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  • 1.
    Eklöf, Anna
    et al.
    Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.
    Helmus, Matthew R.
    Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.
    Moore, M.
    Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA.
    Allesina, Stefano
    Department of Ecology and Evolution, and Computation Institute, University of Chicago, Chicago, IL 60637, USA.
    Relevance of evolutionary history for food web structure2012In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 279, no 1733, p. 1588-1596Article in journal (Refereed)
    Abstract [en]

    Explaining the structure of ecosystems is one of the great challenges of ecology. Simple models for foodweb structure aim at disentangling the complexity of ecological interaction networks and detect the main forces that are responsible for their shape. Trophic interactions are influenced by species traits, which in turn are largely determined by evolutionary history. Closely related species are more likely to share similar traits, such as body size, feeding mode and habitat preference than distant ones. Here, we present a theoretical framework for analysing whether evolutionary history—represented by taxonomic classification—provides valuable information on food web structure. In doing so, we measure which taxonomic ranks better explain species interactions. Our analysis is based on partitioning of the species into taxonomic units. For each partition, we compute the likelihood that a probabilistic model for food web structurere produces the data using this information. We find that taxonomic partitions produce significantly higher likelihoods than expected at random. Marginal likelihoods (Bayes factors) are used to perform model selection among taxonomic ranks. We show that food webs are best explained by the coarser taxonomic ranks (kingdom to class). Our methods provide a way to explicitly include evolutionary history in models for food web structure.

  • 2.
    Favati, Anna
    et al.
    Stockholm University, Sweden.
    Leimar, Olof
    Stockholm University, Sweden.
    Radesäter, Tommy
    Stockholm University, Sweden.
    Løvlie, Hanne
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology. Stockholm University, Sweden.
    Social status and personality: stability in social state can promote consistency of behavioural responses2014In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, no 1774, p. 20132531-Article in journal (Refereed)
    Abstract [en]

    Stability of ‘state’ has been suggested as an underlying factor explainingbehavioural stability and animal personality (i.e. variation among, andconsistency within individuals in behavioural responses), but the possibilitythat stable social relationships represent such states remains unexplored.Here, we investigated the influence of social status on the expression andconsistency of behaviours by experimentally changing social status betweenrepeated personality assays. We used male domestic fowl (Gallus gallusdomesticus), a social species that forms relatively stable dominance hierarchies,and showed that behavioural responses were strongly affected bysocial status, but also by individual characteristics. The level of vigilance,activity and exploration changed with social status, whereas boldnessappeared as a stable individual property, independent of status. Furthermore,variation in vocalization predicted future social status, indicatingthat individual behaviours can both be a predictor and a consequence ofsocial status, depending on the aspect in focus. Our results illustrate thatsocial states contribute to both variation and stability in behaviouralresponses, and should therefore be taken into account when investigatingand interpreting variation in personality.

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  • 3.
    Gillingham, Mark
    et al.
    University of Oxford, UK.
    Richardson, David
    University of East Anglia, UK.
    Løvlie, Hanne
    University of Oxford, UK.
    Moynihan, Anna
    University of Oxford, UK; University of Edinburgh, UK.
    Worley, Kirsty
    University of Oxford, UK; University of East Anglia, UK.
    Pizzari, Tom
    University of Oxford, UK.
    Cryptic preference for MHC-dissimilar females in male red junglefowl, Gallus gallus2009In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 276, no 1659, p. 1083-1092Article in journal (Refereed)
    Abstract [en]

    An increasing number of studies test the idea that females increase offspring fitness by biasing fertilization in favour of genetically compatible partners; however, few have investigated or controlled for corresponding preferences in males. Here, we experimentally test whether male red junglefowl, Gallus gallus, prefer genetically compatible females, measured by similarity at the major histocompatibility complex (MHC), a key gene complex in vertebrate immune function. Theory predicts that because some degree of MHC heterozygosity favours viability, individuals should prefer partners that carry MHC alleles different from their own. While male fowl showed no preference when simultaneously presented with an MHC-similar and an MHC-dissimilar female, they showed a 'cryptic' preference, by allocating more sperm to the most MHC-dissimilar of two sequentially presented females. These results provide the first experimental evidence that males might respond to the MHC similarity of a female through differential ejaculate expenditure. By revealing that cryptic male behaviours may bias fertilization success in favour of genetically compatible partners, this study demonstrates the need to experimentally disentangle male and female effects when studying preferences for genetically compatible partners.

