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Michael C. Moore - One of the best experts on this subject based on the ideXlab platform.
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immune activity suppresses reproduction in food limited female tree lizards Urosaurus ornatus
Functional Ecology, 2007Co-Authors: Susannah S. French, Gwynne I. H. Johnston, Michael C. MooreAbstract:Summary 1When resources are scarce, organisms are faced with critical challenges trying to optimize competing functions. Reproduction and immune function are both resource intensive and important to most species. Most studies have reported a down-regulation of immune function during reproduction. Conversely, it is unclear whether mounting an immune response can affect the reproductive process and few studies have examined competition for resources between these two processes. 2Here we report evidence for direct competition for resources between the reproductive and immune systems in a vertebrate model system, the tree lizard (Urosaurus ornatus). We manipulated food intake in reproductive female tree lizards, where half of the females were undergoing cutaneous wound healing and the other half were not. We then measured reproductive investment in all animals and wound healing rate in all wounded animals. 3We found that animals with unlimited access to food sustained both reproduction and immune function whereas animals maintained on a restricted diet were not. Specifically, when food was unlimited, females were able to invest in reproduction and heal their wounds. However, when food was limited, females forced to heal a cutaneous wound had significantly smaller follicles than their non-wounded counterparts. Under extreme food limitation (i.e. no food) both reproductive investment and wound healing were suppressed. 4These results clearly demonstrate resource competition between the reproductive and immune systems, whereby physiological trade-offs between the two systems only arise when resources are limiting. Furthermore, this type of facultative regulation is adjustable and allows animals to respond to changing environmental conditions.
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Trade-offs between the reproductive and immune systems: facultative responses to resources or obligate responses to reproduction?
The American naturalist, 2007Co-Authors: Susannah S. French, Dale F. Denardo, Michael C. MooreAbstract:Abstract: A major challenge in biology is understanding how organisms partition limited resources among physiological processes. For example, offspring production and self‐maintenance are important for fitness and survival, yet these critical processes often compete for resources. While physiological trade‐offs between reproduction and immune function have been documented, their regulation remains unclear. Most current evidence suggests that physiological changes during specific reproductive states directly suppress various components of the immune system; however, some studies have not found this clear relationship. We performed two experiments in female tree lizards (Urosaurus ornatus) that demonstrate the presence of trade‐offs between the reproductive and immune systems under controlled laboratory conditions. These results also support the hypothesis that these trade‐offs are a facultative response to resource availability and are not obligatory responses to physiological changes during reproduction. ...
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Immune activity suppresses reproduction in food‐limited female tree lizards Urosaurus ornatus
Functional Ecology, 2007Co-Authors: Susannah S. French, Gwynne I. H. Johnston, Michael C. MooreAbstract:Summary 1When resources are scarce, organisms are faced with critical challenges trying to optimize competing functions. Reproduction and immune function are both resource intensive and important to most species. Most studies have reported a down-regulation of immune function during reproduction. Conversely, it is unclear whether mounting an immune response can affect the reproductive process and few studies have examined competition for resources between these two processes. 2Here we report evidence for direct competition for resources between the reproductive and immune systems in a vertebrate model system, the tree lizard (Urosaurus ornatus). We manipulated food intake in reproductive female tree lizards, where half of the females were undergoing cutaneous wound healing and the other half were not. We then measured reproductive investment in all animals and wound healing rate in all wounded animals. 3We found that animals with unlimited access to food sustained both reproduction and immune function whereas animals maintained on a restricted diet were not. Specifically, when food was unlimited, females were able to invest in reproduction and heal their wounds. However, when food was limited, females forced to heal a cutaneous wound had significantly smaller follicles than their non-wounded counterparts. Under extreme food limitation (i.e. no food) both reproductive investment and wound healing were suppressed. 4These results clearly demonstrate resource competition between the reproductive and immune systems, whereby physiological trade-offs between the two systems only arise when resources are limiting. Furthermore, this type of facultative regulation is adjustable and allows animals to respond to changing environmental conditions.
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The effects of stress on wound healing in male tree lizards (Urosaurus ornatus).
