1
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Qi S, Ngwa C, Al Mamun A, Romana S, Wu T, Marrelli SP, Arnold AP, McCullough LD, Liu F. X, but not Y, Chromosomal Complement Contributes to Stroke Sensitivity in Aged Animals. Transl Stroke Res 2023; 14:776-789. [PMID: 35906327 PMCID: PMC10490444 DOI: 10.1007/s12975-022-01070-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/07/2022] [Accepted: 07/21/2022] [Indexed: 01/16/2023]
Abstract
Post-menopausal women become vulnerable to stroke and have poorer outcomes and higher mortality than age-matched men, and previous studies suggested that sex chromosomes play a vital role in mediating stroke sensitivity in the aged. It is unknown if this is due to effects of the X or Y chromosome. The present study used the XY* mouse model (with four genotypes: XX and XO gonadal females and XY and XXY gonadal males) to compare the effect of the X vs. Y chromosome compliment in stroke. Aged (18-20 months) and gonadectomized young (8-12 weeks) mice were subjected to a 60-min middle cerebral artery occlusion. Infarct volume and behavioral deficits were quantified 3 days after stroke. Microglial activation and infiltration of peripheral leukocytes in the aged ischemic brain were assessed by flow cytometry. Plasma inflammatory cytokine levels by ELISA, and brain expression of two X chromosome-linked genes, KDM6A and KDM5C by immunochemistry, were also examined. Both aged and young XX and XXY mice had worse stroke outcomes compared to XO and XY mice, respectively; however, the difference between XX vs. XXY and XO vs. XY aged mice was minimal. Mice with two copies of the X chromosome showed more robust microglial activation, higher brain-infiltrating leukocytes, elevated plasma cytokine levels, and enhanced co-localization of KDM6A and KDM5C with Iba1+ cells after stroke than mice with one X chromosome. The number of X chromosomes mediates stroke sensitivity in aged mice, which might be processed through the X chromosome-linked genes and the inflammatory responses.
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Affiliation(s)
- Shaohua Qi
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Conelius Ngwa
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Abdullah Al Mamun
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Sharmeen Romana
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Ting Wu
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Sean P Marrelli
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Arthur P Arnold
- Department of Integrative Biology and Physiology, UCLA, 610 Charles Young Drive South, Los Angeles, CA, 90095, USA
| | - Louise D McCullough
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA
| | - Fudong Liu
- Department of Neurology, McGovern Medical School, The University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin Street, Houston, TX, 77030, USA.
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2
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Richardson V, Engel N, Kulathinal RJ. Comparative developmental genomics of sex-biased gene expression in early embryogenesis across mammals. Biol Sex Differ 2023; 14:30. [PMID: 37208698 DOI: 10.1186/s13293-023-00520-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/15/2023] [Indexed: 05/21/2023] Open
Abstract
BACKGROUND Mammalian gonadal sex is determined by the presence or absence of a Y chromosome and the subsequent production of sex hormones contributes to secondary sexual differentiation. However, sex chromosome-linked genes encoding dosage-sensitive transcription and epigenetic factors are expressed well before gonad formation and have the potential to establish sex-biased expression that persists beyond the appearance of gonadal hormones. Here, we apply a comparative bioinformatics analysis on a pair of published single-cell datasets from mouse and human during very early embryogenesis-from two-cell to pre-implantation stages-to characterize sex-specific signals and to assess the degree of conservation among early acting sex-specific genes and pathways. RESULTS Clustering and regression analyses of gene expression across samples reveal that sex initially plays a significant role in overall gene expression patterns at the earliest stages of embryogenesis which potentially may be the byproduct of signals from male and female gametes during fertilization. Although these transcriptional sex effects rapidly diminish, sex-biased genes appear to form sex-specific protein-protein interaction networks across pre-implantation stages in both mammals providing evidence that sex-biased expression of epigenetic enzymes may establish sex-specific patterns that persist beyond pre-implantation. Non-negative matrix factorization (NMF) on male and female transcriptomes generated clusters of genes with similar expression patterns across sex and developmental stages, including post-fertilization, epigenetic, and pre-implantation ontologies conserved between mouse and human. While the fraction of sex-differentially expressed genes (sexDEGs) in early embryonic stages is similar and functional ontologies are conserved, the genes involved are generally different in mouse and human. CONCLUSIONS This comparative study uncovers much earlier than expected sex-specific signals in mouse and human embryos that pre-date hormonal signaling from the gonads. These early signals are diverged with respect to orthologs yet conserved in terms of function with important implications in the use of genetic models for sex-specific disease.
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Affiliation(s)
- Victorya Richardson
- Department of Biology, Temple University, 1900 N. 12th Street, Philadelphia, PA, 19122, USA
| | - Nora Engel
- Department of Cancer Biology, Lewis Katz School of Medicine, Fels Cancer Institute for Personalized Medicine, Temple University, 3400 N. Broad Street, Philadelphia, PA, 19140, USA.
| | - Rob J Kulathinal
- Department of Biology, Temple University, 1900 N. 12th Street, Philadelphia, PA, 19122, USA.
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA, 19122, USA.
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3
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Fusco G, Minelli A. Descriptive versus causal morphology: gynandromorphism and intersexuality. Theory Biosci 2023; 142:1-11. [PMID: 36633802 PMCID: PMC9925516 DOI: 10.1007/s12064-023-00385-1] [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: 10/05/2021] [Accepted: 01/02/2023] [Indexed: 01/13/2023]
Abstract
In animal species with separate sexes, abnormal individuals with a mix of phenotypically male and phenotypically female body parts are generally indicated as gynandromorphs, whereas individuals with intermediate sexual phenotypic traits are generally indicated as intersexes. However, this distinction, clear as it may seem, is neither universally agreed upon, nor free of critical issues. In consideration of the role of sex anomalies in understanding normal development, we reassess these phenomena of abnormal sexual development, taking into consideration the more recent advances in the study of sex determination and sexual differentiation. We argue that a distinction between gynandromorphism and intersexuality, although useful for descriptive purposes, is not always possible or sensible. We discuss the conceptual and terminological intricacies of the literature on this subject and provide reasons for largely, although not strictly, preferring a terminology based on descriptive rather than causal morphology, that is, on the observed phenotypic patterns rather on the causal process behind them.
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Affiliation(s)
- Giuseppe Fusco
- Department of Biology, University of Padova, Padua, Italy.
| | - Alessandro Minelli
- grid.5608.b0000 0004 1757 3470Department of Biology, University of Padova, Padua, Italy
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4
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Cheng Y, Zhang Z, Zhang G, Chen L, Zeng C, Liu X, Feng Y. The Male-Biased Expression of miR-2954 Is Involved in the Male Pathway of Chicken Sex Differentiation. Cells 2022; 12:cells12010004. [PMID: 36611798 PMCID: PMC9818168 DOI: 10.3390/cells12010004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/26/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
Many expression data showed miRNAs have a potential function on regulating gonadal differentiation in animals, but their function is rarely studied in vivo, especially in chickens. Using the comprehensive expression profiles analysis, the specific male-biased miR-2954, which is significantly higher expressed in male embryos and gonads at all detected stages, was firstly screened during the early stages of chicken embryogenesis and gonadogenesis. In sex-reversed female gonads treated with aromatase inhibitors, the expression of miR-2954 was increased, which was consistent with the up-regulation of DMRT1 and SOX9. The injection of vivo-morpholino of miR-2954 significantly inhibited the expression of miR-2954 in chicken embryos, and the down-regulation of miR-2954 decreased the expression of testis-associated genes DMRT1 and SOX9, while the expression of ovary-associated genes and the gonadal morphology did not change obviously. These results confirm that miR-2954 coincides with testicular differentiation in chicken embryos, but whether it might be an upstream cell autonomous factor to sex development in birds still need to be further determined.
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5
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Arnold AP. Integrating Sex Chromosome and Endocrine Theories to Improve Teaching of Sexual Differentiation. Cold Spring Harb Perspect Biol 2022; 14:a039057. [PMID: 35667790 PMCID: PMC9438782 DOI: 10.1101/cshperspect.a039057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Major sex differences in mammalian tissues are functionally tied to reproduction and evolved as adaptations to meet different reproductive needs of females and males. They were thus directly controlled by gonadal hormones. Factors encoded on the sex chromosomes also cause many sex differences in diverse tissues because they are present in different doses in XX and XY cells. The sex chromosome effects likely evolved not because of demands of reproduction, but as side effects of genomic forces that adaptively reduced sexual inequality. Sex-specific effects of particular factors, including gonadal hormones, therefore, are not necessarily explained as adaptations for reproduction, but also as potential factors offsetting, rather than producing, sex differences. The incorporation of these concepts would improve future teaching about sexual differentiation.
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Affiliation(s)
- Arthur P Arnold
- Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California 90095-7239, USA
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6
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Blencowe M, Chen X, Zhao Y, Itoh Y, McQuillen CN, Han Y, Shou BL, McClusky R, Reue K, Arnold AP, Yang X. Relative contributions of sex hormones, sex chromosomes, and gonads to sex differences in tissue gene regulation. Genome Res 2022; 32:807-824. [PMID: 35396276 PMCID: PMC9104702 DOI: 10.1101/gr.275965.121] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 03/29/2022] [Indexed: 11/25/2022]
Abstract
Sex differences in physiology and disease in mammals result from the effects of three classes of factors that are inherently unequal in males and females: reversible (activational) effects of gonadal hormones, permanent (organizational) effects of gonadal hormones, and cell-autonomous effects of sex chromosomes, as well as genes driven by these classes of factors. Often, these factors act together to cause sex differences in specific phenotypes, but the relative contribution of each and the interactions among them remain unclear. Here, we used the four core genotypes (FCG) mouse model with or without hormone replacement to distinguish the effects of each class of sex-biasing factors on transcriptome regulation in liver and adipose tissues. We found that the activational hormone levels have the strongest influence on gene expression, followed by the organizational gonadal sex effect, and last, sex chromosomal effect, along with interactions among the three factors. Tissue specificity was prominent, with a major impact of estradiol on adipose tissue gene regulation and of testosterone on the liver transcriptome. The networks affected by the three sex-biasing factors include development, immunity and metabolism, and tissue-specific regulators were identified for these networks. Furthermore, the genes affected by individual sex-biasing factors and interactions among factors are associated with human disease traits such as coronary artery disease, diabetes, and inflammatory bowel disease. Our study offers a tissue-specific account of the individual and interactive contributions of major sex-biasing factors to gene regulation that have broad impact on systemic metabolic, endocrine, and immune functions.