  • 4.
    Gudmundson, Sara
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Eklöf, Anna
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Wennergren, Uno
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Environmental variability uncovers disruptive effects of species interactions on population dynamics2015In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, no 1812, p. 67-75Article in journal (Refereed)
    Abstract [en]

    How species respond to changes in environmental variability has been shown for single species, but the question remains whether these results are transferable to species when incorporated in ecological communities. Here, we address this issue by analysing the same species exposed to a range of environmental variabilities when (i) isolated or (ii) embedded in a food web. We find that all species in food webs exposed to temporally uncorrelated environments (white noise) show the same type of dynamics as isolated species, whereas species in food webs exposed to positively autocorrelated environments (red noise) can respond completely differently compared with isolated species. This is owing to species following their equilibrium densities in a positively autocorrelated environment that in turn enables species species interactions to come into play. Our results give new insights into species response to environmental variation. They especially highlight the importance of considering both species interactions and environmental autocorrelation when studying population dynamics in a fluctuating environment.

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  • 5. Hansson, Lars-Anders
    et al.
    Brönmark, Christer
    Nyström, Per
    Greenberg, Larry
    Lundberg, Per
    Nilsson, Anders
    Persson, Anders
    Pettersson, Lars
    Romare, Pia
    Tranvik, Lars
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Consumption patterns, complexity and enrichment in aquatic food chains1998In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 265, p. 901-906Article in journal (Refereed)
    Abstract [en]

       

  • 6.
    Keynes, RD
    et al.
    University of Cambridge.
    Elinder, Fredrik
    Karolinska Institute.
    Modelling the activation, opening, inactivation and reopening of the voltage-gated sodium channel1998In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 265, no 1393, p. 263-270Article in journal (Refereed)
    Abstract [en]

    A model of the voltage-gated sodium channel is put forward suggesting that the four S4 voltage-sensors behave as screw-helices making a series of discrete transitions that carry one elementary charge for each notch of the screw helix. After the channel has been activated by the first two steps R reversible arrow P reversible arrow A in all four domains, followed by a voltage-independent rearrangement, it is opened by a third cooperative step A reversible arrow B in domains I, II and III in conjunction with hydration. Inactivation is a voltage-dependent process controlled by the third step A reversible arrow I in sensor IVS4, and the closing of the channel is brought about its dehydration. From the inactivated steady state the channel may be reopened by a fourth step, I reversible arrow C in sensor IVS4 and rehydration. The computed kinetics of the model are shown to conform closely with those observed experimentally.

  • 7.
    Keynes, RD
    et al.
    University of Cambridge.
    Elinder, Fredrik
    Karolinska Institute.
    On the slowly rising phase of the sodium gating current in the squid giant axon1998In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 265, no 1393, p. 255-262Article in journal (Refereed)
    Abstract [en]

    High-resolution records of the sodium gating current in the squid giant axon demonstrate the existence of a slowly rising phase that is first apparent at pulse potentials slightly below zero, and becomes increasingly pronounced at more positive potentials. At +80 mV the current reaches its peak with a delay of 30 mu s at 10 degrees C. It is suggested that this current is generated by the first two steps labelled R--greater thanP and P--greater thanA in the S4 units of all four domains of the series-parallel gating system, activating the channel before its opening by the third steps A--greater thanB in domains I, II and III in conjunction with hydration. The kinetics of the slowly rising phase can only be explained by the incorporation of an appropriate degree of voltage-dependent cooperativity between the S4 voltage-sensors for their two initial transitions.

  • 8.
    Keynes, RD
    et al.
    University of Cambridge.
    Elinder, Fredrik
    Karolinska Institute.
    The screw-helical voltage gating of ion channels1999In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 266, no 1421, p. 843-852Article in journal (Refereed)
    Abstract [en]

    In the voltage-gated ion channels of every animal, whether they are selective for K+, Na+ or Ca2+, the voltage sensors are the S4 transmembrane segments carrying four to eight positive charges always separated by two uncharged residues. It is proposed that they move across the membrane in a screw-helical fashion in a series of three or more steps that each transfer a single electronic charge. The unit steps are stabilized by ion pairing between the mobile positive charges and fixed negative charges, of which there are invariably two located near the inner ends of segments S2 and S3 and a third near the outer end of either S2 or S3. Opening of the channel involves three such steps in each domain.