General and comparative endocrinology, 2005Co-Authors: Susannah S. French, Kathleen S. Matt, Michael C. MooreAbstract:Exposure to stress can aVect an organism’s partitioning of resources among immune function and other organismal functions. However, measuring immune function is often diYcult. Recent studies show that the rate of cutaneous wound healing in laboratory rodents is a simple, integrated measure of stress-sensitive immune function. We investigated the use of this technique in tree lizards to test the hypotheses (1) that stress compromises wound healing and (2) that this eVect is at least partially mediated by corticosterone. Laboratoryhoused male tree lizards randomly assigned to the experimental and control treatment groups received a 3.5 mm cutaneous biopsy on the dorsal surface of the pelvis. Experimental group males were restrained in cloth bags for 60 min every day for 21 days during the healing proWle, whereas control males were left in their cages. Wound sizes were measured every other day by image analysis. Control animals healed faster than stressed animals. The diVerence in wound surface area between the groups was most pronounced early in the healing proWle. Stressed animals also had higher corticosterone levels and corticosterone was negatively correlated with healing rate in the stressed animals. These observations support both hypotheses that stress compromises healing and that corticosterone may act to mediate the eVects of stress.
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Plasma corticosterone response to an acute stressor varies according to reproductive condition in female tree lizards (Urosaurus ornatus).
General and comparative endocrinology, 2002Co-Authors: Sarah K. Woodley, Michael C. MooreAbstract:The magnitude of the glucocorticoid response to a stressor can depend on both environmental and physiological context. One factor that has not been examined is whether females of different reproductive states have different responses to a stressor. We examined whether corticosterone (CORT) increased after a 10 min handling stress in oviparous female tree lizards (Urosaurus ornatus) that were vitellogenic (yolking follicles) or gravid (post-ovulatory). We found that stressed vitellogenic females had a large increase in plasma CORT whereas gravid females did not. Baseline levels of CORT in gravid females were relatively high and similar to those in stressed vitellogenic females. The lack of a stress response in gravid females may be due to an inability to secrete higher levels of CORT or a suppression of the stress response. In addition, within vitellogenic females, CORT was positively correlated with ovarian weight, suggesting that CORT may function in some aspect of ovarian development during vitellogenesis.
Gregory J. Haenel - One of the best experts on this subject based on the ideXlab platform.
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Introgression of mtDNA in Urosaurus lizards: historical and ecological processes.
Molecular ecology, 2016Co-Authors: Gregory J. HaenelAbstract:Introgression of mtDNA appears common in animals but the implications of acquiring a novel mitochondrial genome are not well known. This study investigates mito-genome introgression between the lizard species Urosaurus graciosus, a thermal specialist, and U. ornatus, a species that occupies a wider range of thermal environments. As ectotherms, their metabolic rate is strongly influenced by the thermal environment; with mitochondria being linked to metabolic rates, overall energy budgets could be impacted by introgression. I use mitochondrial gene trees, inferred from Bayesian analyses of Cyt-B and ND1 gene sequences, along with morphology and microsatellites from nineteen populations of these two species to address if the direction and location of mito-nuclear discordance match predictions of introgression resulting from past population expansions. MtDNA is expected to move from resident species into expanding or invading species. Second, does having a heterospecific form of mitochondria impact body size, a trait strongly associated with fitness? Multiple independent introgression events of historic origin were detected. All introgression was unidirectional with U. ornatus-type mtDNA found in U. graciosus parental type individuals. This result was consistent with population expansions detected in U. graciosus but not U. ornatus. Females with heterospecific mtDNA were significantly smaller than homospecific forms and heterospecific males had a different relationship of body mass to body length than those with homospecific mtDNA. These changes indicate a potential selective disadvantage for individuals with heterospecific mitochondria and are consistent with the theoretical expectation that deleterious alleles are more likely to persist in expanding populations. This article is protected by copyright. All rights reserved.
