The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Linda Partridge - One of the best experts on this subject based on the ideXlab platform.
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amino acid imbalance explains extension of lifespan by dietary restriction in drosophila
Nature, 2009Co-Authors: Richard C. Grandison, Matthew D W Piper, Linda PartridgeAbstract:In a number of organisms, dietary restriction has been shown to extend lifespan at the expense of reduced Fecundity. An example of competition for limited resources, the thinking generally goes, as nutrients are reallocated from reproduction to somatic maintenance. Grandison et al. now demonstrate that, in Drosophila, dietary restriction does not induce reallocation, because different amino acids limit lifespan and Fecundity. They find that Fecundity in long-life flies can be rescued by the addition of methionine alone. Long lifespan and high Fecundity can thus occur simultaneously, without dietary restriction itself, by adjustment of the ratio of amino acids in the diet. These findings imply that humans might be able to enjoy the benefits of reduced food intake, without the downsides, by adjustment of dietary nutrients. Dietary restriction extends healthy lifespan in diverse organisms but reduces Fecundity; this is thought to be because of an adaptive reallocation of nutrients from reproduction to somatic maintenance. Here, the nutrients producing the responses of lifespan and Fecundity to dietary restriction in Drosophila are identified. Adding essential amino acids to the dietary restriction condition increased Fecundity and decreased lifespan; furthermore, addition of methionine alone rescued Fecundity. Dietary restriction extends healthy lifespan in diverse organisms and reduces Fecundity1,2. It is widely assumed to induce adaptive reallocation of nutrients from reproduction to somatic maintenance, aiding survival of food shortages in nature3,4,5,6. If this were the case, long life under dietary restriction and high Fecundity under full feeding would be mutually exclusive, through competition for the same limiting nutrients. Here we report a test of this idea in which we identified the nutrients producing the responses of lifespan and Fecundity to dietary restriction in Drosophila. Adding essential amino acids to the dietary restriction condition increased Fecundity and decreased lifespan, similar to the effects of full feeding, with other nutrients having little or no effect. However, methionine alone was necessary and sufficient to increase Fecundity as much as did full feeding, but without reducing lifespan. Reallocation of nutrients therefore does not explain the responses to dietary restriction. Lifespan was decreased by the addition of amino acids, with an interaction between methionine and other essential amino acids having a key role. Hence, an imbalance in dietary amino acids away from the ratio optimal for reproduction shortens lifespan during full feeding and limits Fecundity during dietary restriction. Reduced activity of the insulin/insulin-like growth factor signalling pathway extends lifespan in diverse organisms7, and we find that it also protects against the shortening of lifespan with full feeding. In other organisms, including mammals, it may be possible to obtain the benefits to lifespan of dietary restriction without incurring a reduction in Fecundity, through a suitable balance of nutrients in the diet.
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Amino-acid imbalance explains extension of lifespan by dietary restriction in Drosophila
Nature, 2009Co-Authors: Richard C. Grandison, Matthew D W Piper, Linda PartridgeAbstract:Dietary restriction extends healthy lifespan in diverse organisms and reduces Fecundity(1,2). It is widely assumed to induce adaptive reallocation of nutrients from reproduction to somatic maintenance, aiding survival of food shortages in nature(3-6). If this were the case, long life under dietary restriction and high Fecundity under full feeding would be mutually exclusive, through competition for the same limiting nutrients. Here we report a test of this idea in which we identified the nutrients producing the responses of lifespan and Fecundity to dietary restriction in Drosophila. Adding essential amino acids to the dietary restriction condition increased Fecundity and decreased lifespan, similar to the effects of full feeding, with other nutrients having little or no effect. However, methionine alone was necessary and sufficient to increase Fecundity as much as did full feeding, but without reducing lifespan. Reallocation of nutrients therefore does not explain the responses to dietary restriction. Lifespan was decreased by the addition of amino acids, with an interaction between methionine and other essential amino acids having a key role. Hence, an imbalance in dietary amino acids away from the ratio optimal for reproduction shortens lifespan during full feeding and limits Fecundity during dietary restriction. Reduced activity of the insulin/insulin-like growth factor signalling pathway extends lifespan in diverse organisms(7), and we find that it also protects against the shortening of lifespan with full feeding. In other organisms, including mammals, it may be possible to obtain the benefits to lifespan of dietary restriction without incurring a reduction in Fecundity, through a suitable balance of nutrients in the diet.