  • 9.
    Latorre-Margalef, N
    et al.
    Länssjukhuset Kalmar.
    Gunnarsson, G
    Länssjukhuset Kalmar.
    Munster, V J
    Länssjukhuset Kalmar.
    Fouchier, R A
    Länssjukhuset Kalmar.
    Osterhaus, A D
    Länssjukhuset Kalmar.
    Elmberg, J
    Länssjukhuset Kalmar.
    Olsen, B
    Länssjukhuset Kalmar.
    Wallensten, A
    Länssjukhuset Kalmar.
    Haemig, P D
    Länssjukhuset Kalmar.
    Fransson, t
    Länssjukhuset Kalmar.
    Brudin, Lars
    University of Kalmar .
    Waldenström, J
    Länssjukhuset Kalmar.
    Effects of influenza A virus infection on migrating mallard ducks.2009In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 22, p. 1029-1036Article in journal (Refereed)
    Abstract [en]

    The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002–2007, we collected faecal samples (n=10 918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales.

  • 10.
    Lindström, Tom
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology . Linköping University, The Institute of Technology.
    Håkansson, Nina
    Skövde University.
    Wennergren, Uno
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology . Linköping University, The Institute of Technology.
    The shape of the spatial kernel and its implications for biological invasions in patchy environments2011In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 278, no 1711, p. 1564-1571Article in journal (Refereed)
    Abstract [en]

    Ecological and epidemiological invasions occur in a spatial context. In the study presented we tested how these processes relate to the distance dependence of spread or dispersal between spatial entities such as habitat patches or infective units. The distance dependence was described by a spatial kernel which can be characterized by its shape, quantified by kurtosis, and width, quantified by the kernel variance. We also introduced a method to analyze or generate non randomly distributed infective units or patches as point pattern landscapes. The method is based on Fourier transform and consists of two measures in the spectral representation; Continuity that relates to autocorrelation and Contrast that refers to difference in density of patches, or infective units, in different areas of the landscape. The method was also used to analyze some relevant empirical data where our results are expected to have implications for ecological or epidemiological studies. We analyzed distributions of large old trees (Quercus and Ulmus) as well as the distributions of farms (both cattle and pig) in Sweden. We tested the invasion speed in generated landscapes with different amount of Continuity and Contrast. The results showed that kurtosis, i.e. the kernel shape, was not important for predicting the invasion speed in randomly distributed patches or infective units. However, depending on the assumptions of dispersal, it may be highly important when the distribution of patches or infective units deviates from randomness, in particular when the Contrast is high. We conclude that speed of invasions and spread of diseases depends on its spatial context through the spatial kernel intertwined to the spatial structure. This implies high demands on the empirical data; it requires knowledge of both shape and width of the spatial kernel as well as spatial structure of patches or infective units.

  • 11.
    Løvlie, Hanne
    et al.
    Edward Grey Institute, University of Oxford, UK Stockholm University, Stockholm, Sweden.
    Gillingham, Mark A. F.
    Edward Grey Institute, University of Oxford, UK.
    Worley, Kirsty
    Edward Grey Institute, University of Oxford, UK .
    Pizzari, Tommaso
    Edward Grey Institute, University of Oxford, UK.
    Richardson, David S.
    School of Biological Sciences, University of East Anglia, Norwich, UK.
    Cryptic female choice favours sperm from major histocompatibility complex-dissimilar males2013In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 280, no 1769Article in journal (Refereed)
    Abstract [en]

