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Freiler MK, Deckard ML, Proffitt MR, Troy Smith G. Differential expression of steroid-related genes across electrosensory brain regions in two sexually dimorphic species of electric knifefish. Gen Comp Endocrinol 2024; 355:114549. [PMID: 38797340 DOI: 10.1016/j.ygcen.2024.114549] [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: 12/30/2023] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/29/2024]
Abstract
The production of communication signals can be modulated by hormones acting on the brain regions that regulate these signals. However, less is known about how signal perception is regulated by hormones. The electrocommunication signals of weakly electric fishes are sexually dimorphic, sensitive to hormones, and vary across species. The neural circuits that regulate the production and perception of these signals are also well-characterized, and electric fishes are thus an excellent model to examine the neuroendocrine regulation of sensorimotor mechanisms of communication. We investigated (1) whether steroid-related genes are expressed in sensory brain regions that process communication signals; and (2) whether this expression differs across sexes and species that have different patterns of sexual dimorphism in their signals. Apteronotus leptorhynchus and Apteronotus albifrons produce continuous electric organ discharges (EODs) that are used for communication. Two brain regions, the electrosensory lateral line lobe (ELL) and the dorsal torus semicircularis (TSd), process inputs from electroreceptors to allow fish to detect and discriminate electrocommunication signals. We used qPCR to quantify the expression of genes for two androgen receptors (ar1, ar2), two estrogen receptors (esr1, esr2b), and aromatase (cyp19a1b). Four out of five steroid-related genes were expressed in both sensory brain regions, and their expression often varied between sexes and species. These results suggest that expression of steroid-related genes in the brain may differentially influence how EOD signals are encoded across species and sexes, and that gonadal steroids may coordinately regulate central circuits that control both the production and perception of EODs.
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Affiliation(s)
- Megan K Freiler
- Department of Biology, Indiana University, 1001 E 3(rd) St., Bloomington, IN 47405, United States; Center for the Integrative Study of Animal Behavior, Indiana University, 409 N. Park Ave, Bloomington, IN 47405, United States.
| | - Mikayla L Deckard
- Department of Biology, Indiana University, 1001 E 3(rd) St., Bloomington, IN 47405, United States
| | - Melissa R Proffitt
- Department of Biology, Indiana University, 1001 E 3(rd) St., Bloomington, IN 47405, United States; Center for the Integrative Study of Animal Behavior, Indiana University, 409 N. Park Ave, Bloomington, IN 47405, United States
| | - G Troy Smith
- Department of Biology, Indiana University, 1001 E 3(rd) St., Bloomington, IN 47405, United States; Center for the Integrative Study of Animal Behavior, Indiana University, 409 N. Park Ave, Bloomington, IN 47405, United States
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2
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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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3
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López-Murillo C, Hinestroza-Morales S, Henny P, Toledo J, Cardona-Gómez GP, Rivera-Gutiérrez H, Posada-Duque R. Differences in vocal brain areas and astrocytes between the house wren and the rufous-tailed hummingbird. Front Neuroanat 2024; 18:1339308. [PMID: 38601797 PMCID: PMC11004282 DOI: 10.3389/fnana.2024.1339308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/06/2024] [Indexed: 04/12/2024] Open
Abstract
The house wren shows complex song, and the rufous-tailed hummingbird has a simple song. The location of vocal brain areas supports the song's complexity; however, these still need to be studied. The astrocytic population in songbirds appears to be associated with change in vocal control nuclei; however, astrocytic distribution and morphology have not been described in these species. Consequently, we compared the distribution and volume of the vocal brain areas: HVC, RA, Area X, and LMAN, cell density, and the morphology of astrocytes in the house wren and the rufous-tailed hummingbird. Individuals of the two species were collected, and their brains were analyzed using serial Nissl- NeuN- and MAP2-stained tissue scanner imaging, followed by 3D reconstructions of the vocal areas; and GFAP and S100β astrocytes were analyzed in both species. We found that vocal areas were located close to the cerebral midline in the house wren and a more lateralized position in the rufous-tailed hummingbird. The LMAN occupied a larger volume in the rufous-tailed hummingbird, while the RA and HVC were larger in the house wren. While Area X showed higher cell density in the house wren than the rufous-tailed hummingbird, the LMAN showed a higher density in the rufous-tailed hummingbird. In the house wren, GFAP astrocytes in the same bregma where the vocal areas were located were observed at the laminar edge of the pallium (LEP) and in the vascular region, as well as in vocal motor relay regions in the pallidum and mesencephalon. In contrast, GFAP astrocytes were found in LEP, but not in the pallidum and mesencephalon in hummingbirds. Finally, when comparing GFAP astrocytes in the LEP region of both species, house wren astrocytes exhibited significantly more complex morphology than those of the rufous-tailed hummingbird. These findings suggest a difference in the location and cellular density of vocal circuits, as well as morphology of GFAP astrocytes between the house wren and the rufous-tailed hummingbird.