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Affiliation(s)
- Montgomery Blencowe
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Interdepartmental Program of Molecular, Cellular and Integrative Physiology, University of California, Los Angeles, California 90095, USA
| | - Xuqi Chen
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California 90095, USA
| | - Yutian Zhao
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Interdepartmental Program of Molecular, Cellular and Integrative Physiology, University of California, Los Angeles, California 90095, USA
| | - Yuichiro Itoh
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California 90095, USA
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| | - Caden N McQuillen
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
| | - Yanjie Han
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
| | - Benjamin L Shou
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
| | - Rebecca McClusky
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California 90095, USA
| | - Karen Reue
- Department of Human Genetics and Molecular Biology Institute, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| | - Arthur P Arnold
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Interdepartmental Program of Molecular, Cellular and Integrative Physiology, University of California, Los Angeles, California 90095, USA
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, California 90095, USA
| | - Xia Yang
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
- Interdepartmental Program of Molecular, Cellular and Integrative Physiology, University of California, Los Angeles, California 90095, USA
- Department of Human Genetics and Molecular Biology Institute, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, California 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
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7
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Bronikowski AM, Meisel RP, Biga PR, Walters J, Mank JE, Larschan E, Wilkinson GS, Valenzuela N, Conard AM, de Magalhães JP, Duan J, Elias AE, Gamble T, Graze R, Gribble KE, Kreiling JA, Riddle NC. Sex-specific aging in animals: Perspective and future directions. Aging Cell 2022; 21:e13542. [PMID: 35072344 PMCID: PMC8844111 DOI: 10.1111/acel.13542] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/15/2021] [Accepted: 12/11/2021] [Indexed: 12/14/2022] Open
Abstract
Sex differences in aging occur in many animal species, and they include sex differences in lifespan, in the onset and progression of age-associated decline, and in physiological and molecular markers of aging. Sex differences in aging vary greatly across the animal kingdom. For example, there are species with longer-lived females, species where males live longer, and species lacking sex differences in lifespan. The underlying causes of sex differences in aging remain mostly unknown. Currently, we do not understand the molecular drivers of sex differences in aging, or whether they are related to the accepted hallmarks or pillars of aging or linked to other well-characterized processes. In particular, understanding the role of sex-determination mechanisms and sex differences in aging is relatively understudied. Here, we take a comparative, interdisciplinary approach to explore various hypotheses about how sex differences in aging arise. We discuss genomic, morphological, and environmental differences between the sexes and how these relate to sex differences in aging. Finally, we present some suggestions for future research in this area and provide recommendations for promising experimental designs.
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Affiliation(s)
- Anne M. Bronikowski
- Department of Ecology, Evolution, and Organismal BiologyIowa State UniversityAmesIowaUSA
| | - Richard P. Meisel
- Department of Biology and BiochemistryUniversity of HoustonHoustonTexasUSA
| | - Peggy R. Biga
- Department of BiologyThe University of Alabama at BirminghamBirminghamAlabamaUSA
| | - James R. Walters
- Department of Ecology and Evolutionary BiologyThe University of KansasLawrenceKansasUSA
| | - Judith E. Mank
- Department of ZoologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of BioscienceUniversity of ExeterPenrynUK
| | - Erica Larschan
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | | | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal BiologyIowa State UniversityAmesIowaUSA
| | - Ashley Mae Conard
- Department of Computer ScienceCenter for Computational and Molecular BiologyBrown UniversityProvidenceRhode IslandUSA
| | - João Pedro de Magalhães
- Integrative Genomics of Ageing GroupInstitute of Ageing and Chronic DiseaseUniversity of LiverpoolLiverpoolUK
| | | | - Amy E. Elias
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Tony Gamble
- Department of Biological SciencesMarquette UniversityMilwaukeeWisconsinUSA
- Milwaukee Public MuseumMilwaukeeWisconsinUSA
- Bell Museum of Natural HistoryUniversity of MinnesotaSaint PaulMinnesotaUSA
| | - Rita M. Graze
- Department of Biological SciencesAuburn UniversityAuburnAlabamaUSA
| | - Kristin E. Gribble
- Josephine Bay Paul Center for Comparative Molecular Biology and EvolutionMarine Biological LaboratoryWoods HoleMassachusettsUSA
| | - Jill A. Kreiling
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Nicole C. Riddle
- Department of BiologyThe University of Alabama at BirminghamBirminghamAlabamaUSA
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8
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Brandt N, Vierk R, Fester L, Anstötz M, Zhou L, Heilmann LF, Kind S, Steffen P, Rune GM. Sex-specific Difference of Hippocampal Synaptic Plasticity in Response to Sex Neurosteroids. Cereb Cortex 2021; 30:2627-2641. [PMID: 31800024 DOI: 10.1093/cercor/bhz265] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/23/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022] Open
Abstract
Numerous studies provide increasing evidence, which supports the ideas that every cell in the brain of males may differ from those in females due to differences in sex chromosome complement as well as in response to hormonal effects. In this study, we address the question as to whether actions of neurosteroids, thus steroids, which are synthesized and function within the brain, contribute to sex-specific hippocampal synaptic plasticity. We have previously shown that predominantly in the female hippocampus, does inhibition of the conversion of testosterone to estradiol affect synaptic transmission. In this study, we show that testosterone and its metabolite dihydrotestosterone are essential for hippocampal synaptic transmission specifically in males. This also holds true for the density of mushroom spines and of spine synapses. We obtained similar sex-dependent results using primary hippocampal cultures of male and female animals. Since these cultures originated from perinatal animals, our findings argue for sex-dependent differentiation of hippocampal neurons regarding their responsiveness to sex neurosteroids up to birth, which persist during adulthood. Hence, our in vitro findings may point to a developmental effect either directly induced by sex chromosomes or indirectly by fetal testosterone secretion during the perinatal critical period, when developmental sexual priming takes place.
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Affiliation(s)
- Nicola Brandt
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Ricardo Vierk
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Lars Fester
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Max Anstötz
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Lepu Zhou
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Lukas F Heilmann
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Simon Kind
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Paul Steffen
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Gabriele M Rune
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
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9
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Affiliation(s)
- Craig A Smith
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3168, Australia
| | - Andrew T Major
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3168, Australia
| | - Martin A Estermann
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3168, Australia
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10
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Smith CA, Major AT, Estermann MA. The Curious Case of Avian Sex Determination. Trends Genet 2021; 37:496-497. [PMID: 33838938 DOI: 10.1016/j.tig.2021.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 03/18/2021] [Indexed: 10/21/2022]
Abstract
Ioannidis and colleagues show that the gene DMRT1 is the master regulator of testis development in the chicken. Yet, remarkably, when this gene is deleted in genetic males and gonads form ovaries, the body remains male. This debunks the notion that somatic sex is driven primarily by hormones in birds.
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Affiliation(s)
- Craig A Smith
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.
| | - Andrew T Major
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Martin A Estermann
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
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11
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Mousavi SE, Purser GJ, Patil JG. Embryonic Onset of Sexually Dimorphic Heart Rates in the Viviparous Fish, Gambusia holbrooki. Biomedicines 2021; 9:165. [PMID: 33567532 PMCID: PMC7915484 DOI: 10.3390/biomedicines9020165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 12/12/2022] Open
Abstract
In fish, little is known about sex-specific differences in physiology and performance of the heart and whether these differences manifest during development. Here for the first time, the sex-specific heart rates during embryogenesis of Gambusia holbrooki, from the onset of the heart rates (HRs) to just prior to parturition, was investigated using light cardiogram. The genetic sex of the embryos was post-verified using a sex-specific genetic marker. Results reveal that heart rates and resting time significantly increase (p < 0.05) with progressive embryonic development. Furthermore, both ventricular and atrial frequencies of female embryos were significantly higher (p < 0.05) than those of their male sibs at the corresponding developmental stages and remained so at all later developmental stages (p < 0.05). In concurrence, the heart rate and ventricular size of the adult females were also significantly (p < 0.05) higher and larger respectively than those of males. Collectively, the results suggest that the cardiac sex-dimorphism manifests as early as late-organogenesis and persists through adulthood in this species. These findings suggest that the cardiac measurements can be employed to non-invasively sex the developing embryos, well in advance of when their phenotypic sex is discernible. In addition, G. holbrooki could serve as a better model to study comparative vertebrate cardiovascular development as well as to investigate anthropogenic and climatic impacts on heart physiology of this species, that may be sex influenced.
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Affiliation(s)
- Seyed Ehsan Mousavi
- Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, TAS 7053, Australia;
| | - G. John Purser
- Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, TAS 7053, Australia;
| | - Jawahar G. Patil
- Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, TAS 7053, Australia;
- Inland Fisheries Service, New Norfolk, TAS 7140, Australia
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12
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Sexual EDC-ucation: What we Have Learned About Endocrine-Disrupting Chemicals and Reproduction. CURRENT SEXUAL HEALTH REPORTS 2020. [DOI: 10.1007/s11930-020-00269-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Brandt N, Fester L, Rune GM. Neural sex steroids and hippocampal synaptic plasticity. VITAMINS AND HORMONES 2020; 114:125-143. [PMID: 32723541 DOI: 10.1016/bs.vh.2020.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
It was a widely held belief that sex steroids, namely testosterone and 17β-estradiol (E2) of gonadal origin, control synaptic plasticity in the hippocampus. A new paradigm emerged when it was shown that these sex steroids are synthesized in the hippocampus. The inhibition of sex steroids in the hippocampus impairs synaptic plasticity sex-dependently in this region of the brain. In gonadectomized animals and in hippocampal cultures, inhibition of estradiol synthesis in female animals and in cultures from female animals, and inhibition of dihydrotestosterone synthesis in male animals and in cultures of male animals, cause synapse loss and impair LTP in the hippocampus, but not vice versa. Since the hippocampal cultures originated from perinatal animals, and due to the similarity of in vivo and in vitro findings, it appears that hippocampal neurons are differentiated in a sex-specific manner during the perinatal period when sexual imprinting takes place.
