letters. - Oxford : John Wiley & Sons. - 2056-3744. ; 4:4, s. 371-381
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Tidskriftsartikel (refereegranskat)abstract
- Theory maintains that when future environment is predictable, parents should adjust the phenotype of their offspring to match the anticipated environment. The plausibility of positive anticipatory parental effects is hotly debated and the experimental evidence for the evolution of such effects is currently lacking. We experimentally investigated the evolution of anticipatory maternal effects in a range of environments that differ drastically in how predictable they are. Populations of the nematode Caenorhabditis remanei, adapted to 20°C, were exposed to a novel temperature (25°C) for 30 generations with either positive or zero correlation between parent and offspring environment. We found that populations evolving in novel environments that were predictable across generations evolved a positive anticipatory maternal effect, because they required maternal exposure to 25°C to achieve maximum reproduction in that temperature. In contrast, populations evolving under zero environmental correlation had lost this anticipatory maternal effect. Similar but weaker patterns were found if instead rate-sensitive population growth was used as a fitness measure. These findings demonstrate that anticipatory parental effects evolve in response to environmental change so that ill-fitting parental effects can be rapidly lost. Evolution of positive anticipatory parental effects can aid population viability in rapidly changing but predictable environments. © 2020 The Authors. Evolution Letters published by Wiley Periodicals LLC on behalf of Society for the Study of Evolution (SSE) and European Society for Evolutionary Biology (ESEB).
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| 31. |
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| 32. |
- Lind, Martin I., Dr, et al.
(författare)
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Experimentally reduced insulin/IGF‐1 signaling in adulthood extends lifespan of parents and improves Darwinian fitness of their offspring
- 2019
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Ingår i: Evolution Letters. - : Oxford University Press (OUP). - 2056-3744. ; 3:2, s. 207-216
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Tidskriftsartikel (refereegranskat)abstract
- Classical theory maintains that ageing evolves via energy trade-offs between reproduction and survival leading to accumulation of unrepaired cellular damage with age. In contrast, the emerging new theory postulates that ageing evolves because of deleterious late-life hyper-function of reproduction-promoting genes leading to excessive biosynthesis in late-life. The hyper-function theory uniquely predicts that optimizing nutrient-sensing molecular signaling in adulthood can simultaneously postpone ageing and increase Darwinian fitness. Here, we show that reducing evolutionarily conserved insulin/IGF-1 nutrient-sensing signaling via daf-2 RNA interference (RNAi) fulfils this prediction in Caenorhabditis elegans nematodes. Long-lived daf-2 RNAi parents showed normal fecundity as self-fertilizing hermaphrodites and improved late-life reproduction when mated to males. Remarkably, the offspring of daf-2 RNAi parents had higher Darwinian fitness across three different genotypes. Thus, reduced nutrient-sensing signaling in adulthood improves both parental longevity and offspring fitness supporting the emerging view that suboptimal gene expression in late-life lies at the heart of ageing.
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| 33. |
- Lind, Martin I., Dr, et al.
(författare)
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Gene flow and selection on phenotypic plasticity in an island system of rana temporaria
- 2011
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 65:3, s. 684-697
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Tidskriftsartikel (refereegranskat)abstract
- Gene flow is often considered to be one of the main factors that constrains local adaptation in a heterogeneous environment. However, gene flow may also lead to the evolution of phenotypic plasticity. We investigated the effect of gene flow on local adaptation and phenotypic plasticity in development time in island populations of the common frog Rana temporaria which breed in pools that differ in drying regimes. This was done by investigating associations between traits (measured in a common garden experiment) and selective factors (pool drying regimes and gene flow from other populations inhabiting different environments) by regression analyses and by comparing pairwise F(ST) values (obtained from microsatellite analyses) with pairwise Q(ST) values. We found that the degree of phenotypic plasticity was positively correlated with gene flow from other populations inhabiting different environments (among-island environmental heterogeneity), as well as with local environmental heterogeneity within each population. Furthermore, local adaptation, manifested in the correlation between development time and the degree of pool drying on the islands, appears to have been caused by divergent selection pressures. The local adaptation in development time and phenotypic plasticity is quite remarkable, because the populations are young (less than 300 generations) and substantial gene flow is present among islands.
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| 34. |
- Lind, Martin I., Dr, 1980-, et al.
