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Haque R, Kurien SP, Setty H, Salzberg Y, Stelzer G, Litvak E, Gingold H, Rechavi O, Oren-Suissa M. Sex-specific developmental gene expression atlas unveils dimorphic gene networks in C. elegans. Nat Commun 2024; 15:4273. [PMID: 38769103 PMCID: PMC11106331 DOI: 10.1038/s41467-024-48369-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 04/24/2024] [Indexed: 05/22/2024] Open
Abstract
Sex-specific traits and behaviors emerge during development by the acquisition of unique properties in the nervous system of each sex. However, the genetic events responsible for introducing these sex-specific features remain poorly understood. In this study, we create a comprehensive gene expression atlas of pure populations of hermaphrodites and males of the nematode Caenorhabditis elegans across development. We discover numerous differentially expressed genes, including neuronal gene families like transcription factors, neuropeptides, and G protein-coupled receptors. We identify INS-39, an insulin-like peptide, as a prominent male-biased gene expressed specifically in ciliated sensory neurons. We show that INS-39 serves as an early-stage male marker, facilitating the effective isolation of males in high-throughput experiments. Through complex and sex-specific regulation, ins-39 plays pleiotropic sexually dimorphic roles in various behaviors, while also playing a shared, dimorphic role in early life stress. This study offers a comparative sexual and developmental gene expression database for C. elegans. Furthermore, it highlights conserved genes that may underlie the sexually dimorphic manifestation of different human diseases.
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Affiliation(s)
- Rizwanul Haque
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Sonu Peedikayil Kurien
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Hagar Setty
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Yehuda Salzberg
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
| | - Gil Stelzer
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Einav Litvak
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Hila Gingold
- Department of Neurobiology, Wise Faculty of Life Sciences & Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Oded Rechavi
- Department of Neurobiology, Wise Faculty of Life Sciences & Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Meital Oren-Suissa
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
- Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel.
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Jackson LR, Lopez MS, Alward B. Breaking Through the Bottleneck: Krogh's Principle in Behavioral Neuroendocrinology and the Potential of Gene Editing. Integr Comp Biol 2023; 63:428-443. [PMID: 37312279 PMCID: PMC10445420 DOI: 10.1093/icb/icad068] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 06/15/2023] Open
Abstract
In 1929, August Krogh wrote that for every question in biology, there is a species or collection of species in which pursuing such questions is the most appropriate for achieving the deepest insights. Referred to as "Krogh's Principle," these words are a guiding force for many biologists. In practice, Krogh's principle might guide a biologist interested in studying bi-parental care to choose not to use lab mice, in which the female does most of the parenting, but instead study species in which bi-parental care is present and clearly observable, such as in certain poison dart frogs. This approach to pursuing biological questions has been fruitful, with more in-depth insights achievable with new technologies. However, up until recently, an important limitation of Krogh's principle for biologists interested in the functions of certain genes, was certain techniques were only available for a few traditional model organisms such as lab mice, fruit flies (Drosophila melanogaster), zebrafish (Danio rerio) and C. elegans (Caenorhabditis elegans), in which testing the functions of molecular systems on biological processes can be achieved using genetic knockout (KO) and transgenic technology. These methods are typically more precise than other approaches (e.g., pharmacology) commonly used in nontraditional model organisms to address similar questions. Therefore, some of the most in-depth insights into our understanding of the molecular control of these mechanisms have come from a small number of genetically tractable species. Recent advances in gene editing technology such as CRISPR (Clustered Regularly Interspersed Short Palindromic Repeats)/Cas9 gene editing as a laboratory tool has changed the insights achievable for biologists applying Krogh's principle. In this review, we will provide a brief summary on how some researchers of nontraditional model organisms have been able to achieve different levels of experimental precision with limited genetic tractability in their non-traditional model organism in the field of behavioral neuroendocrinology, a field in which understanding tissue and brain-region specific actions of molecules of interest has been a major goal. Then, we will highlight the exciting potential of Krogh's principle using discoveries made in a popular model species of social behavior, the African cichlid fish Astatotilapia burtoni. Specifically, we will focus on insights gained from studies of the control of social status by sex steroid hormones (androgens and estrogens) in A. burtoni that originated during field observations during the 1970s, and have recently culminated in novel insights from CRISPR/Cas9 gene editing in laboratory studies. Our review highlighting discoveries in A. burtoni may function as a roadmap for others using Krogh's principle aiming to incorporate gene editing into their research program. Gene editing is thus a powerful complimentary laboratory tool researchers can use to yield novel insights into understanding the molecular mechanisms of physiology and behavior in non-traditional model organisms.
