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Pierre Boudry - One of the best experts on this subject based on the ideXlab platform.
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Reproductive Effort of Pacific oysters: a trait associated with susceptibility to summer mortality.
Aquaculture, 2010Co-Authors: Arnaud Huvet, Julien Normand, Elodie Fleury, Virgile Quillien, Caroline Fabioux, Pierre BoudryAbstract:Summer mortality of the Pacific oyster Crassostrea gigas is the result of a complex interaction between oysters, their environment and their pathogens. The physiological status of an oyster, especially its Reproductive status, is suspected to play a significant role in the outcome of this interaction. As genetic variability exists for susceptibility to summer mortality, resistant (R) and susceptible (S) oyster lines were produced using a divergent selection scheme. The present paper reports a histological study on gonad area, which is representative of Reproductive Effort, in randomly chosen five R and five S oyster lines. The R lines showed a significantly lower gonad area than the S lines (P < 0.001), with an estimated mean difference of 12.5%, whereas, taken together, R and S lines showed a similar distribution of gametogenic stages when sampled. Considering the lines separately, the significant difference in gonad area went up to 24% between R and S lines. The present data confirm and strengthen the negative correlation between Reproductive Effort and resistance to summer mortality observed in previous studies. Summer mortality of C. gigas in France could, therefore, be partly due to a physiological disorder and metabolic disturbance in oysters associated with their Reproductive Effort. This does not, however, imply a direct link between the cost of reproduction and mortality because other causal factors, such as pathogenic agents, could be the primary causal factors.
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Reproductive Effort of Pacific oysters: A trait associated with susceptibility to summer mortality
Aquaculture, 2010Co-Authors: Arnaud Huvet, Julien Normand, Elodie Fleury, Virgile Quillien, Caroline Fabioux, Pierre BoudryAbstract:Texte intégral accessible à partir de Archimer: http://archimer.ifremer.fr/doc/00006/11766/8502.pdfInternational audienceSummer mortality of the Pacific oyster Crassostrea gigas is the result of a complex interaction between oysters, their environment and their pathogens. The physiological status of an oyster, especially its Reproductive status, is suspected to play a significant role in the outcome of this interaction. As genetic variability exists for susceptibility to summer mortality, resistant (R) and susceptible (S) oyster lines were produced using a divergent selection scheme. The present paper reports a histological study on gonad area, which is representative of Reproductive Effort, in randomly chosen five R and five S oyster lines. The R lines showed a significantly lower gonad area than the S lines (P < 0.001), with an estimated mean difference of 12.5%, whereas, taken together, R and S lines showed a similar distribution of gametogenic stages when sampled. Considering the lines separately, the significant difference in gonad area went up to 24% between R and S lines. The present data confirm and strengthen the negative correlation between Reproductive Effort and resistance to summer mortality observed in previous studies. Summer mortality of C. gigas in France could, therefore, be partly due to a physiological disorder and metabolic disturbance in oysters associated with their Reproductive Effort. This does not, however, imply a direct link between the cost of reproduction and mortality because other causal factors, such as pathogenic agents, could be the primary causal factors
Arnaud Huvet - One of the best experts on this subject based on the ideXlab platform.
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Reproductive Effort of Pacific oysters: a trait associated with susceptibility to summer mortality.
Aquaculture, 2010Co-Authors: Arnaud Huvet, Julien Normand, Elodie Fleury, Virgile Quillien, Caroline Fabioux, Pierre BoudryAbstract:Summer mortality of the Pacific oyster Crassostrea gigas is the result of a complex interaction between oysters, their environment and their pathogens. The physiological status of an oyster, especially its Reproductive status, is suspected to play a significant role in the outcome of this interaction. As genetic variability exists for susceptibility to summer mortality, resistant (R) and susceptible (S) oyster lines were produced using a divergent selection scheme. The present paper reports a histological study on gonad area, which is representative of Reproductive Effort, in randomly chosen five R and five S oyster lines. The R lines showed a significantly lower gonad area than the S lines (P < 0.001), with an estimated mean difference of 12.5%, whereas, taken together, R and S lines showed a similar distribution of gametogenic stages when sampled. Considering the lines separately, the significant difference in gonad area went up to 24% between R and S lines. The present data confirm and strengthen the negative correlation between Reproductive Effort and resistance to summer mortality observed in previous studies. Summer mortality of C. gigas in France could, therefore, be partly due to a physiological disorder and metabolic disturbance in oysters associated with their Reproductive Effort. This does not, however, imply a direct link between the cost of reproduction and mortality because other causal factors, such as pathogenic agents, could be the primary causal factors.