(författare)
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Testing the role of phenotypic plasticity for local adaptation : growth and development in time-constrained Rana temporaria populations
- 2011
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Ingår i: Journal of Evolutionary Biology. - Oxford : Blackwell Publishing. - 1010-061X .- 1420-9101. ; 24:12, s. 2696-2704
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Tidskriftsartikel (refereegranskat)abstract
- Phenotypic plasticity can be important for local adaptation, because it enables individuals to survive in a novel environment until genetic changes have been accumulated by genetic accommodation. By analysing the relationship between development rate and growth rate, it can be determined whether plasticity in life-history traits is caused by changed physiology or behaviour. We extended this to examine whether plasticity had been aiding local adaptation, by investigating whether the plastic response had been fixed in locally adapted populations. Tadpoles from island populations of Rana temporaria, locally adapted to different pool-drying regimes, were monitored in a common garden. Individual differences in development rate were caused by different foraging efficiency. However, developmental plasticity was physiologically mediated by trading off growth against development rate. Surprisingly, plasticity has not aided local adaptation to time-stressed environments, because local adaptation was not caused by genetic assimilation but on selection on the standing genetic variation in development time.
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| 35. |
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| 36. |
- Mautz, Brian S., et al.
(författare)
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Dietary Restriction Improves Fitness of Aging Parents But Reduces Fitness of Their Offspring in Nematodes
- 2020
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Ingår i: The journals of gerontology. Series A, Biological sciences and medical sciences. - : Oxford University Press. - 1079-5006 .- 1758-535X. ; 75:5, s. 843-848
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Tidskriftsartikel (refereegranskat)abstract
- Dietary restriction (DR) is a well-established intervention to extend lifespan across taxa. Recent studies suggest that DR-driven lifespan extension can be cost-free, calling into question a central tenant of the evolutionary theory of aging. Nevertheless, boosting parental longevity can reduce offspring fitness. Such intergenerational trade-offs are often ignored but can account for the "missing costs" of longevity. Here, we use the nematode Caenorhabditis remanei to test for effects of DR by fasting on fitness of females and their offspring. Females deprived of food for 6 days indeed had increased fecundity, survival, and stress resistance after re-exposure to food compared with their counterparts with constant food access. However, offspring of DR mothers had reduced early and lifetime fecundity, slower growth rate, and smaller body size at sexual maturity. These findings support the direct trade-off between investment in soma and gametes challenging the hypothesis that increased somatic maintenance and impaired reproduction can be decoupled.
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| 37. |
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| 38. |
- Reger, Julia, et al.
(författare)
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Predation drives local adaptation of phenotypic plasticity
- 2018
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Ingår i: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 2:1, s. 100-107
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Tidskriftsartikel (refereegranskat)abstract
- Phenotypic plasticity is the ability of an individual genotype to alter aspects of its phenotype depending on the current environment. It is central to the persistence, resistance and resilience of populations facing variation in physical or biological factors. Genetic variation in plasticity is pervasive, which suggests its local adaptation is plausible. Existing studies on the adaptation of plasticity typically focus on single traits and a few populations, while theory about interactions among genes (for example, pleiotropy) suggests that a multi-trait, landscape scale (for example, multiple populations) perspective is required. We present data from a landscape scale, replicated, multi-trait experiment using a classic predator-prey system centred on the water flea Daphnia pulex. We find predator regime-driven differences in genetic variation of multivariate plasticity. These differences are associated with strong divergent selection linked to a predation regime. Our findings are evidence for local adaptation of plasticity, suggesting that responses of populations to environmental variation depend on the conditions in which they evolved in the past.
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| 39. |
- Rowiński, Piotr K., et al.
(författare)
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Parental effects influence life history traits and covary with an environmental cline in common frog populations
- 2020
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Ingår i: Oecologia. - : Springer Nature. - 0029-8549 .- 1432-1939. ; 192:4, s. 1013-1022
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Tidskriftsartikel (refereegranskat)abstract
- Across latitudinal clines, the juvenile developmental rates of ectotherms often covary with the length of the growing season, due to life-history trade-offs imposed by the time-constrained environments. However, as the start of the growing season often varies substantially across years, adaptive parental effects on juvenile developmental rates may mediate the costs of a delayed season. By employing a meta-analysis, we tested whether larval developmental rates across a latitudinal cline of the common frog (Rana temporaria) are affected by fluctuating onsets of breeding, across years. We predicted that larval developmental rate will be inversely related to the onset of breeding, and that northern populations will be more prone to shorten their developmental rate in response to late breeding, as the costs of delayed metamorphosis should be highest in areas with a shorter growing season. We found that the larval period of both northern and southern populations responded to parental environmental conditions to a similar degree in absolute terms, but in different directions. In northern populations, a late season start correlated with decreased development time, suggesting that the evolution of parental effects aids population persistence in time-constrained environments. In southern populations, late season start correlated with increased development time, which could potentially be explained as a predator avoidance strategy. Our findings suggest that local ecological variables can induce adaptive parental effects, but responses are complex, and likely trade-off with other ecological factors.
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| 40. |
- Segami, Julia Carolina, et al.
(författare)
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Should females prefer old males?