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Affiliation(s)
- N Brandt
- Center of Experimental Medicine, Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - L Fester
- Center of Experimental Medicine, Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - G M Rune
- Center of Experimental Medicine, Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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14
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Leitner N, Ben-Shahar Y. The neurogenetics of sexually dimorphic behaviors from a postdevelopmental perspective. GENES BRAIN AND BEHAVIOR 2019; 19:e12623. [PMID: 31674725 DOI: 10.1111/gbb.12623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/08/2019] [Accepted: 10/28/2019] [Indexed: 12/14/2022]
Abstract
Most sexually reproducing animal species are characterized by two morphologically and behaviorally distinct sexes. The genetic, molecular and cellular processes that produce sexual dimorphisms are phylogenetically diverse, though in most cases they are thought to occur early in development. In some species, however, sexual dimorphisms are manifested after development is complete, suggesting the intriguing hypothesis that sex, more generally, might be considered a continuous trait that is influenced by both developmental and postdevelopmental processes. Here, we explore how biological sex is defined at the genetic, neuronal and behavioral levels, its effects on neuronal development and function, and how it might lead to sexually dimorphic behavioral traits in health and disease. We also propose a unifying framework for understanding neuronal and behavioral sexual dimorphisms in the context of both developmental and postdevelopmental, physiological timescales. Together, these two temporally separate processes might drive sex-specific neuronal functions in sexually mature adults, particularly as it pertains to behavior in health and disease.
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Affiliation(s)
- Nicole Leitner
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri
| | - Yehuda Ben-Shahar
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri
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15
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Noguerol J, Roustan PJ, N'Taye M, Delcombel L, Rolland C, Guiraud L, Sagnat D, Edir A, Bonnart C, Denadai-Souza A, Deraison C, Vergnolle N, Racaud-Sultan C. Sexual dimorphism in PAR 2-dependent regulation of primitive colonic cells. Biol Sex Differ 2019; 10:47. [PMID: 31492202 PMCID: PMC6731565 DOI: 10.1186/s13293-019-0262-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 08/26/2019] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Sexual dimorphism in biological responses is a critical knowledge for therapeutic proposals. However, gender differences in intestinal stem cell physiology have been poorly studied. Given the important role of the protease-activated receptor PAR2 in the control of colon epithelial primitive cells and cell cycle genes, we have performed a sex-based comparison of its expression and of the effects of PAR2 activation or knockout on cell proliferation and survival functions. METHODS Epithelial primitive cells isolated from colons from male and female mice were cultured as colonoids, and their number and size were measured. PAR2 activation was triggered by the addition of SLIGRL agonist peptide in the culture medium. PAR2-deficient mice were used to study the impact of PAR2 expression on colon epithelial cell culture and gene expression. RESULTS Colonoids from female mice were more abundant and larger compared to males, and these differences were further increased after PAR2 activation by specific PAR2 agonist peptide. The proliferation of male epithelial cells was lower compared to females but was specifically increased in PAR2 knockout male cells. PAR2 expression was higher in male colon cells compared to females and controlled the gene expression and activation of key negative signals of the primitive cell proliferation. This PAR2-dependent brake on the proliferation of male colon primitive cells was correlated with stress resistance. CONCLUSIONS Altogether, these data demonstrate that there is a sexual dimorphism in the PAR2-dependent regulation of primitive cells of the colon crypt.
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Affiliation(s)
- Julie Noguerol
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Pierre-Jean Roustan
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Mikael N'Taye
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Léo Delcombel
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Corinne Rolland
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Laura Guiraud
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - David Sagnat
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Anissa Edir
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Chrystelle Bonnart
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Alexandre Denadai-Souza
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Céline Deraison
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Nathalie Vergnolle
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France
| | - Claire Racaud-Sultan
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, CHU Purpan, place du Dr Baylac, 31024 Toulouse Cedex 3, Toulouse, France.
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16
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Brandt N, Rune GM. Sex-dependency of oestrogen-induced structural synaptic plasticity: Inhibition of aromatase versus application of estradiol in rodents. Eur J Neurosci 2019; 52:2548-2559. [PMID: 31403726 DOI: 10.1111/ejn.14541] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/19/2019] [Accepted: 08/01/2019] [Indexed: 12/21/2022]
Abstract
Sex-dependent differences in learning and memory formation in humans have been frequently shown. The mechanisms underlying the formation and retention of memories are assumed to involve synaptic plasticity in the hippocampus. Estradiol was shown to effect synaptic plasticity in the hippocampus of rodents. The effects after exogenous application of estradiol to animals frequently produce inconsistent results, in particular, if sex is not considered in the studies. Recently we provided evidence that locally synthesized estradiol plays an essential role on synaptic connectivity in the hippocampus of females but not of male mice. In females, inhibition of local estradiol synthesis leads to synapse loss, which results from impairment of long-term potentiation and dephosphorylation of cofilin, and thereby the destabilization of postsynaptic dendritic spines. This sex-dependency was also seen in the classical aromatase knock-out mouse. Intriguingly, no differences between sexes have been found in a conditional forebrain-specific aromatase knock-out mouse. Altogether, the findings underscore the necessity of including 'Sex as a Biological Variable' in studies of sex steroid-induced synaptic plasticity.
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Affiliation(s)
- Nicola Brandt
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gabriele M Rune
- Institute of Neuroanatomy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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17
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Sex differences in breathing. Comp Biochem Physiol A Mol Integr Physiol 2019; 238:110543. [PMID: 31445081 DOI: 10.1016/j.cbpa.2019.110543] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 01/15/2023]
Abstract
Breathing is a vital behavior that ensures both the adequate supply of oxygen and the elimination of CO2, and it is influenced by many factors. Despite that most of the studies in respiratory physiology rely heavily on male subjects, there is much evidence to suggest that sex is an important factor in the respiratory control system, including the susceptibility for some diseases. These different respiratory responses in males and females may be related to the actions of sex hormones, especially in adulthood. These hormones affect neuromodulatory systems that influence the central medullary rhythm/pontine pattern generator and integrator, sensory inputs to the integrator and motor output to the respiratory muscles. In this article, we will first review the sex dependence on the prevalence of some respiratory-related diseases. Then, we will discuss the role of sex and gonadal hormones in respiratory control under resting conditions and during respiratory challenges, such as hypoxia and hypercapnia, and whether hormonal fluctuations during the estrous/menstrual cycle affect breathing control. We will then discuss the role of the locus coeruleus, a sexually dimorphic CO2/pH-chemosensitive nucleus, on breathing regulation in males and females. Next, we will highlight the studies that exist regarding sex differences in respiratory control during development. Finally, the few existing studies regarding the influence of sex on breathing control in non-mammalian vertebrates will be discussed.
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18
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Abstract
Evolution of genetic mechanisms of sex determination led to two processes causing sex differences in somatic phenotypes: gonadal differentiation and sex chromosome dosage inequality. In species with heteromorphic sex chromosomes, the sex of the individual is established at the time of formation of the zygote, leading to inherent sex differences in expression of sex chromosome genes beginning as soon as the embryonic transcriptome is activated. The inequality of sex chromosome gene expression causes sexual differentiation of the gonads and of non-gonadal tissues. The difference in gonad type in turn causes lifelong differences in gonadal hormones, which interact with unequal effects of X and Y genes acting within cells. Separating the effects of gonadal hormones and sex chromosomes has been possible using mouse models in which gonadal determination is separated from the sex chromosomes, allowing comparison of XX and XY mice with the same type of gonad. Sex differences caused by gonadal hormones and sex chromosomes affect basic physiology and disease mechanisms in most or all tissues.
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19
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Strandqvist A, Herlitz A, Nordenskjöld A, Örtqvist L, Frisén L, Hirschberg AL, Nordenström A. Cognitive abilities in women with complete androgen insensitivity syndrome and women with gonadal dysgenesis. Psychoneuroendocrinology 2018; 98:233-241. [PMID: 29884451 DOI: 10.1016/j.psyneuen.2018.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 04/27/2018] [Accepted: 05/02/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND Many questions regarding the mechanisms behind sex differences in cognitive abilities are still unanswered. On a group level, men typically outperform women on certain spatial tasks, whereas women perform better on certain tests of memory and verbal ability. The prevailing theories concerning the biological predispositions for these and other differences in behaviour and brain function focus on early and prolonged exposure to sex hormones. There is, however, evidence of direct effects of sex chromosomes on sex-typical behaviour in other species. OBJECTIVES To study the influence of sex hormones and sex chromosomes on cognition in women with Complete androgen insensitivity (CAIS) and Gonadal dysgenesis (GD). METHODS Eighteen women with CAIS, 6 women with 46,XYGD, and 7 women with 46,XXGD were compared with age-matched male and female controls on tests of spatial and verbal abilities, memory functions, and emotion recognition. RESULTS Women with CAIS, XYGD, and XXGD performed similar to female controls on cognitive tasks. However, on a test of emotion recognition, women with XXGD outperformed the other groups, whereas women with CAIS and XYGD performed similar to male controls. CONCLUSION Our results support theories of androgen effects on cognitive abilities and suggest that factors related to sex chromosomes may influence emotion recognition. Implications of an atypical sex hormone situation and sex chromosome variation are discussed.
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Affiliation(s)
- Anna Strandqvist
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Pediatric Endocrinology, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
| | - Agneta Herlitz
- Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Agneta Nordenskjöld
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Pediatric Surgery, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
| | - Lisa Örtqvist
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Pediatric Surgery, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
| | - Louise Frisén
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Child and Adolescent Psychiatry Research Center, Stockholm, Sweden.
| | - Angelica Lindén Hirschberg
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Department of Gynecology and Reproductive Medicine, Karolinska University Hospital, Stockholm, Sweden.
| | - Anna Nordenström
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Department of Pediatric Endocrinology, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
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20
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Hilderbrand ER, Lasek AW. Studying Sex Differences in Animal Models of Addiction: An Emphasis on Alcohol-Related Behaviors. ACS Chem Neurosci 2018; 9:1907-1916. [PMID: 29227676 DOI: 10.1021/acschemneuro.7b00449] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Animal models are essential for understanding the biological factors that contribute to drug and alcohol addiction and discovering new pharmacotherapies to treat these disorders. Alcohol (ethanol) is the most commonly abused drug in the world, and as the prevalence of alcohol use disorder (AUD) increases, so does the need for effective pharmacotherapies. In particular, treatments with high efficacy in the growing number of female AUD sufferers are needed. Female animals remain underrepresented in biomedical research and sex differences in the brain's response to alcohol are poorly understood. To help bridge the gender gap in addiction research, this Review discusses strategies that researchers can use to examine sex differences in the context of several common animal models of AUD. Self-administration, two-bottle choice, drinking in the dark, and conditioned place preference are discussed, with a focus on the role of estrogen as a mediator of sex differences in alcohol-related behaviors.
