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Mangiamele LA, Dawn A, LeCure KM, Mantica GE, Racicot R, Fuxjager MJ, Preininger D. How new communication behaviors evolve: Androgens as modifiers of neuromotor structure and function in foot-flagging frogs. Horm Behav 2024; 161:105502. [PMID: 38382227 DOI: 10.1016/j.yhbeh.2024.105502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/08/2023] [Accepted: 02/05/2024] [Indexed: 02/23/2024]
Abstract
How diverse animal communication signals have arisen is a question that has fascinated many. Xenopus frogs have been a model system used for three decades to reveal insights into the neuroendocrine mechanisms and evolution of vocal diversity. Due to the ease of studying central nervous system control of the laryngeal muscles in vitro, Xenopus has helped us understand how variation in vocal communication signals between sexes and between species is produced at the molecular, cellular, and systems levels. Yet, it is becoming easier to make similar advances in non-model organisms. In this paper, we summarize our research on a group of frog species that have evolved a novel hind limb signal known as 'foot flagging.' We have previously shown that foot flagging is androgen dependent and that the evolution of foot flagging in multiple unrelated species is accompanied by the evolution of higher androgen hormone sensitivity in the leg muscles. Here, we present new preliminary data that compare patterns of androgen receptor expression and neuronal cell density in the lumbar spinal cord - the neuromotor system that controls the hind limb - between foot-flagging and non-foot-flagging frog species. We then relate our work to prior findings in Xenopus, highlighting which patterns of hormone sensitivity and neuroanatomical structure are shared between the neuromotor systems underlying Xenopus vocalizations and foot-flagging frogs' limb movement and which appear to be species-specific. Overall, we aim to illustrate the power of drawing inspiration from experiments in model organisms, in which the mechanistic details have been worked out, and then applying these ideas to a non-model species to reveal new details, further complexities, and fresh hypotheses.
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Affiliation(s)
- Lisa A Mangiamele
- Department of Biological Sciences, Smith College, Northampton, MA 01063, United States of America.
| | - AllexAndrya Dawn
- Department of Biological Sciences, Smith College, Northampton, MA 01063, United States of America
| | - Kerry M LeCure
- Department of Biological Sciences, Smith College, Northampton, MA 01063, United States of America
| | - Gina E Mantica
- Department of Biological Sciences, Smith College, Northampton, MA 01063, United States of America
| | - Riccardo Racicot
- Department of Biological Sciences, Smith College, Northampton, MA 01063, United States of America
| | - Matthew J Fuxjager
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, United States of America
| | - Doris Preininger
- Department of Evolutionary Biology, University of Vienna, Vienna, Austria; Vienna Zoo, Vienna, Austria
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2
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Santicchia F, Tranquillo C, Wauters LA, Palme R, Panzeri M, Preatoni D, Bisi F, Martinoli A. Physiological stress response to urbanisation differs between native and invasive squirrel species. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:171336. [PMID: 38423339 DOI: 10.1016/j.scitotenv.2024.171336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/29/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024]
Abstract
Novel pressures derived from urbanisation can alter native habitats and ultimately impact wildlife. Coping with such human-driven changes might induce shifts in species phenotypic traits, such as physiological responses to anthropogenic stressors. Preadaptation to face those challenges has been suggested to favour settlement and spread of invasive alien species in urbanised areas which, consequently, might respond differently than ecologically similar native species to stressors posed by urbanisation. The activation of the hypothalamic-pituitary-adrenal (HPA) axis and the subsequent release of glucocorticoids (GCs) has been suggested to mediate responses to anthropogenic disturbance in vertebrates. Furthermore, intraspecific competition, in conjunction with stressors related to urbanisation, might affect invasive and native species physiological stress responses differently. Using a parallel pseudo-experimental study system we measured faecal glucocorticoid metabolite (FGM) concentrations of the native Eurasian red squirrel and the invasive alien Eastern grey squirrel along a rural-urban gradient and in relation to conspecific density. The two species responded differently to challenges posed by the synergic effect of urbanisation and intraspecific competition. Association of FGMs and conspecific density in native red squirrels varied between rural and suburban sites, potentially depending on differential HPA axis responses. In urban sites, this relationship did not differ significantly from that in rural and suburban ones. Conversely, invasive grey squirrels' FGMs did not vary in relation to conspecific density, nor differed along the rural-urban gradient. Improving knowledge about native and competing invasive species' physiological responses to anthropogenic stressors can support conservation strategies in habitats altered by man. Our findings suggested that the invasive squirrels might be preadapted to cope with these challenges in urbanised areas, potentially increasing their success under the future global change scenario.
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Affiliation(s)
- Francesca Santicchia
- Environment Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy.
| | - Claudia Tranquillo
- Environment Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy.
| | - Lucas A Wauters
- Environment Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy; Evolutionary Ecology Group, Department of Biology, University of Antwerp, Campus Drie Eiken Universiteitsplein 1, 2610 Wilrijk, Belgium.
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
| | - Mattia Panzeri
- Environment Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy
| | - Damiano Preatoni
- Environment Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy.
| | - Francesco Bisi
- Environment Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy.
| | - Adriano Martinoli
- Environment Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy.
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3
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Taff CC, Baldan D, Mentesana L, Ouyang JQ, Vitousek MN, Hau M. Endocrine flexibility can facilitate or constrain the ability to cope with global change. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220502. [PMID: 38310929 PMCID: PMC10838644 DOI: 10.1098/rstb.2022.0502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 11/21/2023] [Indexed: 02/06/2024] Open
Abstract
Global climate change has increased average environmental temperatures world-wide, simultaneously intensifying temperature variability and extremes. Growing numbers of studies have documented phenological, behavioural and morphological responses to climate change in wild populations. As systemic signals, hormones can contribute to orchestrating many of these phenotypic changes. Yet little is known about whether mechanisms like hormonal flexibility (reversible changes in hormone concentrations) facilitate or limit the ability of individuals, populations and species to cope with a changing climate. In this perspective, we discuss different mechanisms by which hormonal flexibility, primarily in glucocorticoids, could promote versus hinder evolutionary adaptation to changing temperature regimes. We focus on temperature because it is a key gradient influenced by climate change, it is easy to quantify, and its links to hormones are well established. We argue that reaction norm studies that connect individual responses to population-level and species-wide patterns will be critical for making progress in this field. We also develop a case study on urban heat islands, where several key questions regarding hormonal flexibility and adaptation to climate change can be addressed. Understanding the mechanisms that allow animals to cope when conditions become more challenging will help in predicting which populations are vulnerable to ongoing climate change. This article is part of the theme issue 'Endocrine responses to environmental variation: conceptual approaches and recent developments'.