    Cryptic female choice may enable polyandrous females to avoid inbreedingor bias offspring variability at key loci after mating. However, the role ofthese genetic benefits in cryptic female choice remains poorly understood.Female red junglefowl, Gallus gallus, bias sperm use in favour of unrelatedmales. Here, we experimentally investigate whether this bias is driven byrelatedness per se, or by similarity at the major histocompatibility complex(MHC), genes central to vertebrate acquired immunity, where polymorphismis critical to an individual’s ability to combat pathogens. Throughexperimentally controlled natural matings, we confirm that selection againstrelated males’ sperm occurs within the female reproductive tract but demonstratethat this is more accurately predicted by MHC similarity: controllingfor relatedness per se, more sperm reached the eggs when partners wereMHC-dissimilar. Importantly, this effect appeared largely owing to similarityat a single MHC locus (class I minor). Further, the effect of MHCsimilarity was lost following artificial insemination, suggesting that malephenotypic cues might be required for females to select sperm differentially.These results indicate that postmating mechanisms that reduce inbreedingmay do so as a consequence of more specific strategies of cryptic femalechoice promoting MHC diversity in offspring.

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  • 12.
    Løvlie, Hanne
    et al.
    Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
    Immonen, Elina
    Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
    Gustavsson, Emil
    Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
    Kazancioglu, Emil
    Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
    Arnqvist, Göran
    Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
    The influence of mitonuclear genetic variation on personality in seed beetles2014In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, no 1796Article in journal (Refereed)
    Abstract [en]

    There is a growing awareness of the influence of mitochondrial genetic variation on life-history phenotypes, particularly via epistatic interactions with nuclear genes. Owing to their direct effect on traits such as metabolic and growth rates, mitonuclear interactions may also affect variation in behavioural types or personalities (i.e. behavioural variation that is consistent within individuals, but differs among individuals). However, this possibility is largely unexplored. We used mitonuclear introgression lines, where three mitochondrial genomes were introgressed into three nuclear genetic backgrounds, to disentangle genetic effects on behavioural variation in a seed beetle. We found within-individual consistency in a suite of activity-related behaviours, providing evidence for variation in personality. Composite measures of overall activity of individuals in behavioural assays were influenced by both nuclear genetic variation and by the interaction between nuclear and mitochondrial genomes. More importantly, the degree of expression of behavioural and life-history phenotypes was correlated and mitonuclear genetic variation affected expression of these concerted phenotypes. These results show that mitonuclear genetic variation affects both behavioural and life-history traits, and they provide novel insights into the maintenance of genetic variation in behaviour and personality.

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  • 13.
    Maklakov, Alexei A
    et al.
    Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Sweden.
    Immler, Simone
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden.
    Løvlie, Hanne
    Department of Animal Ecology, Evolutionary Biology Centre, Uppsala University, Sweden.
    Flis, Ilona
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden.
    Friberg, Urban
    Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden.
    The effect of sexual harassment on lethal mutation rate in female Drosophila melanogaster2013In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 280, no 1750Article in journal (Refereed)
    Abstract [en]

    The rate by which new mutations are introduced into a population may have far-reaching implications for processes at the population level. Theory assumes that all individuals within a population have the same mutation rate, but this assumption may not be true. Compared with individuals in high condition, those in poor condition may have fewer resources available to invest in DNA repair, resulting in elevated mutation rates. Alternatively, environmentally induced stress can result in increased investment in DNA repair at the expense of reproduction. Here, we directly test whether sexual harassment by males, known to reduce female condition, affects female capacity to alleviate DNA damage in Drosophila melanogaster fruitflies. Female gametes can repair double-strand DNA breaks in sperm, which allows manipulating mutation rate independently from female condition. We show that male harassment strongly not only reduces female fecundity, but also reduces the yield of dominant lethal mutations, supporting the hypothesis that stressed organisms invest relatively more in repair mechanisms. We discuss our results in the light of previous research and suggest that social effects such as density and courtship can play an important and underappreciated role in mediating condition-dependent mutation rate.