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21
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Caughey SD, Wilson PW, Mukhtar N, Brocklehurst S, Reid A, D'Eath RB, Boswell T, Dunn IC. Sex differences in basal hypothalamic anorectic and orexigenic gene expression and the effect of quantitative and qualitative food restriction. Biol Sex Differ 2018; 9:20. [PMID: 29843787 PMCID: PMC5975468 DOI: 10.1186/s13293-018-0178-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 05/07/2018] [Indexed: 12/18/2022] Open
Abstract
Background Research into energy balance and growth has infrequently considered genetic sex, yet there is sexual dimorphism for growth across the animal kingdom. We test the hypothesis that in the chicken, there is a sex difference in arcuate nucleus neuropeptide gene expression, since previous research indicates hypothalamic AGRP expression is correlated with growth potential and that males grow faster than females. Because growth has been heavily selected in some chicken lines, food restriction is necessary to improve reproductive performance and welfare, but this increases hunger. Dietary dilution has been proposed to ameliorate this undesirable effect. We aimed to distinguish the effects of gut fullness from nutritional feedback on hypothalamic gene expression and its interaction with sex. Methods Twelve-week-old male and female fast-growing chickens were either released from restriction and fed ad libitum or a restricted diet plus 15% w/w ispaghula husk, a non-nutritive bulking agent, for 2 days. A control group remained on quantitative restriction. Hypothalamic arcuate nucleus neuropeptides were measured using real-time PCR. To confirm observed sex differences, the experiment was repeated using only ad libitum and restricted fed fast-growing chickens and in a genetically distinct breed of ad libitum fed male and female chickens. Linear mixed models (Genstat 18) were used for statistical analysis with transformation where appropriate. Results There were pronounced sex differences: expression of the orexigenic genes AGRP (P < 0.001) and NPY (P < 0.002) was higher in males of the fast-growing strain. In genetically distinct chickens, males had higher AGRP mRNA (P = 0.002) expression than females, suggesting sex difference was not restricted to a fast-growing strain. AGRP (P < 0.001) expression was significantly decreased in ad libitum fed birds but was high and indistinguishable between birds on a quantitative versus qualitative restricted diet. Inversely, gene expression of the anorectic genes POMC and CART was significantly higher in ad libitum fed birds but no consistent sex differences were observed. Conclusion Expression of orexigenic peptides in the avian hypothalamus are significantly different between sexes. This could be useful starting point of investigating further if AGRP is an indicator of growth potential. Results also demonstrate that gut fill alone does not reduce orexigenic gene expression. Electronic supplementary material The online version of this article (10.1186/s13293-018-0178-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- S D Caughey
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, EH25 9RG, Scotland, UK.
| | - P W Wilson
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, EH25 9RG, Scotland, UK
| | - N Mukhtar
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, EH25 9RG, Scotland, UK
| | - S Brocklehurst
- Bioinformatics and Statistics Scotland, Edinburgh, Scotland, UK
| | - A Reid
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, EH25 9RG, Scotland, UK
| | - R B D'Eath
- Scotland's Rural College, Edinburgh, Scotland, UK
| | - T Boswell
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, England, UK
| | - I C Dunn
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, EH25 9RG, Scotland, UK
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22
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Arnold AP. A general theory of sexual differentiation. J Neurosci Res 2017; 95:291-300. [PMID: 27870435 DOI: 10.1002/jnr.23884] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/13/2016] [Accepted: 07/25/2016] [Indexed: 12/16/2022]
Abstract
A general theory of mammalian sexual differentiation is proposed. All biological sex differences are the result of the inequality in effects of the sex chromosomes, which are the only factors that differ in XX vs. XY zygotes. This inequality leads to male-specific effects of the Y chromosome, including expression of the testis-determining gene Sry that causes differentiation of testes. Thus, Sry sets up lifelong sex differences in effects of gonadal hormones. Y genes also act outside of the gonads to cause male-specific effects. Differences in the number of X chromosomes between XX and XY cells cause sex differences in expression (1) of Xist, (2) of X genes that escape inactivation, and (3) of parentally imprinted X genes. Sex differences in phenotype are ultimately the result of multiple, independent sex-biasing factors, hormonal and sex chromosomal. These factors act in parallel and in combination to induce sex differences. They also can offset each other to reduce sex differences. Other mechanisms, operating at the level of populations, cause groups of males to differ on average from groups of females. The theory frames questions for further study, and directs attention to inherent sex-biasing factors that operate in many tissues to cause sex differences, and to cause sex-biased protection from disease. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Arthur P Arnold
- Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, Los Angeles, California
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23
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Sawala A, Gould AP. The sex of specific neurons controls female body growth in Drosophila. PLoS Biol 2017; 15:e2002252. [PMID: 28976974 PMCID: PMC5627897 DOI: 10.1371/journal.pbio.2002252] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 09/11/2017] [Indexed: 11/18/2022] Open
Abstract
Sexual dimorphisms in body size are widespread throughout the animal kingdom but their underlying mechanisms are not well characterized. Most models for how sex chromosome genes specify size dimorphism have emphasized the importance of gonadal hormones and cell-autonomous influences in mammals versus strictly cell-autonomous mechanisms in Drosophila melanogaster. Here, we use tissue-specific genetics to investigate how sexual size dimorphism (SSD) is established in Drosophila. We find that the larger body size characteristic of Drosophila females is established very early in larval development via an increase in the growth rate per unit of body mass. We demonstrate that the female sex determination gene, Sex-lethal (Sxl), functions in central nervous system (CNS) neurons as part of a relay that specifies the early sex-specific growth trajectories of larval but not imaginal tissues. Neuronal Sxl acts additively in 2 neuronal subpopulations, one of which corresponds to 7 median neurosecretory cells: the insulin-producing cells (IPCs). Surprisingly, however, male-female differences in the production of insulin-like peptides (Ilps) from the IPCs do not appear to be involved in establishing SSD in early larvae, although they may play a later role. These findings support a relay model in which Sxl in neurons and Sxl in local tissues act together to specify the female-specific growth of the larval body. They also reveal that, even though the sex determination pathways in Drosophila and mammals are different, they both modulate body growth via a combination of tissue-autonomous and nonautonomous inputs.
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Affiliation(s)
| | - Alex P. Gould
- The Francis Crick Institute, London, United Kingdom
- * E-mail:
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24
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Abstract
Men and women exhibit significant differences in obesity, cardiovascular disease, and diabetes. To provide better diagnosis and treatment for both sexes, it is important to identify factors that underlie the observed sex differences. Traditionally, sex differences have been attributed to the differential effects of male and female gonadal secretions (commonly referred to as sex hormones), which substantially influence many aspects of metabolism and related diseases. Less appreciated as a contributor to sex differences are the fundamental genetic differences between males and females, which are ultimately determined by the presence of an XX or XY sex chromosome complement. Here, we review the mechanisms by which gonadal hormones and sex chromosome complement each contribute to lipid metabolism and associated diseases, and the current approaches that are used to study them. We focus particularly on genetic approaches including genome-wide association studies in humans and mice, -omics and systems genetics approaches, and unique experimental mouse models that allow distinction between gonadal and sex chromosome effects.
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Affiliation(s)
- Jenny C Link
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, California 90095;
| | - Karen Reue
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, California 90095;
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California 90095
- Molecular Biology Institute, University of California, Los Angeles, California 90095
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25
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Vertebrate sex determination: evolutionary plasticity of a fundamental switch. Nat Rev Genet 2017; 18:675-689. [DOI: 10.1038/nrg.2017.60] [Citation(s) in RCA: 253] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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26
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Arnold AP, Cassis LA, Eghbali M, Reue K, Sandberg K. Sex Hormones and Sex Chromosomes Cause Sex Differences in the Development of Cardiovascular Diseases. Arterioscler Thromb Vasc Biol 2017; 37:746-756. [PMID: 28279969 DOI: 10.1161/atvbaha.116.307301] [Citation(s) in RCA: 208] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 02/15/2017] [Indexed: 12/25/2022]
Abstract
This review summarizes recent evidence concerning hormonal and sex chromosome effects in obesity, atherosclerosis, aneurysms, ischemia/reperfusion injury, and hypertension. Cardiovascular diseases occur and progress differently in the 2 sexes, because biological factors differing between the sexes have sex-specific protective and harmful effects. By comparing the 2 sexes directly, and breaking down sex into its component parts, one can discover sex-biasing protective mechanisms that might be targeted in the clinic. Gonadal hormones, especially estrogens and androgens, have long been found to account for some sex differences in cardiovascular diseases, and molecular mechanisms mediating these effects have recently been elucidated. More recently, the inherent sexual inequalities in effects of sex chromosome genes have also been implicated as contributors in animal models of cardiovascular diseases, especially a deleterious effect of the second X chromosome found in females but not in males. Hormonal and sex chromosome mechanisms interact in the sex-specific control of certain diseases, sometimes by opposing the action of the other.