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Affiliation(s)
- Conor C. Taff
- Laboratory Ornithology and Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Biology, Colby College, Waterville, ME 04901, USA
| | - Davide Baldan
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Lucia Mentesana
- Evolutionary Physiology, Max Planck Institute for Biological Intelligence, 82319 Seewiesen, Germany
- Faculty of Sciences, Republic University, Montevideo, 11200, Uruguay
| | - Jenny Q. Ouyang
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Maren N. Vitousek
- Laboratory Ornithology and Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Michaela Hau
- Evolutionary Physiology, Max Planck Institute for Biological Intelligence, 82319 Seewiesen, Germany
- Department of Biology, University of Konstanz, Konstanz, 78467, Germany
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4
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Bolton PE, Ryder TB, Dakin R, Houtz JL, Moore IT, Balakrishnan CN, Horton BM. Neurogenomic landscape associated with status-dependent cooperative behaviour. Mol Ecol 2024:e17327. [PMID: 38511765 DOI: 10.1111/mec.17327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/04/2024] [Accepted: 03/07/2024] [Indexed: 03/22/2024]
Abstract
The neurogenomic mechanisms mediating male-male reproductive cooperative behaviours remain unknown. We leveraged extensive transcriptomic and behavioural data on a neotropical bird species (Pipra filicauda) that performs cooperative courtship displays to understand these mechanisms. In this species, the cooperative display is modulated by testosterone, which promotes cooperation in non-territorial birds, but suppresses cooperation in territory holders. We sought to understand the neurogenomic underpinnings of three related traits: social status, cooperative display behaviour and testosterone phenotype. To do this, we profiled gene expression in 10 brain nuclei spanning the social decision-making network (SDMN), and two key endocrine tissues that regulate social behaviour. We associated gene expression with each bird's behavioural and endocrine profile derived from 3 years of repeated measures taken from free-living birds in the Ecuadorian Amazon. We found distinct landscapes of constitutive gene expression were associated with social status, testosterone phenotype and cooperation, reflecting the modular organization and engagement of neuroendocrine tissues. Sex-steroid and neuropeptide signalling appeared to be important in mediating status-specific relationships between testosterone and cooperation, suggesting shared regulatory mechanisms with male aggressive and sexual behaviours. We also identified differentially regulated genes involved in cellular activity and synaptic potentiation, suggesting multiple mechanisms underpin these genomic states. Finally, we identified SDMN-wide gene expression differences between territorial and floater males that could form the basis of 'status-specific' neurophysiological phenotypes, potentially mediated by testosterone and growth hormone. Overall, our findings provide new, systems-level insights into the mechanisms of cooperative behaviour and suggest that differences in neurogenomic state are the basis for individual differences in social behaviour.
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Affiliation(s)
- Peri E Bolton
- Department of Biology, East Carolina University, Greenville, North Carolina, USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, USA
| | - T Brandt Ryder
- Migratory Bird Center, Smithsonian National Zoological Park, Washington, District of Columbia, USA
- Bird Conservancy of the Rockies, Fort Collins, Colorado, USA
| | - Roslyn Dakin
- Migratory Bird Center, Smithsonian National Zoological Park, Washington, District of Columbia, USA
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Jennifer L Houtz
- Department of Biology, Millersville University, Millersville, Pennsylvania, USA
- Department of Biology, Allegheny College, Meadville, Pennsylvania, USA
| | - Ignacio T Moore
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | | | - Brent M Horton
- Department of Biology, Millersville University, Millersville, Pennsylvania, USA
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5
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Robinson CD, Hale MD, Wittman TN, Cox CL, John-Alder HB, Cox RM. Species differences in hormonally mediated gene expression underlie the evolutionary loss of sexually dimorphic coloration in Sceloporus lizards. J Hered 2023; 114:637-653. [PMID: 37498153 DOI: 10.1093/jhered/esad046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/24/2023] [Indexed: 07/28/2023] Open
Abstract
Phenotypic sexual dimorphism often involves the hormonal regulation of sex-biased expression for underlying genes. However, it is generally unknown whether the evolution of hormonally mediated sexual dimorphism occurs through upstream changes in tissue sensitivity to hormone signals, downstream changes in responsiveness of target genes, or both. Here, we use comparative transcriptomics to explore these possibilities in 2 species of Sceloporus lizards exhibiting different patterns of sexual dichromatism. Sexually dimorphic S. undulatus develops blue and black ventral coloration in response to testosterone, while sexually monomorphic S. virgatus does not, despite exhibiting similar sex differences in circulating testosterone levels. We administered testosterone implants to juveniles of each species and used RNAseq to quantify gene expression in ventral skin. Transcriptome-wide responses to testosterone were stronger in S. undulatus than in S. virgatus, suggesting species differences in tissue sensitivity to this hormone signal. Species differences in the expression of genes for androgen metabolism and sex hormone-binding globulin were consistent with this idea, but expression of the androgen receptor gene was higher in S. virgatus, complicating this interpretation. Downstream of androgen signaling, we found clear species differences in hormonal responsiveness of genes related to melanin synthesis, which were upregulated by testosterone in S. undulatus, but not in S. virgatus. Collectively, our results indicate that hormonal regulation of melanin synthesis pathways contributes to the development of sexual dimorphism in S. undulatus, and that changes in the hormonal responsiveness of these genes in S. virgatus contribute to the evolutionary loss of ventral coloration.
