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Full-Text Articles in Life Sciences
Species-Specific Means And Within-Species Variance In Glucocorticoid Hormones And Speciation Rates In Birds, L. Z. Garamszegi, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams
Species-Specific Means And Within-Species Variance In Glucocorticoid Hormones And Speciation Rates In Birds, L. Z. Garamszegi, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams
Biology Faculty Research
At macroevolutionary scales, stress physiology may have consequences for species diversification and subspecies richness. Populations that exploit new resources or undergo range expansion should cope with new environmental challenges, which could favor higher mean stress responses. Within-species variation in the stress response may also play a role in mediating the speciation process: in species with broad variation, there will always be some individuals that can tolerate an unpredictable environment, whereas in species with narrow variation there will be fewer individuals that are able to thrive in a new ecological niche. We tested for the evolutionary relationship between stress response, speciation …
Standing Variation And The Capacity For Change: Are Endocrine Phenotypes More Variable That Other Traits?, M. C. Miles, Maren N. Vitousek, Jerry F. Husak, Michele A. Johnson, L. B. Martin, C. C. Taff, C. Zimmer, M. B. Lovern, M. J. Fuxjager
Standing Variation And The Capacity For Change: Are Endocrine Phenotypes More Variable That Other Traits?, M. C. Miles, Maren N. Vitousek, Jerry F. Husak, Michele A. Johnson, L. B. Martin, C. C. Taff, C. Zimmer, M. B. Lovern, M. J. Fuxjager
Biology Faculty Research
Circulating steroid hormone levels exhibit high variation both within and between individuals, leading some to hypothesize that these phenotypes are more variable than other morphological, physiological, and behavioral traits. This should have profound implications for the evolution of steroid signaling systems, but few studies have examined how endocrine variation compares to that of other traits or differs among populations. Here we provide such an analysis by first exploring how variation in three measures of corticosterone (CORT)—baseline, stress-induced, and post-dexamethasone injection—compares to variation in key traits characterizing morphology (wing length, mass), physiology (reactive oxygen metabolite concentration [d-ROMs] and antioxidant capacity), and …
Metabolic Scaling Of Stress Hormones In Vertebrates, C. D. Francis, Jeremy W. Donald, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, C. J. Downs
Metabolic Scaling Of Stress Hormones In Vertebrates, C. D. Francis, Jeremy W. Donald, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, C. J. Downs
Biology Faculty Research
Glucocorticoids (GCs) are stress hormones that can strongly influence physiology, behavior, and an organism’s ability to cope with environmental change. Despite their importance, and the wealth of studies that have sought to understand how and why GC concentrations vary within species, we do not have a clear understanding of how circulating GC levels vary within and across the major vertebrate clades. New research has proposed that much interspecific variation in GC concentrations can be explained by variation in metabolism and body mass. Specifically, GC concentrations should vary proportionally with mass-specific metabolic rates and, given known scaling relationships between body mass …
Do Seasonal Glucocorticoid Changes Depend On Reproductive Investment? A Comparative Approach In Birds, S. Casagrande, L. Z. Garamszegi, W. Goymann, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, M. Hau
Do Seasonal Glucocorticoid Changes Depend On Reproductive Investment? A Comparative Approach In Birds, S. Casagrande, L. Z. Garamszegi, W. Goymann, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, M. Hau
Biology Faculty Research
Animals go through different life history stages such as reproduction, moult, or migration, of which some are more energy-demanding than others. Baseline concentrations of glucocorticoid hormones increase during moderate, predictable challenges and thus are expected to be higher when seasonal energy demands increase, such as during reproduction. By contrast, stress-induced glucocorticoids prioritize a survival mode that includes reproductive inhibition. Thus, many species down-regulate stress-induced glucocorticoid concentrations during the breeding season. Interspecific variation in glucocorticoid levels during reproduction has been successfully mapped onto reproductive investment, with species investing strongly in current reproduction (fast pace of life) showing higher baseline and lower …