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Effects of habitat on clutch size of ornate tree lizards, Urosaurus ornatus
Western North American Naturalist, 2011Co-Authors: Gregory J. HaenelAbstract:ABSTRACT. Clutch size is an important determinant of female reproductive success in reptiles. Although female body size explains much variation in clutch size, other important factors include differences in food availability, predation risk, morphology, and demography. Ornate tree lizards, Urosaurus ornatus, display extensive variation in life history traits, including clutch size. Tree lizards primarily use 2 distinct habitat types—trees and rock surfaces—which influence both the performance and morphology of this species and may affect life history traits such as clutch size. As food availability, microclimate, and, potentially, predator escape probabilities differ between these 2 habitats, I predicted that tree- and rockdwelling lizards would allocate resources toward clutch size differently. Clutch size variation was compared among 15 populations of U. ornatus sampled from the different habitat types. Urosaurus ornatus individuals living on trees had significantly larger clutches than those living on ...
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Isolation and characterization of microsatellite markers in tree lizards (Urosaurus ornatus).
Molecular ecology resources, 2009Co-Authors: Gregory J. HaenelAbstract:Tree lizards (Urosaurus ornatus) are a highly accessible species useful in testing theories of life-history evolution and behavioural ecology. A polymerase chain reaction-based method was used to isolate nine polymorphic tetranucleotide microsatellite loci from the genome of these lizards. The isolated loci displayed 5 to 9 alleles in the populations screened. Observed heterozygosity ranged from 0.333 to 0.900. Results indicate these loci now provide a basis to study mate choice, parentage, and population genetic structure within this species.
M. C. Moore - One of the best experts on this subject based on the ideXlab platform.
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© 2007 The Authors. Journal compilation © 2007 British Ecological
2007Co-Authors: S. S. French, G. I. H. Johnston, M. C. MooreAbstract:Blackwell Publishing LtdImmune activity suppresses reproduction in food-limited female tree lizards ( Urosaurus ornatu
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Social, environmental and genetic factors in the ontogeny of phenotypic differentiation in a lizard with alternative male reproductive strategies
Behavioral Ecology and Sociobiology, 1993Co-Authors: C. W. Thompson, I. T. Moore, M. C. MooreAbstract:Adult male tree lizards, Urosaurus ornatus , practise alternative (territorial or sneaker/satellite) reproductive strategies that are correlated with differences in throat color and body size. In this study we raised tree lizards from hatching in the laboratory to examine the question of whether the phenotypic expression of secondary sex coloration and body size can be facultatively influenced by social or abiotic environmental factors. We compared males reared in the laboratory under different social and environmental conditions to males in the field and found no effect of different conditions on phenotypic differentiation (Figs. 2–4). Thus, phenotypic differences between morphs probably result largely from nonfacultative expression of different genotypes. This suggests that alternative male morphs practise a mixed evolutionary stable strategy (ESS) rather than one morph making the best of a bad situation. However, in the context of ESS theory it is difficult to explain our further result that the nonterritorial morph in this species grows faster and reaches a larger adult body size than the territorial morph (Fig. 5).
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Social, environmental and genetic factors in the ontogeny of phenotypic differentiation in a lizard with alternative male reproductive strategies
Behavioral Ecology and Sociobiology, 1993Co-Authors: C. W. Thompson, I. T. Moore, M. C. MooreAbstract:Adult male tree lizards, Urosaurus ornatus , practise alternative (territorial or sneaker/satellite) reproductive strategies that are correlated with differences in throat color and body size. In this study we raised tree lizards from hatching in the laboratory to examine the question of whether the phenotypic expression of secondary sex coloration and body size can be facultatively influenced by social or abiotic environmental factors. We compared males reared in the laboratory under different social and environmental conditions to males in the field and found no effect of different conditions on phenotypic differentiation (Figs. 2–4). Thus, phenotypic differences between morphs probably result largely from nonfacultative expression of different genotypes. This suggests that alternative male morphs practise a mixed evolutionary stable strategy (ESS) rather than one morph making the best of a bad situation. However, in the context of ESS theory it is difficult to explain our further result that the nonterritorial morph in this species grows faster and reaches a larger adult body size than the territorial morph (Fig. 5).
Bieke Vanhooydonck - One of the best experts on this subject based on the ideXlab platform.