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Affiliation(s)
| | - Matthew D Hale
- University of Virginia, Department of Biology, Charlottesville, VA, United States
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine Inc., Bethesda, MD, United States
| | - Tyler N Wittman
- University of Virginia, Department of Biology, Charlottesville, VA, United States
| | - Christian L Cox
- Florida International University, Department of Biological Sciences and Institute of Environment, Miami, FL, United States
| | - Henry B John-Alder
- Rutgers University, Department of Ecology, Evolution, and Natural Resources, New Brunswick, NJ, United States
| | - Robert M Cox
- University of Virginia, Department of Biology, Charlottesville, VA, United States
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6
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Abstract
Endocrine signaling networks control diverse biological processes and life history traits across metazoans. In both invertebrate and vertebrate taxa, steroid hormones regulate immune system function in response to intrinsic and environmental stimuli, such as microbial infection. The mechanisms of this endocrine-immune regulation are complex and constitute an ongoing research endeavor facilitated by genetically tractable animal models. The 20-hydroxyecdysone (20E) is the major steroid hormone in arthropods, primarily studied for its essential role in mediating developmental transitions and metamorphosis; 20E also modulates innate immunity in a variety of insect taxa. This review provides an overview of our current understanding of 20E-mediated innate immune responses. The prevalence of correlations between 20E-driven developmental transitions and innate immune activation are summarized across a range of holometabolous insects. Subsequent discussion focuses on studies conducted using the extensive genetic resources available in Drosophila that have begun to reveal the mechanisms underlying 20E regulation of immunity in the contexts of both development and bacterial infection. Lastly, I propose directions for future research into 20E regulation of immunity that will advance our knowledge of how interactive endocrine networks coordinate animals' physiological responses to environmental microbes.
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Affiliation(s)
- Scott A. Keith
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
- Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, United States of America
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7
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Dantzer B. Frank Beach Award Winner: The centrality of the hypothalamic-pituitary-adrenal axis in dealing with environmental change across temporal scales. Horm Behav 2023; 150:105311. [PMID: 36707334 DOI: 10.1016/j.yhbeh.2023.105311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 01/02/2023] [Accepted: 01/06/2023] [Indexed: 01/26/2023]
Abstract
Understanding if and how individuals and populations cope with environmental change is an enduring question in evolutionary ecology that has renewed importance given the pace of change in the Anthropocene. Two evolutionary strategies of coping with environmental change may be particularly important in rapidly changing environments: adaptive phenotypic plasticity and/or bet hedging. Adaptive plasticity could enable individuals to match their phenotypes to the expected environment if there is an accurate cue predicting the selective environment. Diversifying bet hedging involves the production of seemingly random phenotypes in an unpredictable environment, some of which may be adaptive. Here, I review the central role of the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoids (GCs) in enabling vertebrates to cope with environmental change through adaptive plasticity and bet hedging. I first describe how the HPA axis mediates three types of adaptive plasticity to cope with environmental change (evasion, tolerance, recovery) over short timescales (e.g., 1-3 generations) before discussing how the implications of GCs on phenotype integration may depend upon the timescale under consideration. GCs can promote adaptive phenotypic integration, but their effects on phenotypic co-variation could also limit the dimensions of phenotypic space explored by animals over longer timescales. Finally, I discuss how organismal responses to environmental stressors can act as a bet hedging mechanism and therefore enhance evolvability by increasing genetic or phenotypic variability or reducing patterns of genetic and phenotypic co-variance. Together, this emphasizes the crucial role of the HPA axis in understanding fundamental questions in evolutionary ecology.
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Affiliation(s)
- Ben Dantzer
- Department of Psychology, University of Michigan, MI 48109 Ann Arbor, MI, USA; Department of Ecology and Evolutionary Biology, University of Michigan, MI 48109, Ann Arbor, MI, USA.
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8
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Rosvall KA. Evolutionary endocrinology and the problem of Darwin's tangled bank. Horm Behav 2022; 146:105246. [PMID: 36029721 DOI: 10.1016/j.yhbeh.2022.105246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 06/20/2022] [Accepted: 08/10/2022] [Indexed: 11/04/2022]
Abstract
Like Darwin's tangled bank of biodiversity, the endocrine mechanisms that give rise to phenotypic diversity also exhibit nearly endless forms. This tangled bank of mechanistic diversity can prove problematic as we seek general principles on the role of endocrine mechanisms in phenotypic evolution. A key unresolved question is therefore: to what degree are specific endocrine mechanisms re-used to bring about replicated phenotypic evolution? Related areas of inquiry are booming in molecular ecology, but behavioral traits are underrepresented in this literature. Here, I leverage the rich comparative tradition in evolutionary endocrinology to evaluate whether and how certain mechanisms may be repeated hotspots of behavioral evolutionary change. At one extreme, mechanisms may be parallel, such that evolution repeatedly uses the same gene or pathway to arrive at multiple independent (or, convergent) origins of a particular behavioral trait. At the other extreme, the building blocks of behavior may be unique, such that outwardly similar phenotypes are generated via lineage-specific mechanisms. This review synthesizes existing case studies, phylogenetic analyses, and experimental evolutionary research on mechanistic parallelism in animal behavior. These examples show that the endocrine building blocks of behavior have some elements of parallelism across replicated evolutionary events. However, support for parallelism is variable among studies, at least some of which relates to the level of complexity at which we consider sameness (i.e. pathway vs. gene level). Moving forward, we need continued experimentation and better testing of neutral models to understand whether, how - and critically, why - mechanism A is used in one lineage and mechanism B is used in another. We also need continued growth of large-scale comparative analyses, especially those that can evaluate which endocrine parameters are more or less likely to undergo parallel evolution alongside specific behavioral traits. These efforts will ultimately deepen understanding of how and why hormone-mediated behaviors are constructed the way that they are.
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Affiliation(s)
- Kimberly A Rosvall
- Indiana University, Bloomington, USA; Department of Biology, USA; Center for the Integrative Study of Animal Behavior, USA.