Bob B M Wong - One of the best experts on this subject based on the ideXlab platform.
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female ornamentation and the Fecundity trade off in a sex role reversed pipefish
Ecology and Evolution, 2018Co-Authors: Kenyon B Mobley, John R Morrongiello, Matthew Warr, Dianne J Bray, Bob B M WongAbstract:Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female ornamentation and Fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width, and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female Fecundity. Rather, females that have larger ornaments have higher Fecundity and thus accurately advertise their reproductive value to males without incurring a cost to Fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffer a slight decrease in egg size and Fecundity, although this decrease was independent of female ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent Fecundity cost of ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female ornamentation.
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female ornamentation and the Fecundity trade off in a sex role reversed pipefish
bioRxiv, 2018Co-Authors: Kenyon B Mobley, John R Morrongiello, Matthew Warr, Dianne J Bray, Bob B M WongAbstract:Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female ornamentation and Fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female Fecundity. Rather, females that have larger ornaments have higher Fecundity and thus accurately advertise their reproductive value to males without incurring a cost to Fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffered a slight decrease in egg size and Fecundity, although this decrease was independent of female ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent Fecundity cost of ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female ornamentation.
Daniel Pincheira-donoso - One of the best experts on this subject based on the ideXlab platform.
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Fecundity selection theory: concepts and evidence
Biological Reviews, 2015Co-Authors: Daniel Pincheira-donoso, John HuntAbstract:Fitness results from an optimal balance between survival, mating success and Fecundity. The interactions between these three components of fitness vary depending on the selective context, from positive covariation between them, to antagonistic pleiotropic relationships when fitness increases in one reduce the fitness of others. Therefore, elucidating the routes through which selection shapes life history and phenotypic adaptations via these fitness components is of primary significance to understanding ecological and evolutionary dynamics. However, while the fitness components mediated by natural (survival) and sexual (mating success) selection have been debated extensively from most possible perspectives, Fecundity selection remains considerably less studied. Here, we review the theoretical basis, evidence and implications of Fecundity selection as a driver of sex-specific adaptive evolution. Based on accumulating literature on the life-history, phenotypic and ecological aspects of Fecundity, we (i) suggest a re-arrangement of the concepts of Fecundity, whereby we coin the term 'transient Fecundity' to refer to brood size per reproductive episode, while 'annual' and 'lifetime Fecundity' should not be used interchangeably with 'transient Fecundity' as they represent different life-history parameters; (ii) provide a generalized re-definition of the concept of Fecundity selection as a mechanism that encompasses any traits that influence Fecundity in any direction (from high to low) and in either sex; (iii) review the (macro)ecological basis of Fecundity selection (e.g. ecological pressures that influence predictable spatial variation in Fecundity); (iv) suggest that most ecological theories of Fecundity selection should be tested in organisms other than birds; (v) argue that the longstanding Fecundity selection hypothesis of female-biased sexual size dimorphism (SSD) has gained inconsistent support, that strong Fecundity selection does not necessarily drive female-biased SSD, and that this form of SSD can be driven by other selective pressures; and (vi) discuss cases in which Fecundity selection operates on males. This conceptual analysis of the theory of Fecundity selection promises to help illuminate one of the central components of fitness and its contribution to adaptive evolution.