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Divergent roles for multiple sexual signals in a polygynous lizard
Functional Ecology, 2006Co-Authors: Jay J. Meyers, Bieke Vanhooydonck, Duncan J. Irschick, Anthony HerrelAbstract:Summary 1 An unresolved issue in sexual selection concerns the utility of multiple sexual signals that are used simultaneously during displays. We examined male lizards (Urosaurus ornatus) that exhibit two colourful ornaments (throat patch and belly patch) during territorial displays. Populations of Urosaurus ornatus can be polymorphic in throat coloration, and previous studies have shown that the morphs differ in behavioural aggression. We assume that throat coloration correlates with behavioural aggression in our population, as for other populations of U. ornatus. 2 We show that these different morphs do not differ significantly in morphological shape or bite force, a key aspect of fighting capacity. However, by contrast, the size of the belly patch is a significant predictor of maximum bite force, which is a predictor of dominance in other lizards. 3 We suggest that belly patch size and throat patch coloration are largely exclusive in that dominant individuals can exhibit small belly patches and low bite forces, whereas subordinate individuals can have large belly patches and high bite forces. Thus, embedded within the same male lizard display are divergent sexual structures that signal different traits, implying that the possession of multiple sexual signals within animals may be favoured by selection.
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correlations between habitat use and body shape in a phrynosomatid lizard Urosaurus ornatus a population level analysis
Biological Journal of The Linnean Society, 2001Co-Authors: Anthony Herrel, Jay J. Meyers, Bieke VanhooydonckAbstract:Abstract Recent ecomorphological studies have shown that the predicted correlations between morphology and ecology on broad taxonomic levels are often obscured when comparing more closely related groups. Among species, comparisons of lizards often indicate very little support for adaptive radiations into novel habitats. As few population level studies have been performed, we compared body, head and limb shape between four populations of Urosaurus ornatus living in structurally distinct habitats (cliffs, rocks, trees and boulders). Surprisingly, clear correlations between habitat use and body shape among populations were found, most of which were in good accordance with a priori biomechanical predictions (e.g. flat body and head for extreme climbers; long distal hindlimb segments for jumpers and runners; narrow body and long tail for tree dwelling lizards). This indicates that populations of Urosaurus ornatus are seemingly «adapted» to the habitat they live in. However, quantification of performance and behaviour are needed to determine the adaptive nature of these observations.
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Correlations between habitat use and body shape in a phrynosomatid lizard (Urosaurus ornatus): a population‐level analysis
Biological Journal of the Linnean Society, 2001Co-Authors: Anthony Herrel, Jay J. Meyers, Bieke VanhooydonckAbstract:Abstract Recent ecomorphological studies have shown that the predicted correlations between morphology and ecology on broad taxonomic levels are often obscured when comparing more closely related groups. Among species, comparisons of lizards often indicate very little support for adaptive radiations into novel habitats. As few population level studies have been performed, we compared body, head and limb shape between four populations of Urosaurus ornatus living in structurally distinct habitats (cliffs, rocks, trees and boulders). Surprisingly, clear correlations between habitat use and body shape among populations were found, most of which were in good accordance with a priori biomechanical predictions (e.g. flat body and head for extreme climbers; long distal hindlimb segments for jumpers and runners; narrow body and long tail for tree dwelling lizards). This indicates that populations of Urosaurus ornatus are seemingly «adapted» to the habitat they live in. However, quantification of performance and behaviour are needed to determine the adaptive nature of these observations.
Susannah S. French - One of the best experts on this subject based on the ideXlab platform.
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immune activity suppresses reproduction in food limited female tree lizards Urosaurus ornatus
Functional Ecology, 2007Co-Authors: Susannah S. French, Gwynne I. H. Johnston, Michael C. MooreAbstract:Summary 1When resources are scarce, organisms are faced with critical challenges trying to optimize competing functions. Reproduction and immune function are both resource intensive and important to most species. Most studies have reported a down-regulation of immune function during reproduction. Conversely, it is unclear whether mounting an immune response can affect the reproductive process and few studies have examined competition for resources between these two processes. 2Here we report evidence for direct competition for resources between the reproductive and immune systems in a vertebrate model system, the tree lizard (Urosaurus ornatus). We manipulated food intake in reproductive female tree lizards, where half of the females were undergoing cutaneous wound healing and the other half were not. We then measured reproductive investment in all animals and wound healing rate in all wounded animals. 3We found that animals with unlimited access to food sustained both reproduction and immune function whereas animals maintained on a restricted diet were not. Specifically, when food was unlimited, females were able to invest in reproduction and heal their wounds. However, when food was limited, females forced to heal a cutaneous wound had significantly smaller follicles than their non-wounded counterparts. Under extreme food limitation (i.e. no food) both reproductive investment and wound healing were suppressed. 4These results clearly demonstrate resource competition between the reproductive and immune systems, whereby physiological trade-offs between the two systems only arise when resources are limiting. Furthermore, this type of facultative regulation is adjustable and allows animals to respond to changing environmental conditions.