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Affiliation(s)
- Carolina López-Murillo
- Área de Neurofisiología Celular, Grupo de Neurociencias de Antioquia, Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellin, Colombia
| | - Santiago Hinestroza-Morales
- Área de Neurofisiología Celular, Grupo de Neurociencias de Antioquia, Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellin, Colombia
| | - Pablo Henny
- Laboratorio de Neuroanatomía, Departamento de Anatomía, and Centro Interdisciplinario de Neurociencia, NeuroUC, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jorge Toledo
- Scientific Equipment Network REDECA, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Gloria Patricia Cardona-Gómez
- Área de Neurobiología Celular y Molecular, Grupo de Neurociencias de Antioquia, Facultad de Medicina, Sede de Investigaciones Universitarias, Universidad de Antioquia, Medellin, Colombia
| | - Héctor Rivera-Gutiérrez
- Grupo de Investigación de Ecología y Evolución de Vertebrados, Instituto de Biología, Universidad de Antioquia, Medellin, Colombia
| | - Rafael Posada-Duque
- Área de Neurofisiología Celular, Grupo de Neurociencias de Antioquia, Instituto de Biología, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Medellin, Colombia
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4
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Roggenbuck EC, Hall EA, Hanson IB, Roby AA, Zhang KK, Alkatib KA, Carter JA, Clewner JE, Gelfius AL, Gong S, Gordon FR, Iseler JN, Kotapati S, Li M, Maysun A, McCormick EO, Rastogi G, Sengupta S, Uzoma CU, Wolkov MA, Clowney EJ. Let's talk about sex: Mechanisms of neural sexual differentiation in Bilateria. WIREs Mech Dis 2024; 16:e1636. [PMID: 38185860 DOI: 10.1002/wsbm.1636] [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: 05/09/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 01/09/2024]
Abstract
In multicellular organisms, sexed gonads have evolved that facilitate release of sperm versus eggs, and bilaterian animals purposefully combine their gametes via mating behaviors. Distinct neural circuits have evolved that control these physically different mating events for animals producing eggs from ovaries versus sperm from testis. In this review, we will describe the developmental mechanisms that sexually differentiate neural circuits across three major clades of bilaterian animals-Ecdysozoa, Deuterosomia, and Lophotrochozoa. While many of the mechanisms inducing somatic and neuronal sex differentiation across these diverse organisms are clade-specific rather than evolutionarily conserved, we develop a common framework for considering the developmental logic of these events and the types of neuronal differences that produce sex-differentiated behaviors. This article is categorized under: Congenital Diseases > Stem Cells and Development Neurological Diseases > Stem Cells and Development.