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Affiliation(s)
- Arthur P Arnold
- From the Department of Integrative Biology and Physiology, University of California, Los Angeles (A.P.A.); Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington (L.A.C.); Department of Anesthesiology (M.E.) and Department of Human Genetics (K.R.), David Geffen School of Medicine at UCLA, Los Angeles, CA; and Department of Medicine, Georgetown University Medical Center, Washington, DC (K.S.).
| | - Lisa A Cassis
- From the Department of Integrative Biology and Physiology, University of California, Los Angeles (A.P.A.); Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington (L.A.C.); Department of Anesthesiology (M.E.) and Department of Human Genetics (K.R.), David Geffen School of Medicine at UCLA, Los Angeles, CA; and Department of Medicine, Georgetown University Medical Center, Washington, DC (K.S.)
| | - Mansoureh Eghbali
- From the Department of Integrative Biology and Physiology, University of California, Los Angeles (A.P.A.); Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington (L.A.C.); Department of Anesthesiology (M.E.) and Department of Human Genetics (K.R.), David Geffen School of Medicine at UCLA, Los Angeles, CA; and Department of Medicine, Georgetown University Medical Center, Washington, DC (K.S.)
| | - Karen Reue
- From the Department of Integrative Biology and Physiology, University of California, Los Angeles (A.P.A.); Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington (L.A.C.); Department of Anesthesiology (M.E.) and Department of Human Genetics (K.R.), David Geffen School of Medicine at UCLA, Los Angeles, CA; and Department of Medicine, Georgetown University Medical Center, Washington, DC (K.S.)
| | - Kathryn Sandberg
- From the Department of Integrative Biology and Physiology, University of California, Los Angeles (A.P.A.); Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington (L.A.C.); Department of Anesthesiology (M.E.) and Department of Human Genetics (K.R.), David Geffen School of Medicine at UCLA, Los Angeles, CA; and Department of Medicine, Georgetown University Medical Center, Washington, DC (K.S.)
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27
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Acaz-Fonseca E, Ortiz-Rodriguez A, Lopez-Rodriguez AB, Garcia-Segura LM, Astiz M. Developmental Sex Differences in the Metabolism of Cardiolipin in Mouse Cerebral Cortex Mitochondria. Sci Rep 2017; 7:43878. [PMID: 28262723 PMCID: PMC5338321 DOI: 10.1038/srep43878] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/25/2017] [Indexed: 01/15/2023] Open
Abstract
Cardiolipin (CL) is a mitochondrial-specific phospholipid. CL content and acyl chain composition are crucial for energy production. Given that estradiol induces CL synthesis in neurons, we aimed to assess CL metabolism in the cerebral cortex (CC) of male and female mice during early postnatal life, when sex steroids induce sex-dimorphic maturation of the brain. Despite the fact that total amount of CL was similar, its fatty acid composition differed between males and females at birth. In males, CL was more mature (lower saturation ratio) and the expression of the enzymes involved in synthetic and remodeling pathways was higher, compared to females. Importantly, the sex differences found in CL metabolism were due to the testosterone peak that male mice experience perinatally. These changes were associated with a higher expression of UCP-2 and its activators in the CC of males. Overall, our results suggest that the perinatal testosterone surge in male mice regulates CL biosynthesis and remodeling in the CC, inducing a sex-dimorphic fatty acid composition. In male's CC, CL is more susceptible to peroxidation, likely explaining the testosterone-dependent induction of neuroprotective molecules such as UCP-2. These differences may account for the sex-dependent mitochondrial susceptibility after perinatal hypoxia/ischemia.
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Affiliation(s)
| | | | | | | | - Mariana Astiz
- Instituto Cajal-CSIC. Avenida Doctor Arce 37, 28002 Madrid, Spain
- Biochemistry Research Institute of La Plata (INIBIOLP), CONICET. 60 and 120, 1900, La Plata, Argentina
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28
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Link JC, Hasin-Brumshtein Y, Cantor RM, Chen X, Arnold AP, Lusis AJ, Reue K. Diet, gonadal sex, and sex chromosome complement influence white adipose tissue miRNA expression. BMC Genomics 2017; 18:89. [PMID: 28095800 PMCID: PMC5240420 DOI: 10.1186/s12864-017-3484-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 01/10/2017] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression by targeting specific mRNA species for degradation or interfering with translation. Specific miRNAs are key regulators of adipogenesis, and are expressed at different levels in adipose tissue from lean and obese mice. The degree of lipid accumulation and distribution of white adipose tissue differs between males and females, and it is unknown whether sex differences in adipose tissue-specific miRNA expression may contribute to this dimorphism. Typically, sex differences are attributed to hormones secreted from ovaries or testes. However, the sex chromosome complement (XX versus XY) is also a determinant of sex differences and may regulate miRNA expression in adipocytes. RESULTS To identify sex differences in adipose tissue miRNA expression and to understand the underlying mechanisms, we performed high-throughput miRNA sequencing in gonadal fat depots of the Four Core Genotypes mouse model. This model, which consists of XX female, XX male, XY female, and XY male mice, allowed us to assess independent effects of gonadal type (male vs. female) and sex chromosome complement (XX vs. XY) on miRNA expression profiles. We have also assessed the effects of a high fat diet on sex differences in adipose tissue miRNA profiles. We identified a male-female effect on the overall miRNA expression profile in mice fed a chow diet, with a bias toward higher expression in male compared to female gonadal adipose tissue. This sex bias disappeared after gonadectomy, suggesting that circulating levels of gonadal secretions modulate the miRNA expression profile. After 16 weeks of high fat diet, the miRNA expression distribution was shifted toward higher expression in XY vs. XX adipose tissue. Principal component analysis revealed that high fat diet has a substantial effect on miRNA profile variance, while gonadal secretions and sex chromosome complement each have milder effects. CONCLUSIONS Our results demonstrate that the overall miRNA expression profile in adipose tissue is influenced by gonadal hormones and the sex chromosome complement, and that expression profiles change in response to gonadectomy and high fat diet. Differential miRNA expression profiles may contribute to sex differences in adipose tissue gene expression, adipose tissue development, and diet-induced obesity.
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Affiliation(s)
- Jenny C Link
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Yehudit Hasin-Brumshtein
- Department of Medicine, David Geffen School of Medicine, University of California, 90095, Los Angeles, CA, USA
| | - Rita M Cantor
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Xuqi Chen
- Department of Integrative Biology and Physiology, University of California, 90095, Los Angeles, CA, USA.,Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, 90095, Los Angeles, CA, USA
| | - Arthur P Arnold
- Department of Integrative Biology and Physiology, University of California, 90095, Los Angeles, CA, USA.,Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, 90095, Los Angeles, CA, USA
| | - Aldons J Lusis
- Department of Medicine, David Geffen School of Medicine, University of California, 90095, Los Angeles, CA, USA
| | - Karen Reue
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA. .,Molecular Biology Institute, University of California, 90095, Los Angeles, CA, USA.
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Joel D, McCarthy MM. Incorporating Sex As a Biological Variable in Neuropsychiatric Research: Where Are We Now and Where Should We Be? Neuropsychopharmacology 2017; 42:379-385. [PMID: 27240659 PMCID: PMC5399245 DOI: 10.1038/npp.2016.79] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 05/17/2016] [Accepted: 05/23/2016] [Indexed: 11/09/2022]
Abstract
Understanding the multiplicity of ways in which sex can alter the brain is essential to crafting policies and treatments that are beneficial for all human beings. This is particularly true for the field of neuropsychopharmacology, as many neuropsychiatric disorders exhibit gender bias in the frequency, severity, or response to treatment. The goal of this circumspective is to provide two views on the current state of the art of the relations between sex and the brain, relations that are studied almost exclusively by comparing females and males on specific end points, from gene expression to behavior. We start by suggesting a framework for defining what is being measured and what it means. We suggest that 'sex differences' can be classified on four dimensions: (1) persistent vs transient across the lifespan; (2) context independent vs dependent; (3) dimorphic vs continuous; and (4) a direct vs an indirect consequence of sex. To accurately classify a sex difference along these dimensions, one may need to compare females and males under varied conditions. We next discuss current data on the mechanisms of sexual differentiation of the brain and on sex differences in the brain to conclude that the brain of each male and female is a mosaic of relative masculinization, feminization, and sameness, which theoretically could produce an infinite variety of individuals. We also raise the possibility that sex differences in the brain are canalized, which may act to both enhance and restrain variation between males and females. We end by discussing ways to consider sex when studying neuropsychiatric disorders.
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Affiliation(s)
- Daphna Joel
- School of Psychological Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel,School of Psychological Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel, Tel: +972 3 640 8996, Fax: +972 3 640 9547, E-mail:
| | - Margaret M McCarthy
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Burgoyne PS, Arnold AP. A primer on the use of mouse models for identifying direct sex chromosome effects that cause sex differences in non-gonadal tissues. Biol Sex Differ 2016; 7:68. [PMID: 27999654 PMCID: PMC5154145 DOI: 10.1186/s13293-016-0115-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 11/08/2016] [Indexed: 12/15/2022] Open
Abstract
In animals with heteromorphic sex chromosomes, all sex differences originate from the sex chromosomes, which are the only factors that are consistently different in male and female zygotes. In mammals, the imbalance in Y gene expression, specifically the presence vs. absence of Sry, initiates the differentiation of testes in males, setting up lifelong sex differences in the level of gonadal hormones, which in turn cause many sex differences in the phenotype of non-gonadal tissues. The inherent imbalance in the expression of X and Y genes, or in the epigenetic impact of X and Y chromosomes, also has the potential to contribute directly to the sexual differentiation of non-gonadal cells. Here, we review the research strategies to identify the X and Y genes or chromosomal regions that cause direct, sexually differentiating effects on non-gonadal cells. Some mouse models are useful for separating the effects of sex chromosomes from those of gonadal hormones. Once direct “sex chromosome effects” are detected in these models, further studies are required to narrow down the list of candidate X and/or Y genes and then to identify the sexually differentiating genes themselves. Logical approaches to the search for these genes are reviewed here.