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9
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Petrullo L, Delaney D, Boutin S, McAdam AG, Lane JE, Boonstra R, Palme R, Dantzer B. The glucocorticoid response to environmental change is not specific to agents of natural selection in wild red squirrels. Horm Behav 2022; 146:105262. [PMID: 36191397 DOI: 10.1016/j.yhbeh.2022.105262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/30/2022] [Accepted: 09/07/2022] [Indexed: 11/04/2022]
Abstract
Evolutionary endocrinology aims to understand how natural selection shapes endocrine systems and the degree to which endocrine systems themselves can induce phenotypic responses to environmental changes. Such responses may be specialized in that they reflect past selection for responsiveness only to those ecological factors that ultimately influence natural selection. Alternatively, endocrine responses may be broad and generalized, allowing organisms to cope with a variety of environmental changes simultaneously. Here, we empirically tested whether the endocrine response of female North American red squirrels (Tamiasciurus hudsonicus) was specialized or generalized. We first quantified the direction and magnitude of natural selection acting on three female life history traits (parturition date, litter size, offspring postnatal growth rate) during 32 years of fluctuations in four potential ecological agents of selection (food availability, conspecific density, predator abundance, and temperature). Only three of the four variables (food, density, and predators) affected patterns of natural selection on female life history traits. We then quantified fecal glucocorticoid metabolites (FGMs) across 7 years and found that all four environmental variables, regardless of their effects on patterns of selection, were associated with glucocorticoid production. Our results provide support for a generalized, rather than specific, glucocorticoid response to environmental change that can integrate across multiple co-occurring environmental stressors.
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Affiliation(s)
- Lauren Petrullo
- Department of Psychology, University of Michigan, Ann Arbor, MI 48108, USA.
| | - David Delaney
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Andrew G McAdam
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Jeffrey E Lane
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Rudy Boonstra
- Department of Biological Sciences, Centre for the Neurobiology of Stress, University of Toronto Scarborough, Toronto, ON M1C 1A6, Canada
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Veterina ̈rplatz 1, Vienna 1210, Austria
| | - Ben Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI 48108, USA; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48108, USA
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10
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Anderson NK, Goodwin SE, Schuppe ER, Dawn A, Preininger D, Mangiamele LA, Fuxjager MJ. Activational vs. organizational effects of sex steroids and their role in the evolution of reproductive behavior: Looking to foot-flagging frogs and beyond. Horm Behav 2022; 146:105248. [PMID: 36054981 DOI: 10.1016/j.yhbeh.2022.105248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/14/2022] [Accepted: 08/18/2022] [Indexed: 11/21/2022]
Abstract
Sex steroids play an important role in regulation of the vertebrate reproductive phenotype. This is because sex steroids not only activate sexual behaviors that mediate copulation, courtship, and aggression, but they also help guide the development of neural and muscular systems that underlie these traits. Many biologists have therefore described the effects of sex steroid action on reproductive behavior as both "activational" and "organizational," respectively. Here, we focus on these phenomena from an evolutionary standpoint, highlighting that we know relatively little about the way that organizational effects evolve in the natural world to support the adaptation and diversification of reproductive behavior. We first review the evidence that such effects do in fact evolve to mediate the evolution of sexual behavior. We then introduce an emerging animal model - the foot-flagging frog, Staurois parvus - that will be useful to study how sex hormones shape neuromotor development necessary for sexual displays. The foot flag is nothing more than a waving display that males use to compete for access to female mates, and thus the neural circuits that control its production are likely laid down when limb control systems arise during the developmental transition from tadpole to frog. We provide data that highlights how sex steroids might organize foot-flagging behavior through its putative underlying mechanisms. Overall, we anticipate that future studies of foot-flagging frogs will open a powerful window from which to see how sex steroids influence the neuromotor systems to help germinate circuits that drive signaling behavior. In this way, our aim is to bring attention to the important frontier of endocrinological regulation of evolutionary developmental biology (endo-evo-devo) and its relationship to behavior.
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Affiliation(s)
- Nigel K Anderson
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI, United States of America
| | - Sarah E Goodwin
- Department of Biological Sciences, Smith College, Northampton, MA, United States of America
| | - Eric R Schuppe
- Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, CA, United States of America
| | - AllexAndrya Dawn
- Department of Biological Sciences, Smith College, Northampton, MA, United States of America
| | - Doris Preininger
- Department of Evolutionary Biology, University of Vienna, Vienna, Austria; Vienna Zoo, Vienna, Austria
| | - Lisa A Mangiamele
- Department of Biological Sciences, Smith College, Northampton, MA, United States of America.
| | - Matthew J Fuxjager
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI, United States of America.
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11
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Cox CL, Logan ML, Nicholson DJ, Chung AK, Rosso AA, McMillan WO, Cox RM. Species-Specific Expression of Growth-Regulatory Genes in 2 Anoles with Divergent Patterns of Sexual Size Dimorphism. Integr Org Biol 2022; 4:obac025. [PMID: 35958165 PMCID: PMC9362763 DOI: 10.1093/iob/obac025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/20/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
Synopsis
Sexual size dimorphism is widespread in nature and often develops through sexual divergence in growth trajectories. In vertebrates, the growth hormone/insulin-like growth factor (GH/IGF) network is an important regulator of growth, and components of this network are often regulated in sex-specific fashion during the development of sexual size dimorphism. However, expression of the GH/IGF network is not well characterized outside of mammalian model systems, and the extent to which species differences in sexual size dimorphism are related to differences in GH/IGF network expression is unclear. To begin bridging this gap, we compared GH/IGF network expression in liver and muscle from 2 lizard congeners, one with extreme male-biased sexual size dimorphism (brown anole, Anolis sagrei), and one that is sexually monomorphic in size (slender anole, A. apletophallus). Specifically, we tested whether GH/IGF network expression in adult slender anoles resembles the highly sex-biased expression observed in adult brown anoles or the relatively unbiased expression observed in juvenile brown anoles. We found that adults of the 2 species differed significantly in the strength of sex-biased expression for several key upstream genes in the GH/IGF network, including insulin-like growth factors 1 and 2. However, species differences in sex-biased expression were minor when comparing adult slender anoles to juvenile brown anoles. Moreover, the multivariate expression of the entire GH/IGF network (as represented by the first two principal components describing network expression) was sex-biased for the liver and muscle of adult brown anoles, but not for either tissue in juvenile brown anoles or adult slender anoles. Our work suggests that species differences in sex-biased expression of genes in the GH/IGF network (particularly in the liver) may contribute to the evolution of species differences in sexual size dimorphism.