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Affiliation(s)
- Lillian R Jackson
- Department of Psychology, University of Houston, Houston, TX 77204USA
| | - Mariana S Lopez
- Department of Psychology, University of Houston, Houston, TX 77204USA
| | - Beau Alward
- Department of Psychology, University of Houston, Houston, TX 77204USA
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77004USA
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Dai X, Pradhan A, Liu J, Liu R, Zhai G, Zhou L, Dai J, Shao F, Yuan Z, Wang Z, Yin Z. Zebrafish gonad mutant models reveal neuroendocrine mechanisms of brain sexual dimorphism and male mating behaviors of different brain regions. Biol Sex Differ 2023; 14:53. [PMID: 37605245 PMCID: PMC10440941 DOI: 10.1186/s13293-023-00534-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/16/2023] [Indexed: 08/23/2023] Open
Abstract
BACKGROUND Sexually dimorphic mating behaviors differ between sexes and involve gonadal hormones and possibly sexually dimorphic gene expression in the brain. However, the associations among the brain, gonad, and sexual behavior in teleosts are still unclear. Here, we utilized germ cells-free tdrd12 knockout (KO) zebrafish, and steroid synthesis enzyme cyp17a1-deficient zebrafish to investigate the differences and interplays in the brain-gonad-behavior axis, and the molecular control of brain dimorphism and male mating behaviors. METHODS Tdrd12+/-; cyp17a1+/- double heterozygous parents were crossed to obtain tdrd12-/-; cyp17a1+/+ (tdrd12 KO), tdrd12+/+; cyp17a1-/- (cyp17a1 KO), and tdrd12-/-; cyp17a1-/- (double KO) homozygous progenies. Comparative analysis of mating behaviors were evaluated using Viewpoint zebrafish tracking software and sexual traits were thoroughly characterized based on anatomical and histological experiments in these KOs and wild types. The steroid hormone levels (testosterone, 11-ketotestosterone and 17β-estradiol) in the brains, gonads, and serum were measured using ELISA kits. To achieve a higher resolution view of the differences in region-specific expression patterns of the brain, the brains of these KOs, and control male and female fish were dissected into three regions: the forebrain, midbrain, and hindbrain for transcriptomic analysis. RESULTS Qualitative analysis of mating behaviors demonstrated that tdrd12-/- fish behaved in the same manner as wild-type males to trigger oviposition behavior, while cyp17a1-/- and double knockout (KO) fish did not exhibit these behaviors. Based on the observation of sex characteristics, mating behaviors and hormone levels in these mutants, we found that the maintenance of secondary sex characteristics and male mating behavior did not depend on the presence of germ cells; rather, they depended mainly on the 11-ketotestosterone and testosterone levels secreted into the brain-gonad regulatory axis. RNA-seq analysis of different brain regions revealed that the brain transcript profile of tdrd12-/- fish was similar to that of wild-type males, especially in the forebrain and midbrain. However, the brain transcript profiles of cyp17a1-/- and double KO fish were distinct from those of wild-type males and were partially biased towards the expression pattern of the female brain. Our results revealed important candidate genes and signaling pathways, such as synaptic signaling/neurotransmission, MAPK signaling, and steroid hormone pathways, that shape brain dimorphism and modulate male mating behavior in zebrafish. CONCLUSIONS Our results provide comprehensive analyses and new insights regarding the endogenous interactions in the brain-gonad-behavior axis. Moreover, this study revealed the crucial candidate genes and neural signaling pathways of different brain regions that are involved in modulating brain dimorphism and male mating behavior in zebrafish, which would significantly light up the understanding the neuroendocrine and molecular mechanisms modulating brain dimorphism and male mating behavior in zebrafish and other teleost fish.
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Affiliation(s)
- Xiangyan Dai
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Ajay Pradhan
- Biology, The Life Science Center, School of Science and Technology, Örebrorebro University, 70182, Örebro, Sweden
| | - Jiao Liu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Ruolan Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Gang Zhai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Linyan Zhou
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Jiyan Dai
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Feng Shao
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Zhiyong Yuan
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, 400715, China
| | - Zhijian Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing, 400715, China.
| | - Zhan Yin
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
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Liu X, Feng X, Huang H, Huang K, Xu Y, Ye S, Tseng YT, Wei P, Wang L, Wang F. Male and female mice display consistent lifelong ability to address potential life-threatening cues using different post-threat coping strategies. BMC Biol 2022; 20:281. [PMID: 36522765 PMCID: PMC9753375 DOI: 10.1186/s12915-022-01486-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Sex differences ranging from physiological functions to pathological disorders are developmentally hard-wired in a broad range of animals, from invertebrates to humans. These differences ensure that animals can display appropriate behaviors under a variety of circumstances, such as aggression, hunting, sleep, mating, and parental care, which are often thought to be important in the acquisition of resources, including territory, food, and mates. Although there are reports of an absence of sexual dimorphism in the context of innate fear, the question of whether there is sexual dimorphism of innate defensive behavior is still an open question. Therefore, an in-depth investigation to determine whether there are sex differences in developmentally hard-wired innate defensive behaviors in life-threatening circumstances is warranted. RESULTS We found that innate defensive behavioral responses to potentially life-threatening stimuli between males and females were indistinguishable over their lifespan. However, by using 3 dimensional (3D)-motion learning framework analysis, we found that males and females showed different behavioral patterns after escaping to the refuge. Specifically, the defensive "freezing" occurred primarily in males, whereas females were more likely to return directly to exploration. Moreover, there were also no estrous phase differences in innate defensive behavioral responses after looming stimuli. CONCLUSIONS Our results demonstrate that visually-evoked innate fear behavior is highly conserved throughout the lifespan in both males and females, while specific post-threat coping strategies depend on sex. These findings indicate that innate fear behavior is essential to both sexes and as such, there are no evolutionary-driven sex differences in defensive ability.
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Affiliation(s)
- Xue Liu
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaolong Feng
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
| | - Hongren Huang
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kang Huang
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
| | - Yang Xu
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuwei Ye
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
| | - Yu-Ting Tseng
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
| | - Pengfei Wei
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
| | - Liping Wang
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China
| | - Feng Wang
- Shenzhen Key Lab of Translational Research for Brain Diseases, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.