  • 14.
    Malacrino, Antonino
    et al.
    Westfal Wilhelms Univ Munster, Germany; Univ Mediterranea Reggio Calabria, Italy.
    Iinatti Brengdahl, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Kimber, Christopher
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Mital, Avani
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Naresh, Vinesh Shenoi
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Mirabello, Claudio
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Friberg, Urban
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Ageing desexualizes the Drosophila brain transcriptome2022In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 289, no 1980, article id 20221115Article in journal (Refereed)
    Abstract [en]

    General evolutionary theory predicts that individuals in low condition should invest less in sexual traits compared to individuals in high condition. Whether this positive association between condition and investment also holds between young (high condition) and senesced (low condition) individuals is however less clear, since elevated investment into reproduction may be beneficial when individuals approach the end of their life. To address how investment into sexual traits changes with age, we study genes with sex-biased expression in the brain, the tissue from which sexual behaviours are directed. Across two distinct populations of Drosophila melanogaster, we find that old brains display fewer sex-biased genes, and that expression of both male-biased and female-biased genes converges towards a sexually intermediate phenotype owing to changes in both sexes with age. We further find that sex-biased genes in general show heightened age-dependent expression in comparison to unbiased genes and that age-related changes in the sexual brain transcriptome are commonly larger in males than females. Our results hence show that ageing causes a desexualization of the fruit fly brain transcriptome and that this change mirrors the general prediction that low condition individuals should invest less in sexual phenotypes.

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  • 15.
    Malacrinò, Antonino
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Ohio State Univ, OH 43210 USA.
    Kimber, Christopher
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Brengdahl, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Friberg, Urban
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Heightened condition-dependence of the sexual transcriptome as a function of genetic quality in Drosophila melanogaster head tissue2019In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 286, no 1906, article id 20190819Article in journal (Refereed)
    Abstract [en]

    Theory suggests sexual traits should show heightened condition-dependent expression. This prediction has been tested extensively in experiments where condition has been manipulated through environmental quality. Condition-dependence as a function of genetic quality has, however, only rarely been addressed, despite its central importance in evolutionary theory. To address the effect of genetic quality on expression of sexual and non-sexual traits, we here compare gene expression in Drosophila melanogaster head tissue between flies with intact genomes (high condition) and flies carrying a major deleterious mutation (low condition). We find that sex-biased genes show heightened condition-dependent expression in both sexes, and that expression in low condition males and females regresses towards a more similar expression profile. As predicted, sex-biased expression was more sensitive to condition in males compared to females, but surprisingly female-biased, rather than male-biased, genes show higher sensitivity to condition in both sexes. Our results thus support the fundamental predictions of the theory of condition-dependence when condition is a function of genetic quality.

  • 16.
    Naresh, Vinesh Shenoi
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Iinatti Brengdahl, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Grace, Jaime L.
    Loyola Univ, IL 60660 USA.
    Eriksson, Björn
    Swedish Univ Agr Sci, Sweden.
    Rydén, Patrik
    Umea Univ, Sweden; Umea Univ, Sweden.
    Friberg, Urban
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    A genome-wide test for paternal indirect genetic effects on lifespan in Drosophila melanogaster2022In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 289, no 1974, article id 20212707Article in journal (Refereed)
    Abstract [en]

    Exposing sires to various environmental manipulations has demonstrated that paternal effects can be non-trivial also in species where male investment in offspring is almost exclusively limited to sperm. Whether paternal effects also have a genetic component (i.e. paternal indirect genetic effects (PIGEs)) in such species is however largely unknown, primarily because of methodological difficulties separating indirect from direct effects of genes. PIGEs may nevertheless be important since they have the capacity to contribute to evolutionary change. Here we use Drosophila genetics to construct a breeding design that allows testing nearly complete haploid genomes (more than 99%) for PIGEs. Using this technique, we estimate the variance in male lifespan due to PIGEs among four populations and compare this to the total paternal genetic variance (the sum of paternal indirect and direct genetic effects). Our results indicate that a substantial part of the total paternal genetic variance results from PIGEs. A screen of 38 haploid genomes, randomly sampled from a single population, suggests that PIGEs also influence variation in lifespan within populations. Collectively, our results demonstrate that PIGEs may constitute an underappreciated source of phenotypic variation.