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Affiliation(s)
- Emma C Roggenbuck
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Elijah A Hall
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Isabel B Hanson
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Alyssa A Roby
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine K Zhang
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Kyle A Alkatib
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Joseph A Carter
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jarred E Clewner
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Anna L Gelfius
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Shiyuan Gong
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Finley R Gordon
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jolene N Iseler
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Samhita Kotapati
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Marilyn Li
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Areeba Maysun
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Elise O McCormick
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Geetanjali Rastogi
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Srijani Sengupta
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Chantal U Uzoma
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Madison A Wolkov
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - E Josephine Clowney
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
- Michigan Neuroscience Institute Affiliate, University of Michigan, Ann Arbor, Michigan, USA
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5
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Kelley DB. Convergent and divergent neural circuit architectures that support acoustic communication. Front Neural Circuits 2022; 16:976789. [PMID: 36466364 PMCID: PMC9712726 DOI: 10.3389/fncir.2022.976789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 10/19/2022] [Indexed: 11/18/2022] Open
Abstract
Vocal communication is used across extant vertebrates, is evolutionarily ancient, and been maintained, in many lineages. Here I review the neural circuit architectures that support intraspecific acoustic signaling in representative anuran, mammalian and avian species as well as two invertebrates, fruit flies and Hawaiian crickets. I focus on hindbrain motor control motifs and their ties to respiratory circuits, expression of receptors for gonadal steroids in motor, sensory, and limbic neurons as well as divergent modalities that evoke vocal responses. Hindbrain and limbic participants in acoustic communication are highly conserved, while forebrain participants have diverged between anurans and mammals, as well as songbirds and rodents. I discuss the roles of natural and sexual selection in driving speciation, as well as exaptation of circuit elements with ancestral roles in respiration, for producing sounds and driving rhythmic vocal features. Recent technical advances in whole brain fMRI across species will enable real time imaging of acoustic signaling partners, tying auditory perception to vocal production.
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6
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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: 5] [Impact Index Per Article: 2.5] [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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7
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Smiley KO, Lipshutz SE, Kimmitt AA, DeVries MS, Cain KE, George EM, Covino KM. Beyond a biased binary: A perspective on the misconceptions, challenges, and implications of studying females in avian behavioral endocrinology. Front Physiol 2022; 13:970603. [PMID: 36213250 PMCID: PMC9532843 DOI: 10.3389/fphys.2022.970603] [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: 06/16/2022] [Accepted: 08/18/2022] [Indexed: 12/04/2022] Open
Abstract
For decades, avian endocrinology has been informed by male perspectives and male-focused research, leaving significant gaps in our understanding of female birds. Male birds have been favored as research subjects because their reproductive behaviors are considered more conspicuous and their reproductive physiology is presumably less complex than female birds. However, female birds should not be ignored, as female reproductive behavior and physiology are essential for the propagation of all avian species. Endocrine research in female birds has made much progress in the last 20 years, but a substantial disparity in knowledge between male and female endocrinology persists. In this perspective piece, we provide examples of why ornithology has neglected female endocrinology, and we propose considerations for field and laboratory techniques to facilitate future studies. We highlight recent advances that showcase the importance of female avian endocrinology, and we challenge historic applications of an oversimplified, male-biased lens. We further provide examples of species for which avian behavior differs from the stereotypically described behaviors of male and female birds, warning investigators of the pitfalls in approaching endocrinology with a binary bias. We hope this piece will inspire investigators to engage in more comprehensive studies with female birds, to close the knowledge gap between the sexes, and to look beyond the binary when drawing conclusions about what is ‘male’ versus ‘female’ biology.
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Affiliation(s)
- Kristina O. Smiley
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Center for Neuroendocrine Studies and Department of Psychological and Brain Sciences, University of Massachusetts-Amherst, Amherst, MA, United States
- *Correspondence: Kristina O. Smiley,
| | - Sara E. Lipshutz
- Biology Department, Loyola University Chicago, Chicago, IL, United States
| | - Abigail A. Kimmitt
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, United States
| | - M. Susan DeVries
- Department of Biological Sciences, University of Wisconsin-Whitewater, Whitewater, WI, United States
| | - Kristal E. Cain
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Elizabeth M. George
- Biology Department, Texas A&M University, College Station, TX, United States
| | - Kristen. M. Covino
- Biology Department, Loyola Marymount University, Los Angeles, CA, United States
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8
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Androgen receptor α peak expression in retina rather than gonad of Hainan medaka, Oryzias curvinotus. REPRODUCTION AND BREEDING 2022. [DOI: 10.1016/j.repbre.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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9
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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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Goymann W, Schwabl H. The tyranny of phylogeny-A plea for a less dogmatic stance on two-species comparisons: Funding bodies, journals and referees discourage two- or few-species comparisons, but such studies provide essential insights complementary to phylogenetic comparative studies. Bioessays 2021; 43:e2100071. [PMID: 34155665 DOI: 10.1002/bies.202100071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 11/11/2022]
Abstract
Phylogenetically controlled studies across multiple species correct for taxonomic confounds in physiological performance traits. Therefore, they are preferred over comparisons of two or few closely-related species. Funding bodies, referees and journal editors nowadays often even reject to consider detailed comparisons of two or few closely related species. Here, we plea for a less dogmatic stance on such comparisons, because phylogenetic studies come with their own limitations similar in magnitude as those of two-species comparisons. Two-species comparisons are particularly relevant and instructive for understanding physiological pathways and de novo mutations in three contexts: in a purely mechanistic context, when differences in the regulation of a trait are the focus of investigation, when a physiological trait lacks a direct connection to fitness, and when physiological measures cannot easily be standardized among laboratories. In conclusion, phylogenetic comparative and two-species studies have different strengths and weaknesses and combining these complementary approaches will help integrating biology.