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5
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Abstract
The role of central estrogen in cognitive, metabolic, and reproductive health has long fascinated the lay public and scientists alike. In the last two decades, insight into estrogen signaling in the brain and its impact on female physiology is beginning to catch up with the vast information already established for its actions on peripheral tissues. Using newer methods to manipulate estrogen signaling in hormone-sensitive brain regions, neuroscientists are now identifying the molecular pathways and neuronal subtypes required for controlling sex-dependent energy allocation. However, the immense cellular complexity of these hormone-sensitive brain regions makes it clear that more research is needed to fully appreciate how estrogen modulates neural circuits to regulate physiological and behavioral end points. Such insight is essential for understanding how natural or drug-induced hormone fluctuations across lifespan affect women's health.
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Affiliation(s)
- Holly A Ingraham
- Department of Cellular and Molecular Pharmacology, School of Medicine, Mission Bay, University of California, San Francisco, California, USA;
| | - Candice B Herber
- Department of Cellular and Molecular Pharmacology, School of Medicine, Mission Bay, University of California, San Francisco, California, USA;
| | - William C Krause
- Department of Cellular and Molecular Pharmacology, School of Medicine, Mission Bay, University of California, San Francisco, California, USA;
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Tanaka K, Besson V, Rivagorda M, Oury F, Marazzi G, Sassoon DA. Paternally expressed gene 3 (Pw1/Peg3) promotes sexual dimorphism in metabolism and behavior. PLoS Genet 2022; 18:e1010003. [PMID: 35025875 PMCID: PMC8791484 DOI: 10.1371/journal.pgen.1010003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 01/26/2022] [Accepted: 12/20/2021] [Indexed: 01/06/2023] Open
Abstract
The paternally expressed gene 3 (Pw1/Peg3) is a mammalian-specific parentally imprinted gene expressed in stem/progenitor cells of the brain and endocrine tissues. Here, we compared phenotypic characteristics in Pw1/Peg3 deficient male and female mice. Our findings indicate that Pw1/Peg3 is a key player for the determination of sexual dimorphism in metabolism and behavior. Mice carrying a paternally inherited Pw1/Peg3 mutant allele manifested postnatal deficits in GH/IGF dependent growth before weaning, sex steroid dependent masculinization during puberty, and insulin dependent fat accumulation in adulthood. As a result, Pw1/Peg3 deficient mice develop a sex-dependent global shift of body metabolism towards accelerated adiposity, diabetic-like insulin resistance, and fatty liver. Furthermore, Pw1/Peg3 deficient males displayed reduced social dominance and competitiveness concomitant with alterations in the vasopressinergic architecture in the brain. This study demonstrates that Pw1/Peg3 provides an epigenetic context that promotes male-specific characteristics through sex steroid pathways during postnatal development. Pw1/Peg3 is under parental specific epigenetic regulation. We propose that Pw1/Peg3 confers a selective advantage in mammals by regulating sexual dimorphism. To address this question, we examined the consequences of Pw1/Peg3 loss of function in mice in an age- and sex-dependent context and found that Pw1/Peg3 mutants display reduced sexual dimorphism in growth, metabolism and behaviors. Our findings support the intralocus sexual conflict model of genomic imprinting where it contributes in sexual differentiation. Furthermore, our observations provide a unifying role of sex steroid signaling as a common property of Pw1/Peg3 expressing stem/progenitor cells and differentiated endocrine cells, both of which remain proliferative in response to gonadal hormones in adult life.
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Affiliation(s)
- Karo Tanaka
- Stem Cells and Regenerative Medicine, Institute of Cardiometabolism and Nutrition (ICAN), INSERM U1166, University of Pierre and Marie Curie Paris VI, Paris, France
| | - Vanessa Besson
- Stem Cells and Regenerative Medicine, Institute of Cardiometabolism and Nutrition (ICAN), INSERM U1166, University of Pierre and Marie Curie Paris VI, Paris, France
| | - Manon Rivagorda
- Hormonal Regulation of Brain Development and Functions, INSERM U1151, Institut Necker Enfants Malades, Paris, France
| | - Franck Oury
- Hormonal Regulation of Brain Development and Functions, INSERM U1151, Institut Necker Enfants Malades, Paris, France
| | - Giovanna Marazzi
- Stem Cells and Regenerative Medicine, Institute of Cardiometabolism and Nutrition (ICAN), INSERM U1166, University of Pierre and Marie Curie Paris VI, Paris, France
| | - David A. Sassoon
- Stem Cells and Regenerative Medicine, Institute of Cardiometabolism and Nutrition (ICAN), INSERM U1166, University of Pierre and Marie Curie Paris VI, Paris, France
- * E-mail:
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7
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Kasimatis KR, Sánchez-Ramírez S, Stevenson ZC. Sexual Dimorphism through the Lens of Genome Manipulation, Forward Genetics, and Spatiotemporal Sequencing. Genome Biol Evol 2021; 13:evaa243. [PMID: 33587127 PMCID: PMC7883666 DOI: 10.1093/gbe/evaa243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2020] [Indexed: 11/14/2022] Open
Abstract
Sexual reproduction often leads to selection that favors the evolution of sex-limited traits or sex-specific variation for shared traits. These sexual dimorphisms manifest due to sex-specific genetic architectures and sex-biased gene expression across development, yet the molecular mechanisms underlying these patterns are largely unknown. The first step is to understand how sexual dimorphisms arise across the genotype-phenotype-fitness map. The emergence of "4D genome technologies" allows for efficient, high-throughput, and cost-effective manipulation and observations of this process. Studies of sexual dimorphism will benefit from combining these technological advances (e.g., precision genome editing, inducible transgenic systems, and single-cell RNA sequencing) with clever experiments inspired by classic designs (e.g., bulked segregant analysis, experimental evolution, and pedigree tracing). This perspective poses a synthetic view of how manipulative approaches coupled with cutting-edge observational methods and evolutionary theory are poised to uncover the molecular genetic basis of sexual dimorphism with unprecedented resolution. We outline hypothesis-driven experimental paradigms for identifying genetic mechanisms of sexual dimorphism among tissues, across development, and over evolutionary time.