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Affiliation(s)
- Paul S Burgoyne
- Stem Cell Biology and Developmental Genetics, Mill Hill Laboratory, Francis Crick Institute, The Ridgeway, London, NW7 1AA UK
| | - Arthur P Arnold
- Department of Integrative Biology and Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, 610 Charles Young Drive South, Los Angeles, CA 90095-7239 USA
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Miller LR, Marks C, Becker JB, Hurn PD, Chen WJ, Woodruff T, McCarthy MM, Sohrabji F, Schiebinger L, Wetherington CL, Makris S, Arnold AP, Einstein G, Miller VM, Sandberg K, Maier S, Cornelison TL, Clayton JA. Considering sex as a biological variable in preclinical research. FASEB J 2016; 31:29-34. [PMID: 27682203 DOI: 10.1096/fj.201600781r] [Citation(s) in RCA: 242] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/22/2016] [Indexed: 11/11/2022]
Abstract
In June 2015, the National Institutes of Health (NIH) released a Guide notice (NOT-OD-15-102) that highlighted the expectation of the NIH that the possible role of sex as a biologic variable be factored into research design, analyses, and reporting of vertebrate animal and human studies. Anticipating these guidelines, the NIH Office of Research on Women's Health, in October 2014, convened key stakeholders to discuss methods and techniques for integrating sex as a biologic variable in preclinical research. The workshop focused on practical methods, experimental design, and approaches to statistical analyses in the use of both male and female animals, cells, and tissues in preclinical research. Workshop participants also considered gender as a modifier of biology. This article builds on the workshop and is meant as a guide to preclinical investigators as they consider methods and techniques for inclusion of both sexes in preclinical research and is not intended to prescribe exhaustive/specific approaches for compliance with the new NIH policy.-Miller, L. R., Marks, C., Becker, J. B., Hurn, P. D., Chen, W.-J., Woodruff, T., McCarthy, M. M., Sohrabji, F., Schiebinger, L., Wetherington, C. L., Makris, S., Arnold, A. P., Einstein, G., Miller, V. M., Sandberg, K., Maier, S., Cornelison, T. L., Clayton, J. A. Considering sex as a biological variable in preclinical research.
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Affiliation(s)
- Leah R Miller
- Office of Research on Women's Health, National Institutes of Health, Bethesda, Maryland, USA;
| | - Cheryl Marks
- Division of Cancer Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jill B Becker
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Patricia D Hurn
- School of Nursing, University of Michigan, Ann Arbor, Michigan, USA
| | - Wei-Jung Chen
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, Texas, USA
| | - Teresa Woodruff
- Women's Health Research Institute, Northwestern University, Chicago, Illinois, USA
| | - Margaret M McCarthy
- Department of Pharmacology, University of Maryland, Baltimore, Maryland, USA
| | - Farida Sohrabji
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, Texas, USA
| | | | - Cora Lee Wetherington
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland, USA
| | - Susan Makris
- Office of Research and Development, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington, D.C., USA
| | - Arthur P Arnold
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California, USA.,Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Gillian Einstein
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada.,The Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.,Women's College Research Institute, Toronto, Ontario, Canada
| | - Virginia M Miller
- Department of Surgery and Physiology, Mayo Clinic, Rochester, Minnesota, USA.,Department of Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Kathryn Sandberg
- Department of Medicine, Georgetown University Medical Center, Washington, D.C., USA.,Center for the Study of Sex Differences in Health, Aging and Disease, Georgetown University Medical Center, Washington, D.C., USA
| | - Susan Maier
- Office of Research on Women's Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Terri L Cornelison
- Office of Research on Women's Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Janine A Clayton
- Office of Research on Women's Health, National Institutes of Health, Bethesda, Maryland, USA
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Acaz-Fonseca E, Avila-Rodriguez M, Garcia-Segura LM, Barreto GE. Regulation of astroglia by gonadal steroid hormones under physiological and pathological conditions. Prog Neurobiol 2016; 144:5-26. [DOI: 10.1016/j.pneurobio.2016.06.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 06/05/2016] [Indexed: 01/07/2023]
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Parma P, Veyrunes F, Pailhoux E. Sex Reversal in Non-Human Placental Mammals. Sex Dev 2016; 10:326-344. [PMID: 27529721 DOI: 10.1159/000448361] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 01/31/2023] Open
Abstract
Gonads are very peculiar organs given their bipotential competence. Indeed, early differentiating genital ridges evolve into either of 2 very distinct organs: the testis or the ovary. Accumulating evidence now demonstrates that both genetic pathways must repress the other in order for the organs to differentiate properly, meaning that if this repression is disrupted or attenuated, the other pathway may completely or partially be expressed, leading to disorders of sex development. Among these disorders are the cases of XY male-to-female and XX female-to-male sex reversals as well as true hermaphrodites, in which there is a discrepancy between the chromosomal and gonadal sex. Here, we review known cases of XY and XX sex reversals described in mammals, focusing mostly on domestic animals where sex reversal pathologies occur and on wild species in which deviations from the usual XX/XY system have been documented.
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Affiliation(s)
- Pietro Parma
- Department of Agricultural and Environmental Sciences, Milan University, Milan, Italy
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Abstract
While sex differences in hormonal regulation of development and tissue maintenance are well established, the importance of genetic sex determination in adult lineages remains largely unexplored. Two studies now report that reversing the genetic sex of progenitors or differentiated cells in the fly intestine dramatically affects epithelial homeostasis and longevity.
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Affiliation(s)
- Douglas S Portman
- Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Benoît Biteau
- Department of Biomedical Genetics, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA.
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36
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McCarthy MM, Pickett LA, VanRyzin JW, Kight KE. Surprising origins of sex differences in the brain. Horm Behav 2015; 76:3-10. [PMID: 25917865 PMCID: PMC4620061 DOI: 10.1016/j.yhbeh.2015.04.013] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/22/2015] [Accepted: 04/06/2015] [Indexed: 11/22/2022]
Abstract
This article is part of a Special Issue "SBN 2014". Discerning the biologic origins of neuroanatomical sex differences has been of interest since they were first reported in the late 60's and early 70's. The centrality of gonadal hormone exposure during a developmental critical window cannot be denied but hormones are indirect agents of change, acting to induce gene transcription or modulate membrane bound signaling cascades. Sex differences in the brain include regional volume differences due to differential cell death, neuronal and glial genesis, dendritic branching and synaptic patterning. Early emphasis on mechanism therefore focused on neurotransmitters and neural growth factors, but by and large these endpoints failed to explain the origins of neural sex differences. More recently evidence has accumulated in favor of inflammatory mediators and immune cells as principle regulators of brain sexual differentiation and reveal that the establishment of dimorphic circuits is not cell autonomous but instead requires extensive cell-to-cell communication including cells of non-neuronal origin. Despite the multiplicity of cells involved the nature of the sex differences in the neuroanatomical endpoints suggests canalization, a process that explains the robustness of individuals in the face of intrinsic and extrinsic variability. We propose that some neuroanatomical endpoints are canalized to enhance sex differences in the brain by reducing variability within one sex while also preventing the sexes from diverging too greatly. We further propose mechanisms by which such canalization could occur and discuss what relevance this may have to sex differences in behavior.
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Affiliation(s)
- Margaret M McCarthy
- Department of Pharmacology, Program in Neuroscience and Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Lindsay A Pickett
- Department of Pharmacology, Program in Neuroscience and Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Jonathan W VanRyzin
- Department of Pharmacology, Program in Neuroscience and Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Katherine E Kight
- Department of Pharmacology, Program in Neuroscience and Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Chen X, Wang L, Loh DH, Colwell CS, Taché Y, Reue K, Arnold AP. Sex differences in diurnal rhythms of food intake in mice caused by gonadal hormones and complement of sex chromosomes. Horm Behav 2015; 75:55-63. [PMID: 26226656 PMCID: PMC4648666 DOI: 10.1016/j.yhbeh.2015.07.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 07/13/2015] [Accepted: 07/23/2015] [Indexed: 01/10/2023]
Abstract
We measured diurnal rhythms of food intake, as well as body weight and composition, while varying three major classes of sex-biasing factors: activational and organizational effects of gonadal hormones, and sex chromosome complement (SCC). Four Core Genotypes (FCG) mice, comprising XX and XY gonadal males and XX and XY gonadal females, were either gonad-intact or gonadectomized (GDX) as adults (2.5months); food intake was measured second-by-second for 7days starting 5weeks later, and body weight and composition were measured for 22weeks thereafter. Gonadal males weighed more than females. GDX increased body weight/fat of gonadal females, but increased body fat and reduced body weight of males. After GDX, XX mice had greater body weight and more fat than XY mice. In gonad-intact mice, males had greater total food intake and more meals than females during the dark phase, but females had more food intake and meals and larger meals than males during the light phase. GDX reduced overall food intake irrespective of gonad type or SCC, and eliminated differences in feeding between groups with different gonads. Diurnal phase of feeding was influenced by all three sex-biasing variables. Gonad-intact females had earlier onset and acrophase (peak) of feeding relative to males. GDX caused a phase-advance of feeding, especially in XX mice, leading to an earlier onset of feeding in GDX XX vs. XY mice, but earlier acrophase in GDX males relative to females. Gonadal hormones and SCC interact in the control of diurnal rhythms of food intake.
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Affiliation(s)
- Xuqi Chen
- Department of Integrative Biology & Physiology, University of California, Los Angeles, CA, USA; Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA.
| | - Lixin Wang
- CURE/Digestive Diseases Research Center and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Los Angeles, CA, 90073, USA.
| | - Dawn H Loh
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
| | - Christopher S Colwell
- Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
| | - Yvette Taché
- CURE/Digestive Diseases Research Center and Center for the Neurobiology of Stress, Department of Medicine, Division of Digestive Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Los Angeles, CA, 90073, USA.
| | - Karen Reue
- Department of Human Genetics and Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles CA, USA.
| | - Arthur P Arnold
- Department of Integrative Biology & Physiology, University of California, Los Angeles, CA, USA; Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, CA, USA.