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Affiliation(s)
- Wolfgang Goymann
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Hubert Schwabl
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
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11
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Taubenheim J, Kortmann C, Fraune S. Function and Evolution of Nuclear Receptors in Environmental-Dependent Postembryonic Development. Front Cell Dev Biol 2021; 9:653792. [PMID: 34178983 PMCID: PMC8222990 DOI: 10.3389/fcell.2021.653792] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/06/2021] [Indexed: 12/14/2022] Open
Abstract
Nuclear receptors (NRs) fulfill key roles in the coordination of postembryonal developmental transitions in animal species. They control the metamorphosis and sexual maturation in virtually all animals and by that the two main environmental-dependent developmental decision points. Sexual maturation and metamorphosis are controlled by steroid receptors and thyroid receptors, respectively in vertebrates, while both processes are orchestrated by the ecdysone receptor (EcR) in insects. The regulation of these processes depends on environmental factors like nutrition, temperature, or photoperiods and by that NRs form evolutionary conserved mediators of phenotypic plasticity. While the mechanism of action for metamorphosis and sexual maturation are well studied in model organisms, the evolution of these systems is not entirely understood and requires further investigation. We here review the current knowledge of NR involvement in metamorphosis and sexual maturation across the animal tree of life with special attention to environmental integration and evolution of the signaling mechanism. Furthermore, we compare commonalities and differences of the different signaling systems. Finally, we identify key gaps in our knowledge of NR evolution, which, if sufficiently investigated, would lead to an importantly improved understanding of the evolution of complex signaling systems, the evolution of life history decision points, and, ultimately, speciation events in the metazoan kingdom.
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Affiliation(s)
- Jan Taubenheim
- Zoology and Organismic Interactions, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Constantin Kortmann
- Zoology and Organismic Interactions, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sebastian Fraune
- Zoology and Organismic Interactions, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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12
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Choe HN, Jarvis ED. The role of sex chromosomes and sex hormones in vocal learning systems. Horm Behav 2021; 132:104978. [PMID: 33895570 DOI: 10.1016/j.yhbeh.2021.104978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/22/2021] [Accepted: 03/23/2021] [Indexed: 12/12/2022]
Abstract
Vocal learning is the ability to imitate and modify sounds through auditory experience, a rare trait found in only a few lineages of mammals and birds. It is a critical component of human spoken language, allowing us to verbally transmit speech repertoires and knowledge across generations. In many vocal learning species, the vocal learning trait is sexually dimorphic, where it is either limited to males or present in both sexes to different degrees. In humans, recent findings have revealed subtle sexual dimorphism in vocal learning/spoken language brain regions and some associated disorders. For songbirds, where the neural mechanisms of vocal learning have been well studied, vocal learning appears to have been present in both sexes at the origin of the lineage and was then independently lost in females of some subsequent lineages. This loss is associated with an interplay between sex chromosomes and sex steroid hormones. Even in species with little dimorphism, like humans, sex chromosomes and hormones still have some influence on learned vocalizations. Here we present a brief synthesis of these studies, in the context of sex determination broadly, and identify areas of needed investigation to further understand how sex chromosomes and sex steroid hormones help establish sexually dimorphic neural structures for vocal learning.
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Affiliation(s)
- Ha Na Choe
- Duke University Medical Center, The Rockefeller University, Howard Hughes Medical Institute, United States of America.
| | - Erich D Jarvis
- Duke University Medical Center, The Rockefeller University, Howard Hughes Medical Institute, United States of America.