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Affiliation(s)
- Christian L Cox
- Florida International University , 11200 SW 8th St, Miami, FL 33199 , USA
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- Georgia Southern University , 1332 Southern Dr, Statesboro, GA 30458 , USA
| | - Michael L Logan
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- University of Nevada Reno , 1664 N Virginia St, Reno, NV 89557 , USA
| | - Daniel J Nicholson
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- Queen Mary University , Mile End Rd, Bethnal Green, London E1 4NS , UK
- University of Texas-Arlington , 701 S Nedderman Dr. Arlington, TX 76019 , USA
| | - Albert K Chung
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
- Georgia Southern University , 1332 Southern Dr, Statesboro, GA 30458 , USA
- University of Texas-Arlington , 701 S Nedderman Dr. Arlington, TX 76019 , USA
- Princeton University , Princeton, NJ 08544 , USA
| | - Adam A Rosso
- Georgia Southern University , 1332 Southern Dr, Statesboro, GA 30458 , USA
| | - W Owen McMillan
- Smithsonian Tropical Research Institute , Amador Causeway, Panama City , Panama
| | - Robert M Cox
- University of Virginia , Charlottesville, VA 22904 , USA
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12
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Cox RM, Hale MD, Wittman TN, Robinson CD, Cox CL. Evolution of hormone-phenotype couplings and hormone-genome interactions. Horm Behav 2022; 144:105216. [PMID: 35777215 DOI: 10.1016/j.yhbeh.2022.105216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 06/05/2022] [Accepted: 06/20/2022] [Indexed: 12/22/2022]
Abstract
When selection favors a new relationship between a cue and a hormonally mediated response, adaptation can proceed by altering the hormonal signal that is produced or by altering the phenotypic response to the hormonal signal. The field of evolutionary endocrinology has made considerable progress toward understanding the evolution of hormonal signals, but we know much less about the evolution of hormone-phenotype couplings, particularly at the hormone-genome interface. We briefly review and classify the mechanisms through which these hormone-phenotype couplings likely evolve, using androgens and their receptors and genomic response elements to illustrate our view. We then present two empirical studies of hormone-phenotype couplings, one rooted in evolutionary quantitative genetics and another in comparative transcriptomics, each focused on the regulation of sexually dimorphic phenotypes by testosterone (T) in the brown anole lizard (Anolis sagrei). First, we illustrate the potential for hormone-phenotype couplings to evolve by showing that coloration of the dewlap (an ornament used in behavioral displays) exhibits significant heritability in its responsiveness to T, implying that anoles harbor genetic variance in the architecture of hormonal pleiotropy. Second, we combine T manipulations with analyses of the liver transcriptome to ask whether and how statistical methods for characterizing modules of co-expressed genes and in silico techniques for identifying androgen response elements (AREs) can improve our understanding of hormone-genome interactions. We conclude by emphasizing important avenues for future work at the hormone-genome interface, particularly those conducted in a comparative evolutionary framework.
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Affiliation(s)
- Robert M Cox
- Department of Biology, University of Virginia, Charlottesville, VA, USA.
| | - Matthew D Hale
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Tyler N Wittman
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | | | - Christian L Cox
- Department of Biology, University of Virginia, Charlottesville, VA, USA; Biological Sciences, Florida International University, Miami, FL, USA
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13
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McInnis MG, Andreassen OA, Andreazza AC, Alon U, Berk M, Brister T, Burdick KE, Cui D, Frye M, Leboyer M, Mitchell PB, Merikangas K, Nierenberg AA, Nurnberger JI, Pham D, Vieta E, Yatham LN, Young AH. Strategies and foundations for scientific discovery in longitudinal studies of bipolar disorder. Bipolar Disord 2022; 24:499-508. [PMID: 35244317 PMCID: PMC9440950 DOI: 10.1111/bdi.13198] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Bipolar disorder (BD) is a complex and dynamic condition with a typical onset in late adolescence or early adulthood followed by an episodic course with intervening periods of subthreshold symptoms or euthymia. It is complicated by the accumulation of comorbid medical and psychiatric disorders. The etiology of BD remains unknown and no reliable biological markers have yet been identified. This is likely due to lack of comprehensive ontological framework and, most importantly, the fact that most studies have been based on small nonrepresentative clinical samples with cross-sectional designs. We propose to establish large, global longitudinal cohorts of BD studied consistently in a multidimensional and multidisciplinary manner to determine etiology and help improve treatment. Herein we propose collection of a broad range of data that reflect the heterogenic phenotypic manifestations of BD that include dimensional and categorical measures of mood, neurocognitive, personality, behavior, sleep and circadian, life-story, and outcomes domains. In combination with genetic and biological information such an approach promotes the integrating and harmonizing of data within and across current ontology systems while supporting a paradigm shift that will facilitate discovery and become the basis for novel hypotheses.