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Schmid M, Smith J, Burt DW, Aken BL, Antin PB, Archibald AL, Ashwell C, Blackshear PJ, Boschiero C, Brown CT, Burgess SC, Cheng HH, Chow W, Coble DJ, Cooksey A, Crooijmans RPMA, Damas J, Davis RVN, de Koning DJ, Delany ME, Derrien T, Desta TT, Dunn IC, Dunn M, Ellegren H, Eöry L, Erb I, Farré M, Fasold M, Fleming D, Flicek P, Fowler KE, Frésard L, Froman DP, Garceau V, Gardner PP, Gheyas AA, Griffin DK, Groenen MAM, Haaf T, Hanotte O, Hart A, Häsler J, Hedges SB, Hertel J, Howe K, Hubbard A, Hume DA, Kaiser P, Kedra D, Kemp SJ, Klopp C, Kniel KE, Kuo R, Lagarrigue S, Lamont SJ, Larkin DM, Lawal RA, Markland SM, McCarthy F, McCormack HA, McPherson MC, Motegi A, Muljo SA, Münsterberg A, Nag R, Nanda I, Neuberger M, Nitsche A, Notredame C, Noyes H, O'Connor R, O'Hare EA, Oler AJ, Ommeh SC, Pais H, Persia M, Pitel F, Preeyanon L, Prieto Barja P, Pritchett EM, Rhoads DD, Robinson CM, Romanov MN, Rothschild M, Roux PF, Schmidt CJ, Schneider AS, Schwartz MG, Searle SM, Skinner MA, Smith CA, Stadler PF, Steeves TE, Steinlein C, Sun L, Takata M, Ulitsky I, Wang Q, Wang Y, Warren WC, Wood JMD, Wragg D, Zhou H. Third Report on Chicken Genes and Chromosomes 2015. Cytogenet Genome Res 2015; 145:78-179. [PMID: 26282327 PMCID: PMC5120589 DOI: 10.1159/000430927] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Michael Schmid
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
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Itoh Y, Mackie R, Kampf K, Domadia S, Brown JD, O’Neill R, Arnold AP. Four core genotypes mouse model: localization of the Sry transgene and bioassay for testicular hormone levels. BMC Res Notes 2015; 8:69. [PMID: 25870930 PMCID: PMC4354741 DOI: 10.1186/s13104-015-0986-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 01/20/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The "four core genotypes" (FCG) mouse model has emerged as a major model testing if sex differences in phenotypes are caused by sex chromosome complement (XX vs. XY) or gonadal hormones or both. The model involves deletion of the testis-determining gene Sry from the Y chromosome and insertion of an Sry transgene onto an autosome. It produces XX and XY mice with testes, and XX and XY mice with ovaries, so that XX and XY mice with the same type of gonad can be compared to assess phenotypic effects of sex chromosome complement in cells and tissues. FINDINGS We used PCR to amplify the Sry transgene and adjacent genomic sequences, to resolve the location of the Sry transgene to chromosome 3 and confirmed this location by fluorescence in situ hybridization (FISH) of the Sry construct to metaphase chromosomes. Using quantitative PCR, we estimate that 12-14 copies of the transgene were inserted. The anogenital distance (AGD) of FCG pups at 27-29 days after birth was not different in XX vs. XY males, or XX vs. XY females, suggesting that differences between XX and XY mice with the same type of gonad are not caused by difference in prenatal androgen levels. CONCLUSION The Sry transgene in FCG mice is present in multiple copies at one locus on chromosome 3, which does not interrupt known genes. XX and XY mice with the same type of gonad do not show evidence of different androgen levels prenatally.
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Affiliation(s)
- Yuichiro Itoh
- />Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, 610 Charles E. Young Drive South, Los Angeles, CA USA
| | - Ryan Mackie
- />Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, 610 Charles E. Young Drive South, Los Angeles, CA USA
| | - Kathy Kampf
- />Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, 610 Charles E. Young Drive South, Los Angeles, CA USA
| | - Shelly Domadia
- />Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, 610 Charles E. Young Drive South, Los Angeles, CA USA
| | - Judith D Brown
- />Institute for Systems Genomics and the Department of Allied Health Sciences, University of CT, Storrs, CT USA
| | - Rachel O’Neill
- />Institute for Systems Genomics and the Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT USA
| | - Arthur P Arnold
- />Department of Integrative Biology & Physiology, and Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, 610 Charles E. Young Drive South, Los Angeles, CA USA
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Stocks M, Dean R, Rogell B, Friberg U. Sex-specific trans-regulatory variation on the Drosophila melanogaster X chromosome. PLoS Genet 2015; 11:e1005015. [PMID: 25679222 PMCID: PMC4334168 DOI: 10.1371/journal.pgen.1005015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 01/22/2015] [Indexed: 11/19/2022] Open
Abstract
The X chromosome constitutes a unique genomic environment because it is present in one copy in males, but two copies in females. This simple fact has motivated several theoretical predictions with respect to how standing genetic variation on the X chromosome should differ from the autosomes. Unmasked expression of deleterious mutations in males and a lower census size are expected to reduce variation, while allelic variants with sexually antagonistic effects, and potentially those with a sex-specific effect, could accumulate on the X chromosome and contribute to increased genetic variation. In addition, incomplete dosage compensation of the X chromosome could potentially dampen the male-specific effects of random mutations, and promote the accumulation of X-linked alleles with sexually dimorphic phenotypic effects. Here we test both the amount and the type of genetic variation on the X chromosome within a population of Drosophila melanogaster, by comparing the proportion of X linked and autosomal trans-regulatory SNPs with a sexually concordant and discordant effect on gene expression. We find that the X chromosome is depleted for SNPs with a sexually concordant effect, but hosts comparatively more SNPs with a sexually discordant effect. Interestingly, the contrasting results for SNPs with sexually concordant and discordant effects are driven by SNPs with a larger influence on expression in females than expression in males. Furthermore, the distribution of these SNPs is shifted towards regions where dosage compensation is predicted to be less complete. These results suggest that intrinsic properties of dosage compensation influence either the accumulation of different types of trans-factors and/or their propensity to accumulate mutations. Our findings document a potential mechanistic basis for sex-specific genetic variation, and identify the X as a reservoir for sexually dimorphic phenotypic variation. These results have general implications for X chromosome evolution, as well as the genetic basis of sex-specific evolutionary change.
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Affiliation(s)
- Michael Stocks
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
- Department of Plant Ecology and Evolution, Uppsala University, Uppsala, Sweden
| | - Rebecca Dean
- Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
- * E-mail: (RD); (UF)
| | - Björn Rogell
- Department of Animal Ecology, Uppsala University, Uppsala, Sweden
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Urban Friberg
- Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden
- IFM Biology, AVIAN Behaviour and Genomics group, Linköping University, Linköping, Sweden
- * E-mail: (RD); (UF)
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Tagirov M, Rutkowska J. Sexual Dimorphism in the Early Embryogenesis in Zebra Finches. PLoS One 2014; 9:e114625. [PMID: 25493645 PMCID: PMC4262425 DOI: 10.1371/journal.pone.0114625] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 11/12/2014] [Indexed: 01/06/2023] Open
Abstract
Sex-specific gene expression before the onset of gonadogensis has been documented in embryos of mammals and chickens. In several mammalian species, differences in gene expression are accompanied by faster growth of pre-implantation male embryos. Here we asked whether avian embryos before gonadal differentiation are also sex-dimorphic in size and what genes regulate their growth. We used captive zebra finches (Taeniopygia guttata) whose freshly laid eggs were artificially incubated for 36–40 hours. Analyses controlling for the exact time of incubation of 81 embryos revealed that males were larger than females in terms of Hamburger and Hamilton stage and number of somites. Expression of 15 genes involved in cell cycle regulation, growth, metabolic activity, steroidogenic pathway and stress modulation were measured using RT-PCR in 5 male and 5 female embryos incubated for exactly 36 h. We found that in the presence of equal levels of the growth hormone itself, the faster growth of male embryos is most likely achieved by the overexpression of the growth hormone receptor gene and three other genes responsible for cell cycle regulation and metabolism, all of them located on the Z chromosome. Autosomal genes did not show sex-specific expression, except for the steroidogenic factor 1 which was expressed only in female embryos. To our knowledge this is the first report of sexual size dimorphism before gonadogenesis in birds. The finding suggests that faster growth of early male embryos is conserved through the mammalian and bird phyla, irrespective of their differential sex chromosome systems.
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Affiliation(s)
- Makhsud Tagirov
- Poultry Research Institute, Ukrainian Academy of Agrarian Sciences, Borky, Ukraine
| | - Joanna Rutkowska
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
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Condro MC, White SA. Distribution of language-related Cntnap2 protein in neural circuits critical for vocal learning. J Comp Neurol 2014; 522:169-85. [PMID: 23818387 DOI: 10.1002/cne.23394] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/11/2013] [Accepted: 06/19/2013] [Indexed: 11/12/2022]
Abstract
Variants of the contactin associated protein-like 2 (Cntnap2) gene are risk factors for language-related disorders including autism spectrum disorder, specific language impairment, and stuttering. Songbirds are useful models for study of human speech disorders due to their shared capacity for vocal learning, which relies on similar cortico-basal ganglia circuitry and genetic factors. Here we investigate Cntnap2 protein expression in the brain of the zebra finch, a songbird species in which males, but not females, learn their courtship songs. We hypothesize that Cntnap2 has overlapping functions in vocal learning species, and expect to find protein expression in song-related areas of the zebra finch brain. We further expect that the distribution of this membrane-bound protein may not completely mirror its mRNA distribution due to the distinct subcellular localization of the two molecular species. We find that Cntnap2 protein is enriched in several song control regions relative to surrounding tissues, particularly within the adult male, but not female, robust nucleus of the arcopallium (RA), a cortical song control region analogous to human layer 5 primary motor cortex. The onset of this sexually dimorphic expression coincides with the onset of sensorimotor learning in developing males. Enrichment in male RA appears due to expression in projection neurons within the nucleus, as well as to additional expression in nerve terminals of cortical projections to RA from the lateral magnocellular nucleus of the nidopallium. Cntnap2 protein expression in zebra finch brain supports the hypothesis that this molecule affects neural connectivity critical for vocal learning across taxonomic classes.
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Affiliation(s)
- Michael C Condro
- Molecular, Cellular & Integrative Physiology Interdepartmental Program, University of California, Los Angeles, California, 90095
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Scerbo MJ, Freire-Regatillo A, Cisternas CD, Brunotto M, Arevalo MA, Garcia-Segura LM, Cambiasso MJ. Neurogenin 3 mediates sex chromosome effects on the generation of sex differences in hypothalamic neuronal development. Front Cell Neurosci 2014; 8:188. [PMID: 25071448 PMCID: PMC4086225 DOI: 10.3389/fncel.2014.00188] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/19/2014] [Indexed: 01/01/2023] Open
Abstract
The organizational action of testosterone during critical periods of development is the cause of numerous sex differences in the brain. However, sex differences in neuritogenesis have been detected in primary neuronal hypothalamic cultures prepared before the peak of testosterone production by fetal testis. In the present study we assessed the hypothesis of that cell-autonomous action of sex chromosomes can differentially regulate the expression of the neuritogenic gene neurogenin 3 (Ngn3) in male and female hypothalamic neurons, generating sex differences in neuronal development. Neuronal cultures were prepared from male and female E14 mouse hypothalami, before the fetal peak of testosterone. Female neurons showed enhanced neuritogenesis and higher expression of Ngn3 than male neurons. The silencing of Ngn3 abolished sex differences in neuritogenesis, decreasing the differentiation of female neurons. The sex difference in Ngn3 expression was determined by sex chromosomes, as demonstrated using the four core genotypes mouse model, in which a spontaneous deletion of the testis-determining gene Sry from the Y chromosome was combined with the insertion of the Sry gene onto an autosome. In addition, the expression of Ngn3, which is also known to mediate the neuritogenic actions of estradiol, was increased in the cultures treated with the hormone, but only in those from male embryos. Furthermore, the hormone reversed the sex differences in neuritogenesis promoting the differentiation of male neurons. These findings indicate that Ngn3 mediates both cell-autonomous actions of sex chromosomes and hormonal effects on neuritogenesis.