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Ko MC, Frankl-Vilches C, Bakker A, Gahr M. The Gene Expression Profile of the Song Control Nucleus HVC Shows Sex Specificity, Hormone Responsiveness, and Species Specificity Among Songbirds. Front Neurosci 2021; 15:680530. [PMID: 34135731 PMCID: PMC8200640 DOI: 10.3389/fnins.2021.680530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
Singing occurs in songbirds of both sexes, but some species show typical degrees of sex-specific performance. We studied the transcriptional sex differences in the HVC, a brain nucleus critical for song pattern generation, of the forest weaver (Ploceus bicolor), the blue-capped cordon-bleu (Uraeginthus cyanocephalus), and the canary (Serinus canaria), which are species that show low, medium, and high levels of sex-specific singing, respectively. We observed persistent sex differences in gene expression levels regardless of the species-specific sexual singing phenotypes. We further studied the HVC transcriptomes of defined phenotypes of canary, known for its testosterone-sensitive seasonal singing. By studying both sexes of canaries during both breeding and non-breeding seasons, non-breeding canaries treated with testosterone, and spontaneously singing females, we found that the circulating androgen levels and sex were the predominant variables associated with the variations in the HVC transcriptomes. The comparison of natural singing with testosterone-induced singing in canaries of the same sex revealed considerable differences in the HVC transcriptomes. Strong transcriptional changes in the HVC were detected during the transition from non-singing to singing in canaries of both sexes. Although the sex-specific genes of singing females shared little resemblance with those of males, our analysis showed potential functional convergences. Thus, male and female songbirds achieve comparable singing behaviours with sex-specific transcriptomes.
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Affiliation(s)
- Meng-Ching Ko
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Carolina Frankl-Vilches
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Antje Bakker
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
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Villavicencio CP, Windley H, D'Amelio PB, Gahr M, Goymann W, Quispe R. Neuroendocrine patterns underlying seasonal song and year-round territoriality in male black redstarts. Front Zool 2021; 18:8. [PMID: 33627161 PMCID: PMC7905601 DOI: 10.1186/s12983-021-00389-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 02/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The connection between testosterone and territoriality in free-living songbirds has been well studied in a reproductive context, but less so outside the breeding season. To assess the effects of seasonal androgenic action on territorial behavior, we analyzed vocal and non-vocal territorial behavior in response to simulated territorial intrusions (STIs) during three life-cycle stages in free-living male black redstarts: breeding, molt and nonbreeding. Concurrently, we measured changes in circulating testosterone levels, as well as the mRNA expression of androgen and estrogen receptors and aromatase in the preoptic, hypothalamic and song control brain areas that are associated with social and vocal behaviors. RESULTS Territorial behavior and estrogen receptor expression in hypothalamic areas did not differ between stages. But plasma testosterone was higher during breeding than during the other stages, similar to androgen receptor and aromatase expression in the preoptic area. The expression of androgen receptors in the song control nucleus HVC was lower during molt when birds do not sing or sing rarely, but similar between the breeding and the nonbreeding stage. Nevertheless, some song spectral features and the song repertoire differed between breeding and nonbreeding. Territorial behavior and song rate correlated with the expression of steroid receptors in hypothalamic areas, and in the song control nucleus lMAN. CONCLUSIONS Our results demonstrate seasonal modulation of song, circulating testosterone levels, and brain sensitivity to androgens, but a year-round persistency of territorial behavior and estrogen receptor expression in all life-cycle stages. This suggests that seasonal variations in circulating testosterone concentrations and brain sensitivity to androgens is widely uncoupled from territorial behavior and song activity but might still affect song pattern. Our study contributes to the understanding of the complex comparative neuroendocrinology of song birds in the wild.