- 2021
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Ingår i: Evolution Letters. - : John Wiley & Sons. - 2056-3744. ; 5:5, s. 507-520
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Tidskriftsartikel (refereegranskat)abstract
- Whether females should prefer to mate with old males is controversial. Old males may sire offspring of low quality because of an aging germline, but their proven ability to reach an old age can also be an excellent indicator of superior genetic quality, especially in natural populations. These genetic effects are, however, hard to study in nature, because they are often confounded with direct benefits offered by old males to the female, such as experience and high territory quality. We, therefore, used naturally occurring extra-pair young to disentangle different aspects of male age on female fitness in a natural population of collared flycatchers because any difference between within- and extra-pair young within a nest should be caused by paternal genetic effects only. Based on 18 years of long-term data, we found that females paired with older males as social partners experienced an overall reproductive advantage. However, offspring sired by old males were of lower quality as compared to their extra-pair half-siblings, whereas the opposite was found in nests attended by young males. These results imply a negative genetic effect of old paternal age, given that extra-pair males are competitive middle-age males. Thus, offspring may benefit from being sired by young males but raised by old males, to maximize both genetic and direct effects. Our results show that direct and genetic benefits from pairing with old males may act in opposing directions and that the quality of the germline may deteriorate before other signs of senescence become obvious.
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| 41. |
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| 42. |
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| 43. |
- Sekajova, Zuzana, et al.
(författare)
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Temperature-induced compensatory growth in C. elegans is regulated by thermosensitive TRP channel and increases reproductive fitness
- 2022
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Ingår i: Functional Ecology. - : John Wiley & Sons. - 0269-8463 .- 1365-2435. ; 36:9, s. 2176-2187
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Tidskriftsartikel (refereegranskat)abstract
- Animals are often not growing at the maximum rate, but can compensate for a bad start of life by subsequently increasing growth rate. While this compensatory growth is widespread, its direct fitness consequences are seldom investigated and its genetic basis is unknown.We investigated the genetic regulation, as well as fitness and lifespan consequences of compensatory growth in response to temperature, using Caenorhabditis elegans knockout of the thermo-sensitive TRP ion channel TRPA-1, involved in temperature recognition. We exposed juvenile worms to cold, favourable (intermediate) or warm temperatures in order to delay or speed up development.Wild-type worms initially exposed to cold temperature experienced slower growth but after being switched to a more favourable temperature, they expressed compensatory growth and caught up in size. Those initially reared at warmer temperatures than favourable experienced slower growth and attained smaller adult size after being switched to the most favourable temperature.Compensatory growth also altered the reproductive schedule. While rate-sensitive individual fitness decreased by cold juvenile temperatures, as a direct effect of the substantial developmental delay, once worms returned to more favourable temperature, they shifted their reproductive schedule towards early reproduction. Therefore, when focusing on the post-treatment period, the reproductive rate increased even though lifetime reproductive success was unaffected. Surprisingly, compensatory growth did not reduce adult lifespan. In contrast to the findings for wild-type worms, juvenile temperature did not induce compensatory or slowed-down growth in the trpa-1 knockout mutants.We thus show that the trpa-1 is involved in the network regulating temperature-induced compensatory growth in C. elegans and that this compensatory growth can influence the reproductive rate.
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| 44. |
- Sekajova, Zuzana, et al.
(författare)
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Temperature-induced compensatory growth in the nematode Caenorhabditis elegans is regulated by a thermosensitive TRP channel and influences reproductive rate
- 2022
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Ingår i: Functional Ecology. - : Wiley. - 0269-8463 .- 1365-2435. ; 36:9, s. 2176-2187
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Tidskriftsartikel (refereegranskat)abstract
- Animals are often not growing at the maximum rate, but can compensate for a bad start of life by subsequently increasing growth rate. While this compensatory growth is widespread, its direct fitness consequences are seldom investigated and its genetic basis is unknown. We investigated the genetic regulation, as well as fitness and lifespan consequences of compensatory growth in response to temperature, using Caenorhabditis elegans knockout of the thermo-sensitive TRP ion channel TRPA-1, involved in temperature recognition. We exposed juvenile worms to cold, favourable (intermediate) or warm temperatures in order to delay or speed up development. Wild-type worms initially exposed to cold temperature experienced slower growth but after being switched to a more favourable temperature, they expressed compensatory growth and caught up in size. Those initially reared at warmer temperatures than favourable experienced slower growth and attained smaller adult size after being switched to the most favourable temperature. Compensatory growth also altered the reproductive schedule. While rate-sensitive individual fitness decreased by cold juvenile temperatures, as a direct effect of the substantial developmental delay, once worms returned to more favourable temperature, they shifted their reproductive schedule towards early reproduction. Therefore, when focusing on the post-treatment period, the reproductive rate increased even though lifetime reproductive success was unaffected. Surprisingly, compensatory growth did not reduce adult lifespan. In contrast to the findings for wild-type worms, juvenile temperature did not induce compensatory or slowed-down growth in the trpa-1 knockout mutants. We thus show that the trpa-1 is involved in the network regulating temperature-induced compensatory growth in C. elegans and that this compensatory growth can influence the reproductive rate. Read the free Plain Language Summary for this article on the Journal blog.