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Affiliation(s)
- Katja R Kasimatis
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, USA
| | | | - Zachary C Stevenson
- Institute of Ecology and Evolution, University of Oregon, Eugene, Oregon, USA
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8
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Meeh KL, Rickel CT, Sansano AJ, Shirangi TR. The development of sex differences in the nervous system and behavior of flies, worms, and rodents. Dev Biol 2021; 472:75-84. [PMID: 33484707 DOI: 10.1016/j.ydbio.2021.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 01/14/2023]
Abstract
Understanding how sex differences in innate animal behaviors arise has long fascinated biologists. As a general rule, the potential for sex differences in behavior is built by the developmental actions of sex-specific hormones or regulatory proteins that direct the sexual differentiation of the nervous system. In the last decade, studies in several animal systems have uncovered neural circuit mechanisms underlying discrete sexually dimorphic behaviors. Moreover, how certain hormones and regulatory proteins implement the sexual differentiation of these neural circuits has been illuminated in tremendous detail. Here, we discuss some of these mechanisms with three case-studies-mate recognition in flies, maturation of mating behavior in worms, and play-fighting behavior in young rodents. These studies illustrate general and unique developmental mechanisms to establish sex differences in neuroanatomy and behavior and highlight future challenges for the field.
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Affiliation(s)
- Kristen L Meeh
- Villanova University, Department of Biology, 800 Lancaster Ave, Villanova, PA, 19085, USA
| | - Clare T Rickel
- Villanova University, Department of Biology, 800 Lancaster Ave, Villanova, PA, 19085, USA
| | - Alexander J Sansano
- Villanova University, Department of Biology, 800 Lancaster Ave, Villanova, PA, 19085, USA
| | - Troy R Shirangi
- Villanova University, Department of Biology, 800 Lancaster Ave, Villanova, PA, 19085, USA.
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9
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Mamta SK, Sudhakumari C, Kagawa H, Dutta-Gupta A, Senthilkumaran B. Controlled release of sex steroids through osmotic pump alters brain GnRH1 and catecholaminergic system dimorphically in the catfish, Clarias gariepinus. Brain Res Bull 2020; 164:325-333. [PMID: 32860867 DOI: 10.1016/j.brainresbull.2020.08.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 08/15/2020] [Accepted: 08/19/2020] [Indexed: 10/23/2022]
Abstract
The present study aimed to evaluate osmotic pump-mediated controlled release of estrogen in males and androgen in females to analyze the impact on gonadotropin-releasing hormone (GnRH1), catecholamines (CAs) and other associated genes in the catfish, Clarias gariepinus. During pre-spawning phase, catfish were separately implanted osmotic pumps loaded with 17β-estradiol (E2) in males and 17α-methyltestosterone (MT) in females at a dose of 10 μg/100 μl or saline (100 μl) controls into both sexes to release for 21 days and all fishes were maintained as per the duration. Further, GnRH1 expression levels were analysed in the discrete regions of brain after E2 and MT treatments in male and female catfish, respectively using qPCR which revealed that GnRH1 expression was significantly higher in E2 treated male as compared to the control. On the other hand, GnRH1 expression was lower in MT treated female when compared to the control in the discrete regions of brain. In addition, certain brain and monoaminergic system related genes showed a differential response. Catfish GnRH1 could be localized in preoptic area-hypothalamus (POA-HYP) that correlated with the expression profile in the discrete regions of catfish brain. Serum levels of sex steroids in the treated male fish indicated that the treatment of E2 could maintain and impart feminization effect even in the presence of endogenous androgen during gonadal recrudescence while such an effect was not seen in females with androgen treatment. Measurement of CAs, L-3,4-dihydroxyphenylalanine, dopamine and norepinephrine levels in the male and female brain after the controlled release of E2 and MT, respectively confirmed the modulation of neurotransmitters in the E2treated male than MT treated female fish. These results collectively suggest the severity of estrogenic over androgenic compounds to alter reproductive status even at a minimal dose by targeting CAs and GnRH1 at the level of brain of catfish. This study provides insights into the reproductive toxicity of sex steroid analogues at the level of brain GnRH1 and CA-ergic system in addition to serum T, 11-KT and E2 levels during gonadal recrudescence, which is a crucial period of gametogenesis preceding spawning.
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Affiliation(s)
- Sajwan-Khatri Mamta
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500046, Telangana, India
| | - Chenichery Sudhakumari
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500046, Telangana, India
| | - Hirohiko Kagawa
- Department of Marine Biology and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan
| | - Aparna Dutta-Gupta
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500046, Telangana, India
| | - Balasubramanian Senthilkumaran
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad, 500046, Telangana, India.