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Reproductive Effort of Pacific oysters: A trait associated with susceptibility to summer mortality
Aquaculture, 2010Co-Authors: Arnaud Huvet, Julien Normand, Elodie Fleury, Virgile Quillien, Caroline Fabioux, Pierre BoudryAbstract:Texte intégral accessible à partir de Archimer: http://archimer.ifremer.fr/doc/00006/11766/8502.pdfInternational audienceSummer mortality of the Pacific oyster Crassostrea gigas is the result of a complex interaction between oysters, their environment and their pathogens. The physiological status of an oyster, especially its Reproductive status, is suspected to play a significant role in the outcome of this interaction. As genetic variability exists for susceptibility to summer mortality, resistant (R) and susceptible (S) oyster lines were produced using a divergent selection scheme. The present paper reports a histological study on gonad area, which is representative of Reproductive Effort, in randomly chosen five R and five S oyster lines. The R lines showed a significantly lower gonad area than the S lines (P < 0.001), with an estimated mean difference of 12.5%, whereas, taken together, R and S lines showed a similar distribution of gametogenic stages when sampled. Considering the lines separately, the significant difference in gonad area went up to 24% between R and S lines. The present data confirm and strengthen the negative correlation between Reproductive Effort and resistance to summer mortality observed in previous studies. Summer mortality of C. gigas in France could, therefore, be partly due to a physiological disorder and metabolic disturbance in oysters associated with their Reproductive Effort. This does not, however, imply a direct link between the cost of reproduction and mortality because other causal factors, such as pathogenic agents, could be the primary causal factors
Simon Verhulst - One of the best experts on this subject based on the ideXlab platform.
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Experimentally increased brood size accelerates actuarial senescence and increases subsequent Reproductive Effort in a wild bird population
The Journal of animal ecology, 2020Co-Authors: Jelle J. Boonekamp, Christina Bauch, Simon VerhulstAbstract:The assumption that Reproductive Effort decreases somatic state, accelerating ageing, is central to our understanding of life‐history variation. Maximal Reproductive Effort early in life is predicted to be maladaptive by accelerating ageing disproportionally, decreasing fitness. Optimality theory predicts that Reproductive Effort is restrained early in life to balance the fitness contribution of reproduction against the survival cost induced by the Reproductive Effort. When adaptive, the level of Reproductive restraint is predicted to be inversely linked to the remaining life expectancy, potentially resulting in a terminal Effort in the last period of reproduction. Experimental tests of the Reproductive restraint hypothesis require manipulation of somatic state and subsequent investigation of Reproductive Effort and residual life span. To our knowledge the available evidence remains inconclusive, and hence Reproductive restraint remains to be demonstrated. We modulated somatic state through a lifelong brood size manipulation in wild jackdaws and measured its consequences for age‐dependent mortality and Reproductive success. The assumption that lifelong increased brood size reduced somatic state was supported: Birds rearing enlarged broods showed subsequent increased rate of actuarial senescence, resulting in reduced residual life span. The treatment induced a Reproductive response in later seasons: Egg volume and nestling survival were higher in subsequent seasons in the increased versus reduced broods' treatment group. We detected these increases in egg volume and nestling survival despite the expectation that in the absence of a change in Reproductive Effort, the reduced somatic state indicated by the increased mortality rate would result in lower Reproductive output. This leads us to conclude that the higher Reproductive success we observed was the result of higher Reproductive Effort. Our findings show that Reproductive Effort negatively covaries with remaining life expectancy, supporting optimality theory and confirming Reproductive restraint as a key factor underpinning life‐history variation.