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| 45. |
- Spagopoulou, Foteini, et al.
(författare)
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Silver-spoon upbringing improves early-life fitness but promotes reproductive ageing in a wild bird
- 2020
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 23:6, s. 994-1002
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Tidskriftsartikel (refereegranskat)abstract
- Early-life conditions can have long-lasting effects and organisms that experience a poor start in life are often expected to age at a faster rate. Alternatively, individuals raised in high-quality environments can overinvest in early-reproduction resulting in rapid ageing. Here we use a long-term experimental manipulation of early-life conditions in a natural population of collared flycatchers (Ficedula albicollis), to show that females raised in a low-competition environment (artificially reduced broods) have higher early-life reproduction but lower late-life reproduction than females raised in high-competition environment (artificially increased broods). Reproductive success of high-competition females peaked in late-life, when low-competition females were already in steep reproductive decline and suffered from a higher mortality rate. Our results demonstrate that 'silver-spoon' natal conditions increase female early-life performance at the cost of faster reproductive ageing and increased late-life mortality. These findings demonstrate experimentally that natal environment shapes individual variation in reproductive and actuarial ageing in nature.
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| 46. |
- Travers, Laura M., et al.
(författare)
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Beneficial cumulative effects of old parental age on offspring fitness
- 2021
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : Royal Society. - 0962-8452 .- 1471-2954. ; 288:1960
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Tidskriftsartikel (refereegranskat)abstract
- Old parental age is commonly associated with negative effects on offspring life-history traits. Such parental senescence effects are predicted to have a cumulative detrimental effect over successive generations. However, old parents may benefit from producing higher quality offspring when these compete for seasonal resources. Thus, old parents may choose to increase investment in their offspring, thereby producing fewer but larger and more competitive progeny. We show that Caenorhabditis elegans hermaphrodites increase parental investment with advancing age, resulting in fitter offspring who reach their reproductive peak earlier. Remarkably, these effects increased over six successive generations of breeding from old parents and were subsequently reversed following a single generation of breeding from a young parent. Our findings support the hypothesis that offspring of old parents receive more resources and convert them into increasingly faster life histories. These results contradict the theory that old parents transfer a cumulative detrimental 'ageing factor' to their offspring.
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| 47. |
- van Kolfschoten, Lisette, et al.
(författare)
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Rising temperatures threaten pollinators of fig trees—Keystone resources of tropical forests
- 2022
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 12:9
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Tidskriftsartikel (refereegranskat)abstract
- Pollinating insects are decreasing worldwide in abundance, biomass, and species richness, affecting the plants that rely on pollinators for fruit production and seed set. Insects are often sensitive to high temperatures. The projected temperature increases may therefore severely affect plants that rely on insect pollinators. Highly specialized mutualisms are expected to be particularly vulnerable to change because they have fewer partner options should one partner become unavailable. In the highly specialized mutualism between fig trees and their pollinating fig wasp, each fig species is pollinated by only one or a few wasp species. Because of their year-round fruit production, fig trees are considered a keystone resource for tropical forests. However, to produce fruits, wild fig trees need to be pollinated by fig wasps that typically travel a long one-way trip from the tree donating pollen to the tree receiving pollen. In a few previous studies from China and Australia, increasing temperatures dramatically decreased fig wasp lifespan. Are these grim results generalizable to fig mutualisms globally? Here, we use survival experiments to determine the effect of increasing temperature on the lifespan of Neotropical fig wasps associated with five common Panamanian Ficus species. Experimental temperatures were based on the current daytime mean temperature of 26.8°C (2SD: 21.6–31.7°C) and the predicted local temperature increase of 1–4°C by the end of the 21st century. We found that all tested pollinator wasp species had a significantly shorter lifespan in 30, 32, 34, and 36°C compared to the current diurnal mean temperature of 26°C. At 36°C pollinator median lifespan decreased to merely 2–10 h (6%–19% of their median lifespan at 26°C). Unless wasps can adapt, such a dramatic reduction in lifespan is expected to reduce the number of pollinators that successfully disperse to flowering fig trees, and may therefore jeopardize both fruit set and eventually survival of the mutualism.
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| 48. |
- Zwoinska, Martyna, et al.
(författare)
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Sexual conflict : male control of female longevity
- 2014
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 24:5
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Tidskriftsartikel (refereegranskat)abstract
- Males and females have different evolutionary interests resulting in sexual conflict over optimal life histories. A new study in Caenorhabditis elegans shows that males hijack female physiology after mating to cause body shrinking and, ultimately, death. But how do males benefit from female demise?
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