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Lee SLJ, Horsfield JA, Black MA, Rutherford K, Gemmell NJ. Identification of sex differences in zebrafish (Danio rerio) brains during early sexual differentiation and masculinization using 17α-methyltestoterone. Biol Reprod 2019; 99:446-460. [PMID: 29272338 DOI: 10.1093/biolre/iox175] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/18/2017] [Indexed: 12/26/2022] Open
Abstract
Sexual behavior in teleost fish is highly plastic. It can be attributed to the relatively few sex differences found in adult brain transcriptomes. Environmental and hormonal factors can influence sex-specific behavior. Androgen treatment stimulates behavioral masculinization. Sex dimorphic gene expression in developing teleost brains and the molecular basis for androgen-induced behavioral masculinization are poorly understood. In this study, juvenile zebrafish (Danio rerio) were treated with 100 ng/L of 17 alpha-methyltestosterone (MT) during sexual development from 20 days post fertilization to 40 days and 60 days post fertilization. We compared brain gene expression patterns in MT-treated zebrafish with control males and females using RNA-Seq to shed light on the dynamic changes in brain gene expression during sexual development and how androgens affect brain gene expression leading to behavior masculinization. We found modest differences in gene expression between juvenile male and female zebrafish brains. Brain aromatase (cyp19a1b), prostaglandin 3a synthase (ptges3a), and prostaglandin reductase 1 (ptgr1) were among the genes with sexually dimorphic expression patterns. MT treatment significantly altered gene expression relative to both male and female brains. Fewer differences were found among MT-treated brains and male brains compared to female brains, particularly at 60 dpf. MT treatment upregulated the expression of hydroxysteroid 11-beta dehydrogenase 2 (hsd11b2), deiodinase, iodothyronine, type II (dio2), and gonadotrophin releasing hormones (GnRH) 2 and 3 (gnrh2 and gnrh3) suggesting local synthesis of 11-ketotestosterone, triiodothyronine, and GnRHs in zebrafish brains which are influenced by androgens. Androgen, estrogen, prostaglandin, thyroid hormone, and GnRH signaling pathways likely interact to modulate teleost sexual behavior.
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Affiliation(s)
- Stephanie L J Lee
- Department of Anatomy, University of Otago, Dunedin, Otago, New Zealand
| | - Julia A Horsfield
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, Otago, New Zealand
| | - Michael A Black
- Department of Biochemistry, University of Otago, Dunedin, Otago, New Zealand
| | - Kim Rutherford
- Department of Anatomy, University of Otago, Dunedin, Otago, New Zealand
| | - Neil J Gemmell
- Department of Anatomy, University of Otago, Dunedin, Otago, New Zealand
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11
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Tosetti V, Sassone J, Ferri ALM, Taiana M, Bedini G, Nava S, Brenna G, Di Resta C, Pareyson D, Di Giulio AM, Carelli S, Parati EA, Gorio A. Transcriptional role of androgen receptor in the expression of long non-coding RNA Sox2OT in neurogenesis. PLoS One 2017; 12:e0180579. [PMID: 28704421 PMCID: PMC5507538 DOI: 10.1371/journal.pone.0180579] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 06/16/2017] [Indexed: 11/19/2022] Open
Abstract
The complex architecture of adult brain derives from tightly regulated migration and differentiation of precursor cells generated during embryonic neurogenesis. Changes at transcriptional level of genes that regulate migration and differentiation may lead to neurodevelopmental disorders. Androgen receptor (AR) is a transcription factor that is already expressed during early embryonic days. However, AR role in the regulation of gene expression at early embryonic stage is yet to be determinate. Long non-coding RNA (lncRNA) Sox2 overlapping transcript (Sox2OT) plays a crucial role in gene expression control during development but its transcriptional regulation is still to be clearly defined. Here, using Bicalutamide in order to pharmacologically inactivated AR, we investigated whether AR participates in the regulation of the transcription of the lncRNASox2OTat early embryonic stage. We identified a new DNA binding region upstream of Sox2 locus containing three androgen response elements (ARE), and found that AR binds such a sequence in embryonic neural stem cells and in mouse embryonic brain. Our data suggest that through this binding, AR can promote the RNA polymerase II dependent transcription of Sox2OT. Our findings also suggest that AR participates in embryonic neurogenesis through transcriptional control of the long non-coding RNA Sox2OT.