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  • 17.
    Nunez-Leon, Daniel
    et al.
    Univ Zurich, Switzerland.
    Cordero, Gerardo A.
    Univ Tubingen, Germany; Eberhard Karls Univ Tubingen, Germany.
    Schlindwein, Xenia
    Univ Tubingen, Germany; Eberhard Karls Univ Tubingen, Germany.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Stoeckli, Esther
    Univ Zurich, Switzerland.
    Sanchez-Villagra, Marcelo R.
    Univ Zurich, Switzerland.
    Werneburg, Ingmar
    Univ Tubingen, Germany; Eberhard Karls Univ Tubingen, Germany.
    Shifts in growth, but not differentiation, foreshadow the formation of exaggerated forms under chicken domestication2021In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 288, no 1953, article id 20210392Article in journal (Refereed)
    Abstract [en]

    Domestication provides an outstanding opportunity for biologists to explore the underpinnings of organismal diversification. In domesticated animals, selective breeding for exaggerated traits is expected to override genetic correlations that normally modulate phenotypic variation in nature. Whether this strong directional selection affects the sequence of tightly synchronized events by which organisms arise (ontogeny) is often overlooked. To address this concern, we compared the ontogeny of the red junglefowl (RJF) (Gallus gallus) to four conspecific lineages that underwent selection for traits of economic or ornamental value to humans. Trait differentiation sequences in embryos of these chicken breeds generally resembled the representative ancestral condition in the RJF, thus revealing that early ontogeny remains highly canalized even during evolution under domestication. This key finding substantiates that the genetic cost of domestication does not necessarily compromise early ontogenetic steps that ensure the production of viable offspring. Instead, disproportionate beak and limb growth (allometry) towards the end of ontogeny better explained phenotypes linked to intense selection for industrial-scale production over the last 100 years. Illuminating the spatial and temporal specificity of development is foundational to the enhancement of chicken breeds, as well as to ongoing research on the origins of phenotypic variation in wild avian species.

  • 18.
    Pizzari, Tommaso
    et al.
    University of Leeds, UK.
    Løvlie, Hanne
    Stockholm University, Sweden.
    Cornwallis, Charles K.
    University of Sheffield, UK.
    Sex-specific, counter-acting responses to inbreeding in a bird2004In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 271, no 1553, p. 2115-2121Article in journal (Refereed)
    Abstract [en]

    Inbreeding often depresses offspring fitness. Because females invest more than males in a reproductive event, inbreeding is expected to be more costly to mothers than fathers, creating a divergence between the reproductive interests of each sex and promoting sex-specific inbreeding strategies. Males and females may bias the probability of inbreeding by selecting copulation partners, and, in sexually promiscuous species, through male strategic sperm investment in different females and female selection of the sperm of different males. However, these processes are often difficult to study, and the way that different male and female strategies interact to determine inbreeding remains poorly understood. Here we demonstrate sex-specific, counteracting responses to inbreeding in the promiscuous red junglefowl, Gallus gallus. First, a male was just as likely to copulate with his full-sib sister as with an unrelated female. In addition, males displayed a tendency to: (i) initiate copulation faster when exposed to an unrelated female than when exposed to a sister, and (ii) inseminate more sperm into sisters than into unrelated females. Second, females retained fewer sperm following insemination by brothers, thus reducing the risk of inbreeding and counteracting male inbreeding strategies.

  • 19.
    Rice, William
    et al.
    Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, USA.
    Gavrilets, Sergey
    Department of Ecology and Evolutionary Biology / Department of Mathematics and the National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, USA.
    Friberg, Urban
    Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, USA / Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
    The evolution of sex-specific grandparental harm2010In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 277, no 1694, p. 2727-2735Article in journal (Refereed)
    Abstract [en]

    Recent empirical studies indicate that grandparents favour some categories of grandchildren over others. Here, we expand the previous theoretical foundation for this finding and show that grandchild-harming phenotypes are predicted to evolve by 'sexually antagonistic zygotic drive (SA-zygotic drive) of the sex chromosomes'. We use the logic of Hamilton's rule to develop a new 'no-cost-to-self nepotism rule' that greatly simplifies the determination of the invasion criteria for mutations that cause grandparents to harm grandchildren. We use this theory to generate predictions that distinguish SA-zygotic drive from theory based solely on paternity assurance. The major diagnostic prediction is that grandmothers, and to a lesser degree grandfathers, will evolve grandson-harming phenotypes that reduce the level of sib competition experienced by their more closely related granddaughters, especially in their sons' families. This prediction is supported by data from recent studies showing (i) grandmothers invest more in granddaughters than grandsons, and counterintuitively, (ii) paternal grandmothers reduce the survival of their grandsons. We conclude that SA-zygotic drive is plausibly operating in humans via sexually antagonistic grandparental care.