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Affiliation(s)
| | - Ole A. Andreassen
- NORMENT CentreUniversity of Oslo and Oslo University HospitalOsloNorway
| | - Ana C. Andreazza
- Department of Pharmacology & ToxicologyTemerty Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
| | | | - Michael Berk
- Deakin UniversityIMPACT – the Institute for Mental and Physical Health and Clinical TranslationSchool of MedicineBarwon HealthGeelongAustralia
- OrygenThe National Centre of Excellence in Youth Mental HealthCentre for Youth Mental HealthFlorey Institute for Neuroscience and Mental Health and the Department of PsychiatryThe University of MelbourneMelbourneAustralia
| | - Teri Brister
- National Alliance on Mental IllnessArlingtonVirginiaUSA
| | | | - Donghong Cui
- Shanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghai Mental Health CenterShangaiChina
| | | | - Marion Leboyer
- Département de psychiatrieUniversité Paris Est Creteil (UPEC)AP‐HPHôpitaux Universitaires H. MondorDMU IMPACTINSERM, translational NeuropsychiatryFondation FondaMentalCreteilFrance
| | | | - Kathleen Merikangas
- Intramural Research ProgramNational Institute of Mental HealthBethesdaMarylandUSA
| | | | | | - Daniel Pham
- Milken InstituteCenter for Strategic PhilanthopyWashingtonDistrict of ColumbiaUSA
| | - Eduard Vieta
- Bipolar and Depressive disorders UnitHospital ClinicInstitute of NeuroscienceUniversity of BarcelonaIDIBAPSCIBERSAMBarcelonaCataloniaSpain
| | | | - Allan H. Young
- Department of Psychological MedicineInstitute of Psychiatry, Psychology and NeuroscienceKing’s College London & South London and Maudsley NHS Foundation TrustBethlem Royal HospitalBeckenhamKentUK
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14
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Smirnov AF, Leoke DY, Trukhina AV. Natural and Experimental Sex Reversal in Birds and Other Groups of Vertebrates, with the Exception of Mammals. RUSS J GENET+ 2022. [DOI: 10.1134/s1022795422060114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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15
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Fuxjager MJ, Fusani L, Schlinger BA. Physiological innovation and the evolutionary elaboration of courtship behaviour. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2021.03.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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17
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Anderson NK, Schuppe ER, Gururaja KV, Mangiamele LA, Martinez JCC, Priti H, May RV, Preininger D, Fuxjager MJ. A Common Endocrine Signature Marks the Convergent Evolution of an Elaborate Dance Display in Frogs. Am Nat 2021; 198:522-539. [PMID: 34559606 DOI: 10.1086/716213] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractUnrelated species often evolve similar phenotypic solutions to the same environmental problem, a phenomenon known as convergent evolution. But how do these common traits arise? We address this question from a physiological perspective by assessing how convergence of an elaborate gestural display in frogs (foot-flagging) is linked to changes in the androgenic hormone systems that underlie it. We show that the emergence of this rare display in unrelated anuran taxa is marked by a robust increase in the expression of androgen receptor (AR) messenger RNA in the musculature that actuates leg and foot movements, but we find no evidence of changes in the abundance of AR expression in these frogs' central nervous systems. Meanwhile, the magnitude of the evolutionary change in muscular AR and its association with the origin of foot-flagging differ among clades, suggesting that these variables evolve together in a mosaic fashion. Finally, while gestural displays do differ between species, variation in the complexity of a foot-flagging routine does not predict differences in muscular AR. Altogether, these findings suggest that androgen-muscle interactions provide a conduit for convergence in sexual display behavior, potentially providing a path of least resistance for the evolution of motor performance.
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18
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Lipshutz SE, Rosvall KA. Nesting strategy shapes territorial aggression but not testosterone: A comparative approach in female and male birds. Horm Behav 2021; 133:104995. [PMID: 34000663 DOI: 10.1016/j.yhbeh.2021.104995] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/19/2021] [Accepted: 04/29/2021] [Indexed: 11/21/2022]
Abstract
Our understanding of the proximate and ultimate mechanisms shaping competitive reproductive phenotypes primarily stems from research on male-male competition for mates, even though competition is widespread in both sexes. We evaluate the hypothesis that the restricted nature of a resource required for reproduction, i.e. nest site, is a key variable driving territorial competition and testosterone secretion in female and male birds. Obligate secondary cavity-nesting has evolved repeatedly across avian lineages, providing a useful comparative context to explore how competition over limited nest cavities shapes aggression and its underlying mechanisms across species. Although evidence from one or another cavity-nesting species suggests that territorial aggression is adaptive in both females and males, this has not yet been tested in a comparative framework. We predicted that cavity-nesting generates more robust territorial aggression, in comparison to close relatives with less restrictive nesting strategies. Our focal species were two obligate secondary cavity-nesting species and two related species with more flexible nesting strategies in the same avian family: tree swallow (Tachycineta bicolor) vs. barn swallow (Hirundo rustica); Eastern bluebird (Sialia sialis) vs. American robin (Turdus migratorius). We assayed conspecific aggression using simulated territorial intrusion and found that cavity-nesting species displayed greater territorial aggression than their close relatives. This pattern held for both females and males. Because territorial aggression is often associated with elevated testosterone, we also hypothesized that cavity-nesting species would exhibit higher testosterone levels in circulation. However, cavity-nesting species did not have higher testosterone in circulation for either sex, despite some correlative evidence that testosterone is associated with higher rates of physical attack in female tree swallows. Our focus on a context that is relevant to both sexes - competition over essential breeding resources - provides a useful framework for co-consideration of proximate and ultimate drivers of reproductive competition in females and males.
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Affiliation(s)
- Sara E Lipshutz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
| | - Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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19
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Wittman TN, Robinson CD, McGlothlin JW, Cox RM. Hormonal pleiotropy structures genetic covariance. Evol Lett 2021; 5:397-407. [PMID: 34367664 PMCID: PMC8327939 DOI: 10.1002/evl3.240] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 05/03/2021] [Accepted: 05/17/2021] [Indexed: 11/08/2022] Open
Abstract
Quantitative genetic theory proposes that phenotypic evolution is shaped by G, the matrix of genetic variances and covariances among traits. In species with separate sexes, the evolution of sexual dimorphism is also shaped by B, the matrix of between‐sex genetic variances and covariances. Despite considerable focus on estimating these matrices, their underlying biological mechanisms are largely speculative. We experimentally tested the hypothesis that G and B are structured by hormonal pleiotropy, which occurs when one hormone influences multiple phenotypes. Using juvenile brown anole lizards (Anolis sagrei) bred in a paternal half‐sibling design, we elevated the steroid hormone testosterone with slow‐release implants while administering empty implants to siblings as a control. We quantified the effects of this manipulation on the genetic architecture of a suite of sexually dimorphic traits, including body size (males are larger than females) and the area, hue, saturation, and brightness of the dewlap (a colorful ornament that is larger in males than in females). Testosterone masculinized females by increasing body size and dewlap area, hue, and saturation, while reducing dewlap brightness. Control females and males differed significantly in G, but treatment of females with testosterone rendered G statistically indistinguishable from males. Whereas B was characterized by low between‐sex genetic correlations when estimated between control females and males, these same correlations increased significantly when estimated between testosterone females and either control or testosterone males. The full G matrix (including B) for testosterone females and either control or testosterone males was significantly less permissive of sexually dimorphic evolution than was G estimated between control females and males, suggesting that natural sex differences in testosterone help decouple genetic variance between the sexes. Our results confirm that hormonal pleiotropy structures genetic covariance, implying that hormones play an important yet overlooked role in mediating evolutionary responses to selection.