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Affiliation(s)
- Valentina Tosetti
- Department of Cerebrovascular Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
- Laboratory of Pharmacology, Department of Health Sciences, University of Milan, Milan, Italy
| | - Jenny Sassone
- Vita-Salute University and San Raffaele Scientific Institute, Division of Neuroscience, Milan, Italy
| | - Anna L. M. Ferri
- Department of Cerebrovascular Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Michela Taiana
- Clinic of Central and Peripheral Degenerative Neuropathies Unit, Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Gloria Bedini
- Department of Cerebrovascular Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Sara Nava
- Cell Therapy Production Unit, Laboratory of Cellular Neurobiology, Cerebrovascular Unit, and Unit of Molecular Neuro-Oncology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Greta Brenna
- Biostatistician Service Clinical Research—Scientific Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Chiara Di Resta
- Vita-Salute San Raffaele University, Milan, Italy
- Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Davide Pareyson
- Neurological Rare Diseases of Adulthood Unit, Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Anna Maria Di Giulio
- Laboratory of Pharmacology, Department of Health Sciences, University of Milan, Milan, Italy
- Pediatric Clinical Research Center Fondazione Romeo e Enrica Invernizzi, University of Milan, Milan, Italy
| | - Stephana Carelli
- Laboratory of Pharmacology, Department of Health Sciences, University of Milan, Milan, Italy
| | - Eugenio A. Parati
- Department of Cerebrovascular Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Alfredo Gorio
- Laboratory of Pharmacology, Department of Health Sciences, University of Milan, Milan, Italy
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12
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Bayless DW, Shah NM. Genetic dissection of neural circuits underlying sexually dimorphic social behaviours. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150109. [PMID: 26833830 DOI: 10.1098/rstb.2015.0109] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2015] [Indexed: 11/12/2022] Open
Abstract
The unique hormonal, genetic and epigenetic environments of males and females during development and adulthood shape the neural circuitry of the brain. These differences in neural circuitry result in sex-typical displays of social behaviours such as mating and aggression. Like other neural circuits, those underlying sex-typical social behaviours weave through complex brain regions that control a variety of diverse behaviours. For this reason, the functional dissection of neural circuits underlying sex-typical social behaviours has proved to be difficult. However, molecularly discrete neuronal subpopulations can be identified in the heterogeneous brain regions that control sex-typical social behaviours. In addition, the actions of oestrogens and androgens produce sex differences in gene expression within these brain regions, thereby highlighting the neuronal subpopulations most likely to control sexually dimorphic social behaviours. These conditions permit the implementation of innovative genetic approaches that, in mammals, are most highly advanced in the laboratory mouse. Such approaches have greatly advanced our understanding of the functional significance of sexually dimorphic neural circuits in the brain. In this review, we discuss the neural circuitry of sex-typical social behaviours in mice while highlighting the genetic technical innovations that have advanced the field.
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Affiliation(s)
- Daniel W Bayless
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94158, USA
| | - Nirao M Shah
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94158, USA
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13
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Pradhan A, Olsson PE. Zebrafish sexual behavior: role of sex steroid hormones and prostaglandins. Behav Brain Funct 2015; 11:23. [PMID: 26385780 PMCID: PMC4575480 DOI: 10.1186/s12993-015-0068-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 06/25/2015] [Indexed: 12/11/2022] Open
Abstract
Background Mating behavior differ between sexes and involves gonadal hormones and possibly sexually dimorphic gene expression in the brain. Sex steroids and prostaglandin E2 (PGE2) have been shown to regulate mammalian sexual behavior. The present study was aimed at determining whether exposure to sex steroids and prostaglandins could alter zebrafish sexual mating behavior. Methods Mating behavior and successful spawning was recorded following exposure to 17β-estradiol (E2), 11-ketotestosterone (11-KT), prostaglandin D2 (PGD2) and PGE2 via the water. qRT-PCR was used to analyze transcript levels in the forebrain, midbrain, and hindbrain of male and female zebrafish and compared to animals exposed to E2 via the water. Results Exposure of zebrafish to sex hormones resulted in alterations in behavior and spawning when male fish were exposed to E2 and female fish were exposed to 11-KT. Exposure to PGD2, and PGE2 did not alter mating behavior or spawning success. Determination of gene expression patterns of selected genes from three brain regions using qRT-PCR analysis demonstrated that the three brain regions differed in gene expression pattern and that there were differences between the sexes. In addition, E2 exposure also resulted in altered gene transcription profiles of several genes. Conclusions Exposure to sex hormones, but not prostaglandins altered mating behavior in zebrafish. The expression patterns of the studied genes indicate that there are large regional and gender-based differences in gene expression and that E2 treatment alter the gene expression pattern in all regions of the brain. Electronic supplementary material The online version of this article (doi:10.1186/s12993-015-0068-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ajay Pradhan
- Biology, The Life Science Center, School of Science and Technology, Örebro University, 701 82, Örebro, Sweden
| | - Per-Erik Olsson
- Biology, The Life Science Center, School of Science and Technology, Örebro University, 701 82, Örebro, Sweden.
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14
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Turning sex inside-out: Peripheral contributions to sexual differentiation of the central nervous system. Biol Sex Differ 2012; 3:12. [PMID: 22640590 PMCID: PMC3464926 DOI: 10.1186/2042-6410-3-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 05/28/2012] [Indexed: 02/04/2023] Open
Abstract
Sexual differentiation of the nervous system occurs via the interplay of genetics, endocrinology and social experience through development. Much of the research into mechanisms of sexual differentiation has been driven by an implicit theoretical framework in which these causal factors act primarily and directly on sexually dimorphic neural populations within the central nervous system. This review will examine an alternative explanation by describing what is known about the role of peripheral structures and mechanisms (both neural and non-neural) in producing sex differences in the central nervous system. The focus of the review will be on experimental evidence obtained from studies of androgenic masculinization of the spinal nucleus of the bulbocavernosus, but other systems will also be considered.
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15
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Meissner GW, Manoli DS, Chavez JF, Knapp JM, Lin TL, Stevens RJ, Mellert DJ, Tran DH, Baker BS. Functional dissection of the neural substrates for sexual behaviors in Drosophila melanogaster. Genetics 2011; 189:195-211. [PMID: 21705753 PMCID: PMC3176112 DOI: 10.1534/genetics.111.129940] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 06/13/2011] [Indexed: 11/18/2022] Open
Abstract
The male-specific Fruitless proteins (FruM) act to establish the potential for male courtship behavior in Drosophila melanogaster and are expressed in small groups of neurons throughout the nervous system. We screened ∼1000 GAL4 lines, using assays for general courtship, male-male interactions, and male fertility to determine the phenotypes resulting from the GAL4-driven inhibition of FruM expression in subsets of these neurons. A battery of secondary assays showed that the phenotypic classes of GAL4 lines could be divided into subgroups on the basis of additional neurobiological and behavioral criteria. For example, in some lines, restoration of FruM expression in cholinergic neurons restores fertility or reduces male-male courtship. Persistent chains of males courting each other in some lines results from males courting both sexes indiscriminately, whereas in other lines this phenotype results from apparent habituation deficits. Inhibition of ectopic FruM expression in females, in populations of neurons where FruM is necessary for male fertility, can rescue female infertility. To identify the neurons responsible for some of the observed behavioral alterations, we determined the overlap between the identified GAL4 lines and endogenous FruM expression in lines with fertility defects. The GAL4 lines causing fertility defects generally had widespread overlap with FruM expression in many regions of the nervous system, suggesting likely redundant FruM-expressing neuronal pathways capable of conferring male fertility. From associations between the screened behaviors, we propose a functional model for courtship initiation.