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Reproductive Effort accelerates actuarial senescence in wild birds an experimental study
Ecology Letters, 2014Co-Authors: Jelle J. Boonekamp, Martijn Salomons, Sandra Bouwhuis, Cornelis Dijkstra, Simon VerhulstAbstract:Optimality theories of ageing predict that the balance between Reproductive Effort and somatic maintenance determines the rate of ageing. Laboratory studies find that increased Reproductive Effort shortens lifespan, but through increased short-term mortality rather than ageing. In contrast, high fecundity in early life is associated with accelerated senescence in free-living vertebrates, but these studies are non-experimental. We performed lifelong brood size manipulation in freeliving jackdaws. Actuarial senescence – the increase in mortality rate with age – was threefold higher in birds rearing enlarged- compared to reduced broods, confirming a key prediction of the optimality theory of ageing. Our findings contrast with the results of single-year brood size manipulation studies carried out in many species, in which there was no overall discernible manipulation effect on mortality. We suggest that our and previous findings are in agreement with predictions based on the reliability theory of ageing and propose further tests of this proposition.
Lars Gustafsson - One of the best experts on this subject based on the ideXlab platform.
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experimentally increased Reproductive Effort alters telomere length in the blue tit cyanistes caeruleus
Journal of Evolutionary Biology, 2014Co-Authors: Joanna Sudyka, Aneta Arct, Szymon M Drobniak, Anna Dubiec, Lars Gustafsson, Mariusz CichonAbstract:Telomeres have recently been suggested to play important role in ageing and are considered to be a reliable ageing biomarkers. The life history theory predicts that costs of reproduction should be expressed in terms of accelerated senescence, and some empirical studies do confirm such presumption. Thus, a link between Reproductive Effort and telomere dynamics should be anticipated. Recent studies have indeed demonstrated that reproduction may trigger telomere loss, but actual impact of Reproductive Effort has not received adequate attention in experimental studies. Here, we experimentally manipulated Reproductive Effort by increasing the brood size in the wild blue tit (Cyanistes caeruleus). We show that parents attending enlarged broods experienced larger yearly telomere decay in comparison to control birds attending unaltered broods. In addition, we demonstrate that the change in telomere length differs between sexes, but this effect was independent from our treatment. To our knowledge, this is the first experimental study in the wild revealing that telomere dynamics may be linked to Reproductive Effort. Thus, telomere shortening may constitute one of the potential proximate mechanisms mediating the costs of reproduction.
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Reproductive Effort reduces specific immune response and parasite resistance
Proceedings of the Royal Society of London. Series B: Biological Sciences, 1998Co-Authors: Dag Nordling, Måns Sverker Andersson, Siamak Zohari, Lars GustafssonAbstract:If a trade-off exists between Reproductive Effort and immune function, life-history decisions may have important implications for parasite resistance. Here, we report effects of experimental manipulation of Reproductive Effort on subsequent specific immune function and parasite resistance in the collared flycatcher, Ficedula albicollis. Our results show that increased Reproductive Effort of females immunized with Newcastle disease virus (NDV) vaccine negatively affected the ability to respond with NDV-specific antibodies. We further show that increased Reproductive Effort increased the intensity of Haemoproteus infections and that such infections are associated with higher mortality. Our results thus provide support for the hypothesis that immune suppression caused by Reproductive Effort may be an important mechanism mediating the life-history cost of reproduction.
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Infectious diseases, Reproductive Effort and the cost of reproduction in birds.