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Affiliation(s)
- Camila P Villavicencio
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany. .,Department of Ecological Science, Institute of Ecology and Biodiversity, Faculty of Science, University of Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.
| | - Harriet Windley
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany
| | - Pietro B D'Amelio
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany.,FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch, 7701, South Africa
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany
| | - Wolfgang Goymann
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany
| | - René Quispe
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany.,Department of Marine Biology, Faculty of Ocean Sciences, Universidad Catolica del Norte (UCN), Larrondo 1281, Coquimbo, Chile
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Cox RM. Sex steroids as mediators of phenotypic integration, genetic correlations, and evolutionary transitions. Mol Cell Endocrinol 2020; 502:110668. [PMID: 31821857 DOI: 10.1016/j.mce.2019.110668] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 11/19/2019] [Accepted: 11/26/2019] [Indexed: 02/06/2023]
Abstract
In recent decades, endocrinologists have increasingly adopted evolutionary methods and perspectives to characterize the evolution of the vertebrate endocrine system and leverage it as a model for developing and testing evolutionary theories. This review summarizes recent research on sex steroids (androgens and estrogens) to illustrate three ways in which a detailed understanding of the molecular and cellular architecture of hormonally mediated gene expression can enhance our understanding of general evolutionary principles. By virtue of their massively pleiotropic effects on the expression of genes and phenotypes, sex steroids and their receptors can (1) structure the patterns of phenotypic variance and covariance that are available to natural selection, (2) alter the underlying genetic correlations that determine a population's evolutionary response to selection, and (3) facilitate evolutionary transitions in fitness-related phenotypes via subtle regulatory shifts in underlying tissues and genes. These principles are illustrated by the author's research on testosterone and sexual dimorphism in lizards, and by recent examples drawn from other vertebrate systems. Mechanistically, these examples call attention to the importance of evolutionary changes in (1) androgen- and estrogen-mediated gene expression, (2) androgen and estrogen receptor expression, and (3) the distribution of androgen and estrogen response elements in target genes throughout the genome. A central theme to emerge from this review is that the rapidly increasing availability of genomic and transcriptomic data from non-model organisms places evolutionary endocrinologist in an excellent position to address the hormonal regulation of the key evolutionary interface between genes and phenotypes.
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Affiliation(s)
- Robert M Cox
- Department of Biology, University of Virginia, Charlottesville, VA, 22904, USA.
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Schlinger BA. Multidisciplinary science and the growth and future of behavioral neuroendocrinology: A perspective. Horm Behav 2020; 118:104618. [PMID: 31783027 DOI: 10.1016/j.yhbeh.2019.104618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 01/24/2023]
Affiliation(s)
- Barney A Schlinger
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA; Smithsonian Tropical Research Institute, Panama City, Panama.
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Riebel K, Odom KJ, Langmore NE, Hall ML. New insights from female bird song: towards an integrated approach to studying male and female communication roles. Biol Lett 2019; 15:20190059. [PMID: 30940020 DOI: 10.1098/rsbl.2019.0059] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Historically, bird song has been regarded as a sex-specific signalling trait; males sing to attract females and females drive the evolution of signal exaggeration by preferring males with ever more complex songs. This view provides no functional role for female song. Historic geographical research biases generalized pronounced sex differences of phylogenetically derived northern temperate zone songbirds to all songbirds. However, we now know that female song is common and that both sexes probably sang in the ancestor of modern songbirds. This calls for research on adaptive explanations and mechanisms regulating female song, and a reassessment of questions and approaches to identify selection pressures driving song elaboration in both sexes and subsequent loss of female song in some clades. In this short review and perspective we highlight newly emerging questions and propose a research framework to investigate female song and song sex differences across species. We encourage experimental tests of mechanism, ontogeny, and function integrated with comparative evolutionary analyses. Moreover, we discuss the wider implications of female bird song research for our understanding of male and female communication roles.
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Affiliation(s)
- Katharina Riebel
- 1 Institute of Biology, Leiden University , 2333 BE, Leiden , The Netherlands
| | - Karan J Odom
- 1 Institute of Biology, Leiden University , 2333 BE, Leiden , The Netherlands.,2 Cornell Lab of Ornithology and Department of Neurobiology and Behavior, Cornell University , Ithaca, NY 14850 , USA
| | - Naomi E Langmore
- 3 Research School of Biology, Australian National University , Canberra, Australian Capital Territory 0200 , Australia
| | - Michelle L Hall
- 4 School of BioSciences, University of Melbourne , Melbourne, Victoria 3010 , Australia
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