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Affiliation(s)
- María J Scerbo
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET - Universidad Nacional de Córdoba Córdoba, Argentina
| | | | - Carla D Cisternas
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET - Universidad Nacional de Córdoba Córdoba, Argentina ; Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba Córdoba, Argentina
| | - Mabel Brunotto
- Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba Córdoba, Argentina
| | - Maria A Arevalo
- Instituto Cajal, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | | | - María J Cambiasso
- Laboratory of Neurophysiology, Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET - Universidad Nacional de Córdoba Córdoba, Argentina ; Departamento de Biología Bucal, Facultad de Odontología - Universidad Nacional de Córdoba Córdoba, Argentina
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44
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Joel D, Yankelevitch-Yahav R. Reconceptualizing sex, brain and psychopathology: interaction, interaction, interaction. Br J Pharmacol 2014; 171:4620-35. [PMID: 24758640 DOI: 10.1111/bph.12732] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 03/22/2014] [Accepted: 03/26/2014] [Indexed: 01/08/2023] Open
Abstract
In recent years there has been a growing recognition of the influence of sex on brain structure and function, and in relation, on the susceptibility, prevalence and response to treatment of psychiatric disorders. Most theories and descriptions of the effects of sex on the brain are dominated by an analogy to the current interpretation of the effects of sex on the reproductive system, according to which sex is a divergence system that exerts a unitary, overriding and serial effect on the form of other systems. We shortly summarize different lines of evidence that contradict aspects of this analogy. The new view that emerges from these data is of sex as a complex system whose different components interact with one another and with other systems to affect body and brain. The paradigm shift that this understanding calls for is from thinking of sex in terms of sexual dimorphism and sex differences, to thinking of sex in terms of its interactions with other factors and processes. Our review of data obtained from animal models of psychopathology clearly reveals the need for such a paradigmatic shift, because in the field of animal behaviour whether a sex difference exists and its direction depend on the interaction of many factors including, species, strain, age, specific test employed and a multitude of environmental factors. We conclude by explaining how the new conceptualization can account for sex differences in psychopathology.
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Affiliation(s)
- D Joel
- School of Psychological Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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Li J, Chen X, McClusky R, Ruiz-Sundstrom M, Itoh Y, Umar S, Arnold AP, Eghbali M. The number of X chromosomes influences protection from cardiac ischaemia/reperfusion injury in mice: one X is better than two. Cardiovasc Res 2014; 102:375-84. [PMID: 24654234 DOI: 10.1093/cvr/cvu064] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIM Sex differences in coronary heart disease have been attributed to sex hormones, whereas the potential role of the sex chromosomes has been ignored so far. Here, we investigated the role of the sex chromosomes in causing sex differences in myocardial ischaemia/reperfusion (I/R) injury. METHODS AND RESULTS We used two unique mouse models, the 'four core genotypes' [XX mice with ovaries (XXF) or testes (XXM) and XY mice with ovaries (XYF) or testes (XYM)] and XY* (gonadal male or female mice with one or two X chromosomes). All mice were gonadectomized (GDX). In vivo or isolated Langendorff-perfused hearts were subjected to I/R injury. The in vivo infarct size in XY mice was significantly smaller than XX mice regardless of their gonadal type (24.5 ± 4.1% in XYF and 21.8 ± 3.3% in XYM vs. 37.0 ± 3.2% in XXF and 35.5 ± 2.1% in XXM, P < 0.01). Consistent with the results in vivo, the infarct size was markedly smaller and cardiac functional recovery was significantly better in XY mice compared with XX ex vivo. The mitochondrial calcium retention capacity was significantly higher in XY compared with XX mice (nmol/mg protein: XXF = 126 ± 9 and XXM = 192 ± 45 vs. XYF = 250 ± 56 and XYM = 286 ± 51, P < 0.05). In XY* mice, mice with 2X chromosomes had larger infarct size (2X females = 41.4 ± 8.9% and 2X males = 46.3 ± 9.5% vs. 1X females = 23.7 ± 3.9% and 1X males = 26.6 ± 6.9%, P < 0.05) and lower heart functional recovery, compared with those with 1X chromosome. Several X genes that escape X inactivation (Eif2s3x, Kdm6a, and Kdm5c) showed higher expression in XX than in XY hearts. CONCLUSION XX mice have higher vulnerability to I/R injury compared with XY mice, which is due to the number of X chromosomes rather than the absence of the Y chromosome.
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Affiliation(s)
- Jingyuan Li
- Department of Anesthesiology, Division of Molecular Medicine, David Geffen School of Medicine at University of California Los Angeles, BH-160CHS, Los Angeles, CA 90095-7115, USA
| | - Xuqi Chen
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Rebecca McClusky
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Maureen Ruiz-Sundstrom
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yuichiro Itoh
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Soban Umar
- Department of Anesthesiology, Division of Molecular Medicine, David Geffen School of Medicine at University of California Los Angeles, BH-160CHS, Los Angeles, CA 90095-7115, USA
| | - Arthur P Arnold
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Mansoureh Eghbali
- Department of Anesthesiology, Division of Molecular Medicine, David Geffen School of Medicine at University of California Los Angeles, BH-160CHS, Los Angeles, CA 90095-7115, USA Cardiovascular Research Laboratories, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
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Renfree MB, Chew KY, Shaw G. Hormone-independent pathways of sexual differentiation. Sex Dev 2014; 8:327-36. [PMID: 24577198 DOI: 10.1159/000358447] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
New observations over the last 25 years of hormone-independent sexual dimorphisms have gradually and unequivocally overturned the dogma, arising from Jost's elegant experiments in the mid-1900s, that all somatic sex dimorphisms in vertebrates arise from the action of gonadal hormones. Although we know that Sry, a Y-linked gene, is the primary gonadal sex determinant in mammals, more recent analysis in marsupials, mice, and finches has highlighted numerous sexual dimorphisms that are evident well before the differentiation of the testis and which cannot be explained by a sexually dimorphic hormonal environment. In marsupials, scrotal bulges and mammary primordia are visible before the testis has differentiated due to the expression of a gene(s) on the X chromosome. ZZ and ZW gynandromorph finches have brains that develop in a sexually dimorphic way dependent on their sex chromosome content. In genetically manipulated mice, it is the X chromosomes, not the gonads, that determine many characters including rate of early development, adiposity, and neural circuits. Even spotted hyenas have sexual dimorphisms that cannot be simply explained by hormonal exposure. This review discusses the recent findings that confirm that there are hormone-independent sexual dimorphisms well before the gonads begin to produce their hormones.
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Affiliation(s)
- Marilyn B Renfree
- Department of Zoology, The University of Melbourne, Melbourne, Vic., Australia
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XY sex chromosome complement, compared with XX, in the CNS confers greater neurodegeneration during experimental autoimmune encephalomyelitis. Proc Natl Acad Sci U S A 2014; 111:2806-11. [PMID: 24550311 DOI: 10.1073/pnas.1307091111] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Women are more susceptible to multiple sclerosis (MS) and have more robust immune responses than men. However, men with MS tend to demonstrate a more progressive disease course than women, suggesting a disconnect between the severity of an immune attack and the CNS response to a given immune attack. We have previously shown in an MS model, experimental autoimmune encephalomyelitis, that autoantigen-sensitized XX lymph node cells, compared with XY, are more encephalitogenic. These studies demonstrated an effect of sex chromosomes in the induction of immune responses, but did not address a potential role of sex chromosomes in the CNS response to immune-mediated injury. Here, we examined this possibility using XX versus XY bone marrow chimeras reconstituted with a common immune system of one sex chromosomal type. We found that experimental autoimmune encephalomyelitis mice with an XY sex chromosome complement in the CNS, compared with XX, demonstrated greater clinical disease severity with more neuropathology in the spinal cord, cerebellum, and cerebral cortex. A candidate gene on the X chromosome, toll-like receptor 7, was then examined. Toll-like receptor 7 expression in cortical neurons was higher in mice with XY compared with mice with XX CNS, consistent with the known neurodegenerative role for toll-like receptor 7 in neurons. These results suggest that sex chromosome effects on neurodegeneration in the CNS run counter to effects on immune responses, and may bear relevance to the clinical enigma of greater MS susceptibility in women but faster disability progression in men. This is a demonstration of a direct effect of sex chromosome complement on neurodegeneration in a neurological disease.
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Maehiro S, Takeuchi A, Yamashita J, Hiraki T, Kawabata Y, Nakasone K, Hosono K, Usami T, Paul-Prasanth B, Nagahama Y, Oka Y, Okubo K. Sexually dimorphic expression of the sex chromosome-linked genes cntfa and pdlim3a in the medaka brain. Biochem Biophys Res Commun 2014; 445:113-9. [DOI: 10.1016/j.bbrc.2014.01.131] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 01/25/2014] [Indexed: 10/25/2022]
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50
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The variety of vertebrate mechanisms of sex determination. BIOMED RESEARCH INTERNATIONAL 2013; 2013:587460. [PMID: 24369014 PMCID: PMC3867867 DOI: 10.1155/2013/587460] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 09/26/2013] [Accepted: 10/28/2013] [Indexed: 12/23/2022]
Abstract
The review deals with features of sex determination in vertebrates. The mechanisms of sex determination are compared between fishes, amphibians, reptilians, birds, and mammals. We focus on structural and functional differences in the role of sex-determining genes in different vertebrates. Special attention is paid to the role of estrogens in sex determination in nonmammalian vertebrates.
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