  • 20.
    Rollings, Nicky
    et al.
    University of Sydney, Australia.
    Uhrig, Emily
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Oregon State University, OR 97331 USA.
    Krohmer, Randolph W.
    St Xavier University, IL USA.
    Waye, Heather L.
    University of Minnesota, MN 56267 USA.
    Mason, Robert T.
    Oregon State University, OR 97331 USA.
    Olsson, Mats
    University of Gothenburg, Sweden.
    Whittington, Camilla M.
    University of Sydney, Australia.
    Friesen, Christopher R.
    University of Sydney, Australia.
    Age-related sex differences in body condition and telomere dynamics of red-sided garter snakes2017In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 284, no 1852, article id 20162146Article in journal (Refereed)
    Abstract [en]

    Life-history strategies vary dramatically between the sexes, which may drive divergence in sex-specific senescence and mortality rates. Telomeres are tandem nucleotide repeats that protect the ends of chromosomes from erosion during cell division. Telomeres have been implicated in senescence and mortality because they tend to shorten with stress, growth and age. We investigated age-specific telomere length in female and male red-sided garter snakes, Thamnophis sirtalis parietalis. We hypothesized that age-specific telomere length would differ between males and females given their divergent reproductive strategies. Male garter snakes emerge from hibernation with high levels of corticosterone, which facilitates energy mobilization to fuel mate-searching, courtship and mating behaviours during a two to four week aphagous breeding period at the den site. Conversely, females remain at the dens for only about 4 days and seem to invest more energy in growth and cellular maintenance, as they usually reproduce biennially. As male investment in reproduction involves a yearly bout of physiologically stressful activities, while females prioritize self-maintenance, we predicted male snakes would experience more age-specific telomere loss than females. We investigated this prediction using skeletochronology to determine the ages of individuals and qPCR to determine telomere length in a cross-sectional study. For both sexes, telomere length was positively related to body condition. Telomere length decreased with age in male garter snakes, but remained stable in female snakes. There was no correlation between telomere length and growth in either sex, suggesting that our results are a consequence of divergent selection on life histories of males and females. Different selection on the sexes may be the physiological consequence of the sexual dimorphism and mating system dynamics displayed by this species.

  • 21.
    Schäfer, Samuel
    et al.
    Linköping University, Department of Biomedical and Clinical Sciences, Division of Children's and Women's Health. Linköping University, Faculty of Medicine and Health Sciences. Univ Sydney, Australia.
    Sundling, Felicia
    Linköping University, Department of Biomedical and Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Univ Sydney, Australia.
    Liu, Anthony
    Univ Sydney, Australia.
    Raubenheimer, David
    Univ Sydney, Australia.
    Nanan, Ralph
    Univ Sydney, Australia.
    Firstborn sex defines early childhood growth of subsequent siblings2021In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 288, no 1942, article id 20202329Article in journal (Refereed)
    Abstract [en]

    Animal studies have shown that maternal resource allocation can be sex-biased in order to maximize reproductive success, yet this basic concept has not been investigated in humans. In this study, we explored relationships between maternal factors, offspring sex and prenatal and postnatal weight gain. Sex-specific regression models not only indicated that maternal ethnicity impacted male (n = 2456) and female (n = 1871) childrens postnatal weight gain differently but also that parity and mode of feeding influenced weight velocity of female (beta +/- s.e. = -0.31 +/- 0.11 kg, p = 0.005; beta +/- s.e. = -0.37 +/- 0.11 kg, p < 0.001) but not male offspring. Collectively, our findings imply that maternal resource allocation to consecutive offspring increases after a male firstborn. The absence of this finding in formula fed children suggests that this observation could be mediated by breast milk. Our results warrant further mechanistic and epidemiological studies to elucidate the role of breastfeeding on the programming of infant growth as well as of metabolic and cardiovascular diseases, with potential implications for tailoring infant formulae according to sex and birth order.