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Affiliation(s)
- Tyler N Wittman
- Department of Biology University of Virginia Charlottesville Virginia 22904
| | | | - Joel W McGlothlin
- Department of Biological Sciences Virginia Tech Blacksburg Virginia 24061
| | - Robert M Cox
- Department of Biology University of Virginia Charlottesville Virginia 22904
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20
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Loveland JL, Lank DB, Küpper C. Gene Expression Modification by an Autosomal Inversion Associated With Three Male Mating Morphs. Front Genet 2021; 12:641620. [PMID: 34149796 PMCID: PMC8213371 DOI: 10.3389/fgene.2021.641620] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/22/2021] [Indexed: 11/22/2022] Open
Abstract
Chromosomal inversions are structural rearrangements that frequently provide genomic substrate for phenotypic diversity. In the ruff Philomachus pugnax, three distinct male reproductive morphs (Independents, Satellites and Faeders) are genetically determined by a 4.5 Mb autosomal inversion. Here we test how this stable inversion polymorphism affects gene expression in males during the lekking season. Gene expression may be altered through disruptions at the breakpoints and the accumulation of mutations due to suppressed recombination. We used quantitative PCR to measure expression of 11 candidate inversion genes across three different tissues (liver, adrenal glands and gonads) and tested for allelic imbalance in four inversion genes across 12 males of all three morphs (8 Independents, 2 Satellites, 2 Faeders). We quantified transcripts of CENPN, an essential gene disrupted by the inversion at the proximal breakpoint, at different exons distributed near and across the breakpoint region. Consistent with dosage dependent gene expression for the breakpoint gene CENPN, we found that expression in Independents was broadly similar for transcripts segments from inside and outside the inversion regions, whereas for Satellites and Faeders, transcript segments outside of the inversion showed at least twofold higher expression than those spanning over the breakpoint. Within the inversion, observed expression differences for inversion males across all four genes with allele-specific primers were consistent with allelic imbalance. We further analyzed gonadal expression of two inversion genes, HSD17B2 and SDR42E1, along with 12 non-inversion genes related to steroid metabolism and signaling in 25 males (13 Independents, 7 Satellites, 5 Faeders). Although we did not find clear morph differentiation for many individual genes, all three morphs could be separated based on gene expression differences when using linear discriminant analysis (LDA), regardless of genomic location (i.e., inside or outside of the inversion). This was robust to the removal of genes with the highest loadings. Pairwise correlations in the expression of genes showed significant correlations for 9–18 pairs of genes within morphs. However, between morphs, we only found a single association between genes SDR42E1 and AROM for Independents and Satellites. Our results suggest complex and wide-ranging changes in gene expression caused by structural variants.
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Affiliation(s)
- Jasmine L Loveland
- Research Group for Behavioural Genetics and Evolutionary Ecology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - David B Lank
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Clemens Küpper
- Research Group for Behavioural Genetics and Evolutionary Ecology, Max Planck Institute for Ornithology, Seewiesen, Germany
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21
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Chung MHJ, Jennions MD, Fox RJ. Quantifying the costs of pre- and postcopulatory traits for males: Evidence that costs of ejaculation are minor relative to mating effort. Evol Lett 2021; 5:315-327. [PMID: 34367658 PMCID: PMC8327938 DOI: 10.1002/evl3.228] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/08/2021] [Accepted: 04/12/2021] [Indexed: 12/12/2022] Open
Abstract
Although it is widely stated that both mating behavior and sperm traits are energetically costly for males, we currently lack empirical estimates of the relative costs to males of pre‐ versus postcopulatory investments. Such estimates require the experimental separation of the act of mating from that of ejaculation, which is a nontrivial logistical challenge. Here, we overcome this challenge using a novel morphological manipulation (gonopodium tip ablation) in the eastern mosquitofish (Gambusia holbrooki) to tease apart investment in mating effort from that in sperm replenishment following ejaculation. We quantified the relative cumulative costs of investing in mating effort and ejaculation by comparing somatic traits and reproductive performance among three types of males: ablated males that could attempt to mate but not ejaculate; unablated males that could both mate and ejaculate; and control males that had no access to females. We show that, after eight weeks, mating investment significantly reduces both body growth and immunocompetence and results in a significant decline in mating effort. In contrast, cumulative investment into sperm replenishment following ejaculation has few detectable effects that are only apparent in smaller males. These minor costs occur despite the fact that G. holbrooki has very high levels of sperm competition and multiple mating by both sexes, which is usually associated with elevated levels of sperm production. Crucially, our study is the first, to our knowledge, to experimentally compare the relative costs of pre‐ and postcopulatory investment on components of male fitness in a vertebrate.
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Affiliation(s)
- Meng-Han Joseph Chung
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT 2601 Australia
| | - Michael D Jennions
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT 2601 Australia
| | - Rebecca J Fox
- Division of Ecology and Evolution Research School of Biology Australian National University Canberra ACT 2601 Australia
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22
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Curlis JD, Cox CL, Cox RM. Sex-Specific Population Differences in Resting Metabolism Are Associated with Intraspecific Variation in Sexual Size Dimorphism of Brown Anoles. Physiol Biochem Zool 2021; 94:205-214. [PMID: 33970831 DOI: 10.1086/714638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractSexual size dimorphism can vary in direction and magnitude across populations, but the extent to which such intraspecific variation is associated with sex and population differences in underlying metabolic processes is unclear. We compared resting metabolic rates (RMRs) of brown anole lizards (Anolis sagrei) from two island populations in the Bahamas (Eleuthera and Great Exuma) that differ in the magnitude of male-biased sexual size dimorphism. Whereas females from each population exhibit similar growth rates and body sizes, males from Great Exuma grow more quickly and attain larger body sizes than males from Eleuthera. We found that these population differences in growth of males persisted in captivity. Therefore, we predicted that males from each population would differ in RMR, whereas females would not. Consistent with this prediction, we found that RMR of males from Eleuthera was higher than that of males from Great Exuma, particularly at higher temperatures. As predicted, RMR of females did not differ between populations. Despite this apparent sex-specific trade-off between growth rate and RMR at the population level, we found a positive relationship between growth rate and RMR at the individual level. The fact that Great Exuma males maintain lower RMR than Eleuthera males, despite their greater absolute growth rates and the positive relationship between RMR and growth rate across individuals, suggests that Great Exuma males may have lower baseline metabolic demands and/or greater growth efficiency than Eleuthera males. Our results call attention to sex-specific divergence in metabolism as a potential mechanism for intraspecific divergence in sexual size dimorphism.