Iucn Conservation Status Does Not Predict Glucocortoid Concentrations In Reptiles And Birds, L. B. Martin, Maren N. Vitousek, Jeremy W. Donald, T. Flock, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, E. T. Miller, L. A. Schoenle, T. D. Williams, C. D. Francis
Iucn Conservation Status Does Not Predict Glucocortoid Concentrations In Reptiles And Birds, L. B. Martin, Maren N. Vitousek, Jeremy W. Donald, T. Flock, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, E. T. Miller, L. A. Schoenle, T. D. Williams, C. D. Francis
Biology Faculty Research
Circulating glucocorticoids (GCs) are the most commonly used biomarkers of stress in wildlife. However, their utility as a tool for identifying and/or managing at-risk species has varied. Here, we took a very broad approach to conservation physiology, asking whether International Union for the Conservation of Nature (IUCN) listing status (concern versus no obvious concern) and/or location within a geographic range (edge versus non-edge) predicted baseline and post-restraint concentrations of corticosterone (CORT) among many species of birds and reptiles. Even though such an approach can be viewed as coarse, we asked in this analysis whether CORT concentrations might be useful to …
Carotenoid-Based Ornaments Of Female And Male American Goldfinches (Spinus Tristis) Show Sex-Specific Correlations With Immune Function And Metabolic Rate, R. J. Kelly, Troy G. Murphy, K. A. Tarvin, G. Burness
Carotenoid-Based Ornaments Of Female And Male American Goldfinches (Spinus Tristis) Show Sex-Specific Correlations With Immune Function And Metabolic Rate, R. J. Kelly, Troy G. Murphy, K. A. Tarvin, G. Burness
Biology Faculty Research
Conspicuous ornamentation has been linked to immunological and physiological condition in males of many species. In species where both sexes are ornamented, it is unclear whether the signal content of ornaments differs between males and females. We examined the immunological and physiological correlates of carotenoid-based bill and plumage ornamentation in American goldfinches Spinus tristis, a species in which bright orange bills are sexually monomorphic but yellow plumage is sexually dimorphic during the breeding season. Because bill color is dynamic over short periods while plumage color is static over longer time frames, we tested whether these signals have the potential to …
Ampk Directly Inhibits Ndpk Through A Phosphoserine Switch To Maintain Cellular Homeostasis, R. U. Onyenwoke, L. J. Forsberg, L. Liu, Tyisha Williams, O. Alzate, J. E. Brenman
Ampk Directly Inhibits Ndpk Through A Phosphoserine Switch To Maintain Cellular Homeostasis, R. U. Onyenwoke, L. J. Forsberg, L. Liu, Tyisha Williams, O. Alzate, J. E. Brenman
Biology Faculty Research
AMP-activated protein kinase (AMPK) is a key energy sensor that regulates metabolism to maintain cellular energy balance. AMPK activation has also been proposed to mimic benefits of caloric restriction and exercise. Therefore, identifying downstream AMPK targets could elucidate new mechanisms for maintaining cellular energy homeostasis. We identified the phosphotransferase nucleoside diphosphate kinase (NDPK), which maintains pools of nucleotides, as a direct AMPK target through the use of two-dimensional differential in-gel electrophoresis. Furthermore, we mapped the AMPK/NDPK phosphorylation site (serine 120) as a functionally potent enzymatic “off switch” both in vivo and in vitro. Because ATP is usually the most abundant …
Identification Of A Nuclear Export Signal In The Catalytic Subunit Of Amp-Activated Protein Kinase, N. Kazgan, Tyisha Williams, L. J. Forsberg, J. E. Brenman
Identification Of A Nuclear Export Signal In The Catalytic Subunit Of Amp-Activated Protein Kinase, N. Kazgan, Tyisha Williams, L. J. Forsberg, J. E. Brenman
Biology Faculty Research
The metabolic regulator AMP-activated protein kinase (AMPK) maintains cellular homeostasis through regulation of proteins involved in energy-producing and -consuming pathways. Although AMPK phosphorylation targets include cytoplasmic and nuclear proteins, the precise mechanisms that regulate AMPK localization, and thus its access to these substrates, are unclear. We identify highly conserved carboxy-terminal hydrophobic amino acids that function as a leptomycin B–sensitive, CRM1-dependent nuclear export sequence (NES) in the AMPK catalytic subunit (AMPKα). When this sequence is modified AMPKα shows increased nuclear localization via a Ran-dependent import pathway. Cytoplasmic localization can be restored by substituting well-defined snurportin-1 or protein kinase A inhibitor (PKIA) …