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Fecundity selection theory: concepts and evidence
bioRxiv, 2015Co-Authors: Daniel Pincheira-donoso, John HuntAbstract:Fitness results from the optimal balance between survival, mating success and Fecundity. The interactions between these three components of fitness vary importantly depending on the selective context, from positive covariation between them, to antagonistic pleiotropic relationships when fitness increases in one reduce fitness of others. Therefore, elucidating the routes through which selection shapes life history and phenotypic adaptations via these fitness components is of primary significance to understand ecological and evolutionary dynamics. However, while the fitness components mediated by natural (survival) and sexual (mating success) selection have extensively been debated from most possible perspectives, Fecundity selection remains considerably less studied. Here, we review the theory, evidence and implications of Fecundity selection as a driver of sex-specific adaptive evolution. Based on accumulating literature on the life-history, phenotypic and ecological aspects of Fecundity, we (i) suggest that ‘Fecundity’ is restricted to refer to brood size per reproductive episode, while ‘annual’ and ‘lifetime Fecundity’ should not be used interchangeably with ‘Fecundity’ as they represent different life history parameters; (ii) provide a generalized redefinition of Fecundity selection that encompasses any traits that influence Fecundity in any direction (from high to low) and in either sex; (iii) review the (macro)ecological basis of Fecundity selection (e.g., ecological pressures that influence predictable spatial variation in Fecundity); (iv) suggest that most ecological theories of Fecundity selection should be tested in organisms other than birds; (v) argue that the longstanding Fecundity selection hypothesis of female-biased sexual size dimorphism (SSD) has gained inconsistent support, that strong Fecundity selection does not necessarily drive female-biased SSD, and that this form of SSD can be driven by other selective pressures; and (vi) discuss cases in which Fecundity selection operates on males.
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Fecundity Selection and the Evolution of Reproductive Output and Sex-Specific Body Size in the Liolaemus Lizard Adaptive Radiation
Evolutionary Biology, 2011Co-Authors: Daniel Pincheira-donoso, Tom TregenzaAbstract:Fecundity is a primary component of fitness. Theory predicts that the evolution of Fecundity through increased brood size results from Fecundity selection favouring larger female size to accommodate more offspring and to store more energy. This is expected to generate asymmetric selection on body size between the sexes, ultimately driving evolution of female-biased sexual size dimorphism. Additionally, it has been predicted that the intensity of Fecundity selection increases when the opportunities for reproduction are reduced by the limiting thermal effects of increasing latitude-elevation (i.e. decreasing environmental temperatures) on the length of the reproductive season. This later factor would be particularly strong among ectotherms, where reproduction is heavily temperature-dependent. However, this integrative perspective on reproductive evolution by Fecundity selection has rarely been investigated. Here, we employ a comparative approach to investigate these predictions in Liolaemus , a prominent lizard radiation. As expected, Liolaemus reproductive output (i.e. offspring number per reproductive episode) increases predictably with increasing female size. However, contrary to predictions, we found that increased Fecundity does not translate into female-biased SSD, and that combined latitude-elevation does not impose a detectable effect on Fecundity. Finally, our allometric analyses reveal that SSD scales with body size, which supports the occurrence of Rensch’s rule in these lizards. We discuss the evolutionary implications of our results, and the assumptions of the investigated hypotheses.
Richard C. Grandison - One of the best experts on this subject based on the ideXlab platform.
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amino acid imbalance explains extension of lifespan by dietary restriction in drosophila
Nature, 2009Co-Authors: Richard C. Grandison, Matthew D W Piper, Linda PartridgeAbstract:In a number of organisms, dietary restriction has been shown to extend lifespan at the expense of reduced Fecundity. An example of competition for limited resources, the thinking generally goes, as nutrients are reallocated from reproduction to somatic maintenance. Grandison et al. now demonstrate that, in Drosophila, dietary restriction does not induce reallocation, because different amino acids limit lifespan and Fecundity. They find that Fecundity in long-life flies can be rescued by the addition of methionine alone. Long lifespan and high Fecundity can thus occur simultaneously, without dietary restriction itself, by adjustment of the ratio of amino acids in the diet. These findings imply that humans might be able to enjoy the benefits of reduced food intake, without the downsides, by adjustment of dietary nutrients. Dietary restriction extends healthy lifespan in diverse organisms but reduces Fecundity; this is thought to be because of an adaptive reallocation of nutrients from reproduction to somatic maintenance. Here, the nutrients producing the responses of lifespan and Fecundity to dietary restriction in Drosophila are identified. Adding essential amino acids to the dietary restriction condition increased Fecundity and decreased