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Trade-offs between the reproductive and immune systems: facultative responses to resources or obligate responses to reproduction?
The American naturalist, 2007Co-Authors: Susannah S. French, Dale F. Denardo, Michael C. MooreAbstract:Abstract: A major challenge in biology is understanding how organisms partition limited resources among physiological processes. For example, offspring production and self‐maintenance are important for fitness and survival, yet these critical processes often compete for resources. While physiological trade‐offs between reproduction and immune function have been documented, their regulation remains unclear. Most current evidence suggests that physiological changes during specific reproductive states directly suppress various components of the immune system; however, some studies have not found this clear relationship. We performed two experiments in female tree lizards (Urosaurus ornatus) that demonstrate the presence of trade‐offs between the reproductive and immune systems under controlled laboratory conditions. These results also support the hypothesis that these trade‐offs are a facultative response to resource availability and are not obligatory responses to physiological changes during reproduction. ...
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Immune activity suppresses reproduction in food‐limited female tree lizards Urosaurus ornatus
Functional Ecology, 2007Co-Authors: Susannah S. French, Gwynne I. H. Johnston, Michael C. MooreAbstract:Summary 1When resources are scarce, organisms are faced with critical challenges trying to optimize competing functions. Reproduction and immune function are both resource intensive and important to most species. Most studies have reported a down-regulation of immune function during reproduction. Conversely, it is unclear whether mounting an immune response can affect the reproductive process and few studies have examined competition for resources between these two processes. 2Here we report evidence for direct competition for resources between the reproductive and immune systems in a vertebrate model system, the tree lizard (Urosaurus ornatus). We manipulated food intake in reproductive female tree lizards, where half of the females were undergoing cutaneous wound healing and the other half were not. We then measured reproductive investment in all animals and wound healing rate in all wounded animals. 3We found that animals with unlimited access to food sustained both reproduction and immune function whereas animals maintained on a restricted diet were not. Specifically, when food was unlimited, females were able to invest in reproduction and heal their wounds. However, when food was limited, females forced to heal a cutaneous wound had significantly smaller follicles than their non-wounded counterparts. Under extreme food limitation (i.e. no food) both reproductive investment and wound healing were suppressed. 4These results clearly demonstrate resource competition between the reproductive and immune systems, whereby physiological trade-offs between the two systems only arise when resources are limiting. Furthermore, this type of facultative regulation is adjustable and allows animals to respond to changing environmental conditions.
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The effects of stress on wound healing in male tree lizards (Urosaurus ornatus).
General and comparative endocrinology, 2005Co-Authors: Susannah S. French, Kathleen S. Matt, Michael C. MooreAbstract:Exposure to stress can aVect an organism’s partitioning of resources among immune function and other organismal functions. However, measuring immune function is often diYcult. Recent studies show that the rate of cutaneous wound healing in laboratory rodents is a simple, integrated measure of stress-sensitive immune function. We investigated the use of this technique in tree lizards to test the hypotheses (1) that stress compromises wound healing and (2) that this eVect is at least partially mediated by corticosterone. Laboratoryhoused male tree lizards randomly assigned to the experimental and control treatment groups received a 3.5 mm cutaneous biopsy on the dorsal surface of the pelvis. Experimental group males were restrained in cloth bags for 60 min every day for 21 days during the healing proWle, whereas control males were left in their cages. Wound sizes were measured every other day by image analysis. Control animals healed faster than stressed animals. The diVerence in wound surface area between the groups was most pronounced early in the healing proWle. Stressed animals also had higher corticosterone levels and corticosterone was negatively correlated with healing rate in the stressed animals. These observations support both hypotheses that stress compromises healing and that corticosterone may act to mediate the eVects of stress.