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Affiliation(s)
- Geoffrey W. Meissner
- Neurosciences Program, and
- Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, Virginia 20147
| | | | - Jose F. Chavez
- Department of Biology, Stanford University, Stanford, California 94305
| | - Jon-Michael Knapp
- Neurosciences Program, and
- Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, Virginia 20147
| | - Tasha L. Lin
- Department of Biology, Stanford University, Stanford, California 94305
| | - Robin J. Stevens
- Department of Biology, Stanford University, Stanford, California 94305
| | - David J. Mellert
- Department of Biology, Stanford University, Stanford, California 94305
- Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, Virginia 20147
| | - David H. Tran
- Department of Biology, Stanford University, Stanford, California 94305
| | - Bruce S. Baker
- Neurosciences Program, and
- Department of Biology, Stanford University, Stanford, California 94305
- Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, Virginia 20147
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16
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Abstract
In the twentieth century, the dominant model of sexual differentiation stated that genetic sex (XX versus XY) causes differentiation of the gonads, which then secrete gonadal hormones that act directly on tissues to induce sex differences in function. This serial model of sexual differentiation was simple, unifying and seductive. Recent evidence, however, indicates that the linear model is incorrect and that sex differences arise in response to diverse sex-specific signals originating from inherent differences in the genome and involve cellular mechanisms that are specific to individual tissues or brain regions. Moreover, sex-specific effects of the environment reciprocally affect biology, sometimes profoundly, and must therefore be integrated into a realistic model of sexual differentiation. A more appropriate model is a parallel-interactive model that encompasses the roles of multiple molecular signals and pathways that differentiate males and females, including synergistic and compensatory interactions among pathways and an important role for the environment.
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Affiliation(s)
- Margaret M McCarthy
- Departments of Physiology and Psychiatry and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA.
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17
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McCarthy MM. A lumpers versus splitters approach to sexual differentiation of the brain. Front Neuroendocrinol 2011; 32:114-23. [PMID: 21296103 PMCID: PMC3085725 DOI: 10.1016/j.yfrne.2011.01.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/22/2011] [Accepted: 01/31/2011] [Indexed: 12/17/2022]
Abstract
Over 50 years of rigorous empirical attention to the study of sexual differentiation of the brain has produced sufficient data to reveal fundamental guiding principles, but has also required the generation of new hypotheses to explain non-conforming observations. An early emphasis on the powerful impact and essential role of gonadal steroids is now complemented by an appreciation for genetic contributions to sex differences in the brain. The organizing effects of early steroid hormones on reproductively relevant brain regions and endpoints are largely dependent upon neuronal aromatization of androgens to estrogens. The effect of estradiol is mediated via estrogen receptors (ER). The presence or absence of ER can restrict hormone action to select cells and either prevent or invoke cell death. Alternatively, ER activation can initiate signaling cascades that induce cell-to-cell communication and thereby transduce organizational steroid effects to large numbers of cells. However, the specific details by which cell death and cell-to-cell communication are achieved appear to be locally, even cellularly, unique and specific to that particular subpopulation. As the field moves forward the increasingly specific and detailed elucidation of mechanism challenges us to generate new guiding principles in order to gain a holistic understanding of how the brain develops in males and females.
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Affiliation(s)
- Margaret M McCarthy
- Department of Physiology, University of Maryland School of Medicine, 655 West Baltimore St. Baltimore, MD 21201, USA.
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18
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19
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Wu MV, Shah NM. Control of masculinization of the brain and behavior. Curr Opin Neurobiol 2010; 21:116-23. [PMID: 20970320 DOI: 10.1016/j.conb.2010.09.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 09/27/2010] [Indexed: 02/05/2023]
Abstract
Sex steroid hormones exert a profound influence on the sexual differentiation and function of the neural circuits that mediate dimorphic behaviors. Both estrogen and testosterone are essential for male typical behaviors in many species. Recent studies with genetically modified mice provide important new insights into the logic whereby these two hormones coordinate the display of sexually dimorphic behaviors: estrogen sets up the masculine repertoire of sexual and territorial behaviors and testosterone controls the extent of these male displays.