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23
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Robinson CD, Lance SL, Gifford ME. Reproductive success, apparent survival, and ventral blue coloration in male prairie lizards (
Sceloporus consobrinus
). J Zool (1987) 2021. [DOI: 10.1111/jzo.12890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- C. D. Robinson
- University of Virginia Charlottesville VA USA
- University of Central Arkansas Conway AR USA
| | - S. L. Lance
- Savannah River Ecology Laboratory University of Georgia Aiken SC USA
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24
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Huang A, Kandhi S, Sun D. Roles of Genetic Predisposition in the Sex Bias of Pulmonary Pathophysiology, as a Function of Estrogens : Sex Matters in the Prevalence of Lung Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1303:107-127. [PMID: 33788190 DOI: 10.1007/978-3-030-63046-1_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In addition to studies focused on estrogen mediation of sex-different regulation of systemic circulations, there is now increasing clinical relevance and research interests in the pulmonary circulation, in terms of sex differences in the morbidity and mortality of lung diseases such as inherent-, allergic- and inflammatory-based events. Thus, female predisposition to pulmonary artery hypertension (PAH) is an inevitable topic. To better understand the nature of sexual differentiation in the pulmonary circulation, and how heritable factors, in vivo- and/or in vitro-altered estrogen circumstances and changes in the live environment work in concert to discern the sex bias, this chapter reviews pulmonary events characterized by sex-different features, concomitant with exploration of how alterations of genetic expression and estrogen metabolisms trigger the female-predominant pathological signaling. We address the following: PAH (Sect.7.2) is characterized as an estrogenic promotion of its incidence (Sect. 7.2.2), as a function of specific germline mutations, and as an estrogen-elicited protection of its prognosis (Sect.7.2.1). More detail is provided to introduce a less recognized gene of Ephx2 that encodes soluble epoxide hydrolase (sEH) to degrade epoxyeicosatrienic acids (EETs). As a susceptible target of estrogen, Ephx2/sEH expression is downregulated by an estrogen-dependent epigenetic mechanism. Increases in pulmonary EETs then evoke a potentiation of PAH generation, but mitigation of its progression, a phenomenon similar to the estrogen-paradox regulation of PAH. Additionally, the female susceptibility to chronic obstructive pulmonary diseases (Sect. 7.3) and asthma (Sect.7.4), but less preference to COVID-19 (Sect. 7.5), and roles of estrogen in their pathogeneses are briefly discussed.
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Affiliation(s)
- An Huang
- Department of Physiology, New York Medical College, Valhalla, NY, USA.
| | - Sharath Kandhi
- Department of Physiology, New York Medical College, Valhalla, NY, USA
| | - Dong Sun
- Department of Physiology, New York Medical College, Valhalla, NY, USA
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25
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Duncan CA, Cohick WS, John-Alder HB. Testosterone Reduces Growth and Hepatic IGF-1 mRNA in a Female-Larger Lizard, Sceloporus undulatus: Evidence of an Evolutionary Reversal in Growth Regulation. Integr Org Biol 2021; 2:obaa036. [PMID: 33791574 PMCID: PMC7715992 DOI: 10.1093/iob/obaa036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Previous research has demonstrated that testosterone (T) can inhibit growth in female-larger species and stimulate growth in male-larger species, but the underlying mechanisms of this regulatory bipotentiality have not been investigated. In this study, we investigated the effects of T on the expression of hepatic insulin-like growth factor-1 (IGF-1) mRNA and circulating IGF-1 hormone in Sceloporus undulatus, a species of lizard in which females grow faster to become larger than males and in which T inhibits growth. Experiments were performed in captivity on mature female and male adults in the asymptotic phase of their growth curve and on actively growing, pre-reproductive juveniles. In adult males, the expression of hepatic IGF-1 mRNA increased following surgical castration and returned to control levels with T replacement; in intact adult females, exogenous T had no effect on IGF-1 mRNA expression. In juveniles, T significantly reduced both growth and the expression of hepatic IGF-1 mRNA to similar extents in intact females and in castrated males. The relative inhibitory effects of T on mRNA expression were greater in juveniles than in adults. Plasma IGF-1 hormone was about four times higher in juveniles than in adults, but T had no significant effect on IGF-1 hormone in either sex or in either age group. Our finding of inhibition of the expression of hepatic IGF-1 mRNA stands in contrast to the stimulatory effects of T in the published body of literature. We attribute our novel finding to our use of a species in which T inhibits rather than stimulates growth. Our findings begin to explain how T has the regulatory bipotentiality to be stimulatory in some species and inhibitory in others, requiring only an evolutionary reversal in the molecular regulation of growth-regulatory genes including IGF-1. Further comparative transcriptomic studies will be required to fully resolve the molecular mechanism of growth inhibition.
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Affiliation(s)
| | - Wendie S Cohick
- Graduate Program in Endocrinology and Animal Biosciences, Rutgers University, 84 Lipman Drive, New Brunswick, NJ 08901, USA
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26
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Affiliation(s)
- Sean C Lema
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA, 93407, USA.
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27
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Abstract
Synopsis
Females of some species are considered sex-role reversed, meaning that they face stronger competition for mates compared to males. While much attention has been paid to behavioral and morphological patterns associated with sex-role reversal, less is known about its physiological regulation. Here, we evaluate hypotheses relating to the neuroendocrine basis of sex-role reversal. We refute the most widely tested activational hypothesis for sex differences in androgen secretion; sex-role reversed females do not have higher levels of androgens in circulation than males. However, we find some evidence that the effects of androgens may be sex-specific; circulating androgen levels correlate with some competitive phenotypes in sex-role reversed females. We also review evidence that sex-role reversed females have higher tissue-specific sensitivity to androgens than males, at least in some species and tissues. Organizational effects may explain these relationships, considering that early exposure to sex steroids can shape later sensitivity to hormones, often in sex-specific ways. Moving forward, experimental and correlative studies on the ontogeny and expression of sex-role reversal will further clarify the mechanisms that generate sex-specific behaviors and sex roles.
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Affiliation(s)
- Sara E Lipshutz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
- Center for the Integrated Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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