  • 22.
    Tan, Cedric K. W.
    et al.
    University of Oxford, England .
    Løvlie, Hanne
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology.
    Greenway, Elisabeth
    University of Oxford, England University of St Andrews, Scotland .
    Goodwin, Stephen F.
    University of Oxford, England .
    Pizzari, Tommaso
    University of Oxford, England .
    Wigby, Stuart
    University of Oxford, England .
    Correction: Sex-specific responses to sexual familiarity, and the role of olfaction in Drosophila: a new analysis confirms original results (vol 280, 20131691, 2013)2014In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 281, no 1783Article in journal (Other academic)
    Abstract [en]

    n/a

  • 23.
    Tan, Cedric K.W.
    et al.
    Edward Grey Institute, Department of Zoology, University of Oxford, UK.
    Løvlie, Hanne
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology. Oxford University, Oxford, UK.
    Greenway, Elisabeth
    Edward Grey Institute, Department of Zoology, University of Oxford, UK.
    Goodwin, Stephen F.
    Department of Physiology Anatomy and Genetics, University of Oxford, UK.
    Pizzari, Tommaso
    Edward Grey Institute, Department of Zoology, University of Oxford, UK.
    Wigby, Stuart
    Edward Grey Institute, Department of Zoology, University of Oxford, UK.
    Sex-specific responses to sexual familiarity, and the role of olfaction in Drosophila2013In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 280, no 1771, p. 20131691-Article in journal (Refereed)
    Abstract [en]

    Studies of mating preferences have largely neglected the potential effects ofindividuals encountering their previous mates (‘directly sexually familiar’),or new mates that share similarities to previous mates, e.g. from the samefamily and/or environment (‘phenotypically sexually familiar’). Here, weshow that male and female Drosophila melanogaster respond to the direct andphenotypic sexual familiarity of potential mates in fundamentally differentways. We exposed a single focal male or female to two potential partners. Inthe first experiment, one potential partner was novel (not previously encountered)and one was directly familiar (their previous mate); in the secondexperiment, one potential partner was novel (unrelated, and from a differentenvironment from the previous mate) and one was phenotypically familiar(from the same family and rearing environment as the previous mate). Wefound that males preferentially courted novel females over directly or phenotypicallyfamiliar females. By contrast, females displayed aweak preference fordirectly and phenotypically familiar males over novel males. Sex-specificresponses to the familiarity of potential mates were significantly weaker orabsent in Orco1 mutants, which lack a co-receptor essential for olfaction, indicatinga role for olfactory cues in mate choice over novelty. Collectively, ourresults show that direct and phenotypic sexual familiarity is detected througholfactory cues and play an important role in sex-specific sexual behaviour.

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  • 24.
    Zajitschek, Felix
    et al.
    Monash University, Australia; Uppsala University, Sweden.
    Zajitschek, Susanne R. K.
    Uppsala University, Sweden; Spanish Research Council CSIC, Spain.
    Canton, Cindy
    Uppsala University, Sweden.
    Georgolopoulos, Grigorios
    Uppsala University, Sweden.
    Friberg, Urban
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Uppsala University, Sweden.
    Maklakov, Alexei A.
    Uppsala University, Sweden.
    Evolution under dietary restriction increases male reproductive performance without survival cost2016In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 283, no 1825, p. 20152726-Article in journal (Refereed)
    Abstract [en]

    Dietary restriction (DR), a reduction in nutrient intake without malnutrition, is the most reproducible way to extend lifespan in a wide range of organisms across the tree of life, yet the evolutionary underpinnings of the DR effect on lifespan are still widely debated. The leading theory suggests that this effect is adaptive and results from reallocation of resources from reproduction to somatic maintenance, in order to survive periods of famine in nature. However, such response would cease to be adaptive when DR is chronic and animals are selected to allocate more resources to reproduction. Nevertheless, chronic DR can also increase the strength of selection resulting in the evolution of more robust genotypes. We evolved Drosophila melanogaster fruit flies on DR, standard and high adult diets in replicate populations with overlapping generations. After approximately 25 generations of experimental evolution, male DR flies had higher fitness than males from standard and high populations. Strikingly, this increase in reproductive success did not come at a cost to survival. Our results suggest that sustained DR selects for more robust male genotypes that are overall better in converting resources into energy, which they allocate mostly to reproduction.

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