lifespan; furthermore, addition of methionine alone rescued Fecundity. Dietary restriction extends healthy lifespan in diverse organisms and reduces Fecundity1,2. It is widely assumed to induce adaptive reallocation of nutrients from reproduction to somatic maintenance, aiding survival of food shortages in nature3,4,5,6. If this were the case, long life under dietary restriction and high Fecundity under full feeding would be mutually exclusive, through competition for the same limiting nutrients. Here we report a test of this idea in which we identified the nutrients producing the responses of lifespan and Fecundity to dietary restriction in Drosophila. Adding essential amino acids to the dietary restriction condition increased Fecundity and decreased lifespan, similar to the effects of full feeding, with other nutrients having little or no effect. However, methionine alone was necessary and sufficient to increase Fecundity as much as did full feeding, but without reducing lifespan. Reallocation of nutrients therefore does not explain the responses to dietary restriction. Lifespan was decreased by the addition of amino acids, with an interaction between methionine and other essential amino acids having a key role. Hence, an imbalance in dietary amino acids away from the ratio optimal for reproduction shortens lifespan during full feeding and limits Fecundity during dietary restriction. Reduced activity of the insulin/insulin-like growth factor signalling pathway extends lifespan in diverse organisms7, and we find that it also protects against the shortening of lifespan with full feeding. In other organisms, including mammals, it may be possible to obtain the benefits to lifespan of dietary restriction without incurring a reduction in Fecundity, through a suitable balance of nutrients in the diet.
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Amino-acid imbalance explains extension of lifespan by dietary restriction in Drosophila
Nature, 2009Co-Authors: Richard C. Grandison, Matthew D W Piper, Linda PartridgeAbstract:Dietary restriction extends healthy lifespan in diverse organisms and reduces Fecundity(1,2). It is widely assumed to induce adaptive reallocation of nutrients from reproduction to somatic maintenance, aiding survival of food shortages in nature(3-6). If this were the case, long life under dietary restriction and high Fecundity under full feeding would be mutually exclusive, through competition for the same limiting nutrients. Here we report a test of this idea in which we identified the nutrients producing the responses of lifespan and Fecundity to dietary restriction in Drosophila. Adding essential amino acids to the dietary restriction condition increased Fecundity and decreased lifespan, similar to the effects of full feeding, with other nutrients having little or no effect. However, methionine alone was necessary and sufficient to increase Fecundity as much as did full feeding, but without reducing lifespan. Reallocation of nutrients therefore does not explain the responses to dietary restriction. Lifespan was decreased by the addition of amino acids, with an interaction between methionine and other essential amino acids having a key role. Hence, an imbalance in dietary amino acids away from the ratio optimal for reproduction shortens lifespan during full feeding and limits Fecundity during dietary restriction. Reduced activity of the insulin/insulin-like growth factor signalling pathway extends lifespan in diverse organisms(7), and we find that it also protects against the shortening of lifespan with full feeding. In other organisms, including mammals, it may be possible to obtain the benefits to lifespan of dietary restriction without incurring a reduction in Fecundity, through a suitable balance of nutrients in the diet.
Kenyon B Mobley - One of the best experts on this subject based on the ideXlab platform.
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female ornamentation and the Fecundity trade off in a sex role reversed pipefish
Ecology and Evolution, 2018Co-Authors: Kenyon B Mobley, John R Morrongiello, Matthew Warr, Dianne J Bray, Bob B M WongAbstract:Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female ornamentation and Fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width, and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female Fecundity. Rather, females that have larger ornaments have higher Fecundity and thus accurately advertise their reproductive value to males without incurring a cost to Fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffer a slight decrease in egg size and Fecundity, although this decrease was independent of female ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent Fecundity cost of ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female ornamentation.
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female ornamentation and the Fecundity trade off in a sex role reversed pipefish
bioRxiv, 2018Co-Authors: Kenyon B Mobley, John R Morrongiello, Matthew Warr, Dianne J Bray, Bob B M WongAbstract:Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female ornamentation and Fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female Fecundity. Rather, females that have larger ornaments have higher Fecundity and thus accurately advertise their reproductive value to males without incurring a cost to Fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffered a slight decrease in egg size and Fecundity, although this decrease was independent of female ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent Fecundity cost of ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female ornamentation.