Philosophical transactions of the Royal Society of London. Series B Biological sciences, 1994Co-Authors: Lars Gustafsson, Dag Nordling, Måns Sverker Andersson, Ben C. Sheldon, Anna QvarnströmAbstract:Reproductive Effort can have profound effects on subsequent performance. Field experiments on the collared flycatcher (Ficedula albicollis) have demonstrated a number of trade-offs between life-history traits at different ages. The mechanism by which Reproductive Effort is mediated into future Reproductive performance remains obscure. Anti-parasite adaptations such as cell-mediated immunity may probably also be costly. Hence the possibility exists of a trade-off between Reproductive Effort and the ability to resist parasitic infection. Serological tests on unmanipulated collared flycatchers show that pre-breeding nutritional status correlates positively with Reproductive success and negatively with susceptibility to parasitism (viruses, bacteria and protozoan parasites). Both immune response and several indicators of infectious disease correlate negatively with Reproductive success. Similar relations are found between secondary sexual characters and infection parameters. For brood-size-manipulated birds there was a significant interaction between experimentally increased Reproductive Effort and parasitic infection rate with regard to both current and future fecundity. It seems possible that the interaction between parasitic infection, nutrition and Reproductive Effort can be an important mechanism in the ultimate shaping of life-history variation in avian populations.
Elodie Fleury - One of the best experts on this subject based on the ideXlab platform.
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Reproductive Effort of Pacific oysters: a trait associated with susceptibility to summer mortality.
Aquaculture, 2010Co-Authors: Arnaud Huvet, Julien Normand, Elodie Fleury, Virgile Quillien, Caroline Fabioux, Pierre BoudryAbstract:Summer mortality of the Pacific oyster Crassostrea gigas is the result of a complex interaction between oysters, their environment and their pathogens. The physiological status of an oyster, especially its Reproductive status, is suspected to play a significant role in the outcome of this interaction. As genetic variability exists for susceptibility to summer mortality, resistant (R) and susceptible (S) oyster lines were produced using a divergent selection scheme. The present paper reports a histological study on gonad area, which is representative of Reproductive Effort, in randomly chosen five R and five S oyster lines. The R lines showed a significantly lower gonad area than the S lines (P < 0.001), with an estimated mean difference of 12.5%, whereas, taken together, R and S lines showed a similar distribution of gametogenic stages when sampled. Considering the lines separately, the significant difference in gonad area went up to 24% between R and S lines. The present data confirm and strengthen the negative correlation between Reproductive Effort and resistance to summer mortality observed in previous studies. Summer mortality of C. gigas in France could, therefore, be partly due to a physiological disorder and metabolic disturbance in oysters associated with their Reproductive Effort. This does not, however, imply a direct link between the cost of reproduction and mortality because other causal factors, such as pathogenic agents, could be the primary causal factors.
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Reproductive Effort of Pacific oysters: A trait associated with susceptibility to summer mortality
Aquaculture, 2010Co-Authors: Arnaud Huvet, Julien Normand, Elodie Fleury, Virgile Quillien, Caroline Fabioux, Pierre BoudryAbstract:Texte intégral accessible à partir de Archimer: http://archimer.ifremer.fr/doc/00006/11766/8502.pdfInternational audienceSummer mortality of the Pacific oyster Crassostrea gigas is the result of a complex interaction between oysters, their environment and their pathogens. The physiological status of an oyster, especially its Reproductive status, is suspected to play a significant role in the outcome of this interaction. As genetic variability exists for susceptibility to summer mortality, resistant (R) and susceptible (S) oyster lines were produced using a divergent selection scheme. The present paper reports a histological study on gonad area, which is representative of Reproductive Effort, in randomly chosen five R and five S oyster lines. The R lines showed a significantly lower gonad area than the S lines (P < 0.001), with an estimated mean difference of 12.5%, whereas, taken together, R and S lines showed a similar distribution of gametogenic stages when sampled. Considering the lines separately, the significant difference in gonad area went up to 24% between R and S lines. The present data confirm and strengthen the negative correlation between Reproductive Effort and resistance to summer mortality observed in previous studies. Summer mortality of C. gigas in France could, therefore, be partly due to a physiological disorder and metabolic disturbance in oysters associated with their Reproductive Effort. This does not, however, imply a direct link between the cost of reproduction and mortality because other causal factors, such as pathogenic agents, could be the primary causal factors