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Affiliation(s)
- Melody V Wu
- Program in Neuroscience, University of California, San Francisco, MC2722, San Francisco, CA 94158, USA
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20
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Juntti SA, Tollkuhn J, Wu MV, Fraser EJ, Soderborg T, Tan S, Honda SI, Harada N, Shah NM. The androgen receptor governs the execution, but not programming, of male sexual and territorial behaviors. Neuron 2010; 66:260-72. [PMID: 20435002 DOI: 10.1016/j.neuron.2010.03.024] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2010] [Indexed: 11/25/2022]
Abstract
Testosterone and estrogen are essential for male behaviors in vertebrates. How these two signaling pathways interact to control masculinization of the brain and behavior remains to be established. Circulating testosterone activates the androgen receptor (AR) and also serves as the source of estrogen in the brain. We have used a genetic strategy to delete AR specifically in the mouse nervous system. This approach permits us to determine the function of AR in sexually dimorphic behaviors in males while maintaining circulating testosterone levels within the normal range. We find that AR mutant males exhibit masculine sexual and territorial displays, but they have striking deficits in specific components of these behaviors. Taken together with the surprisingly limited expression of AR in the developing brain, our findings indicate that testosterone acts as a precursor to estrogen to masculinize the brain and behavior, and signals via AR to control the levels of male behavioral displays.
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Affiliation(s)
- Scott A Juntti
- Graduate Program in Neuroscience, University of California, San Francisco, MC2722, San Francisco, CA 94158, USA
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21
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Yang JH, Baskin LS, DiSandro M. Gender Identity in Disorders of Sex Development: Review Article. Urology 2010; 75:153-9. [DOI: 10.1016/j.urology.2009.07.1286] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 06/29/2009] [Accepted: 07/03/2009] [Indexed: 10/20/2022]
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22
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Wu MV, Manoli DS, Fraser EJ, Coats JK, Tollkuhn J, Honda SI, Harada N, Shah NM. Estrogen masculinizes neural pathways and sex-specific behaviors. Cell 2009; 139:61-72. [PMID: 19804754 DOI: 10.1016/j.cell.2009.07.036] [Citation(s) in RCA: 295] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Revised: 05/18/2009] [Accepted: 07/10/2009] [Indexed: 10/20/2022]
Abstract
Sex hormones are essential for neural circuit development and sex-specific behaviors. Male behaviors require both testosterone and estrogen, but it is unclear how the two hormonal pathways intersect. Circulating testosterone activates the androgen receptor (AR) and is also converted into estrogen in the brain via aromatase. We demonstrate extensive sexual dimorphism in the number and projections of aromatase-expressing neurons. The masculinization of these cells is independent of AR but can be induced in females by either testosterone or estrogen, indicating a role for aromatase in sexual differentiation of these neurons. We provide evidence suggesting that aromatase is also important in activating male-specific aggression and urine marking because these behaviors can be elicited by testosterone in males mutant for AR and in females subjected to neonatal estrogen exposure. Our results suggest that aromatization of testosterone into estrogen is important for the development and activation of neural circuits that control male territorial behaviors.
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Affiliation(s)
- Melody V Wu
- Program in Neuroscience, University of California-San Francisco, San Francisco, CA 94158, USA
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23
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Wilson DA, Baker H, Brunjes P, Gilbertson TA, Hermer L, Hill DL, Matsunami H, Meredith M, Mistretta CM, Smeets MAM, Stowers L, Zhuang H. Chemoreception scientists gather under the Florida sun: The 31st Annual Association for Chemoreception Sciences meeting. Ann N Y Acad Sci 2009; 1170 Suppl 1:1-11. [PMID: 19712224 DOI: 10.1111/j.1749-6632.2009.05047.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 31st Annual Association for Chemoreception Sciences (AChemS) met in Sarasota, Florida April 22-26, 2009, attracting approximately 600 registrants and nearly 400 abstracts. In addition to poster and platform presentations, the program offered symposia, special lectures, and various National Institutes of Health (NIH)-sponsored workshops, including one on computational approaches to olfaction.
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Affiliation(s)
- Donald A Wilson
- Nathan Kline Institute and New York University School of Medicine, New York, USA.
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24
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Arnold AP. The organizational-activational hypothesis as the foundation for a unified theory of sexual differentiation of all mammalian tissues. Horm Behav 2009; 55:570-8. [PMID: 19446073 PMCID: PMC3671905 DOI: 10.1016/j.yhbeh.2009.03.011] [Citation(s) in RCA: 391] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 03/05/2009] [Accepted: 03/05/2009] [Indexed: 11/20/2022]
Abstract
The 1959 publication of the paper by Phoenix et al. was a major turning point in the study of sexual differentiation of the brain. That study showed that sex differences in behavior, and by extension in the brain, were permanently sexually differentiated by testosterone, a testicular secretion, during an early critical period of development. The study placed the brain together in a class with other major sexually dimorphic tissues (external genitalia and genital tracts), and proposed an integrated hormonal theory of sexual differentiation for all of these non-gonadal tissues. Since 1959, the organizational-activational theory has been amended but survives as a central concept that explains many sex differences in phenotype, in diverse tissues and at all levels of analysis from the molecular to the behavioral. In the last two decades, however, sex differences have been found that are not explained by such gonadal hormonal effects, but rather because of the primary action of genes encoded on the sex chromosomes. To integrate the classic organizational and activational effects with the more recently discovered sex chromosome effects, we propose a unified theory of sexual differentiation that applies to all mammalian tissues.
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Affiliation(s)
- Arthur P Arnold
- Department of Physiological Science, Laboratory of Neuroendocrinology of the Brain Research Institute, University of California, Los Angeles, Charles Young Drive South, Los Angeles CA 90095-1606, USA.
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25
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Jordan CL, DonCarlos L. Androgens in health and disease: an overview. Horm Behav 2008; 53:589-95. [PMID: 18407273 PMCID: PMC2676684 DOI: 10.1016/j.yhbeh.2008.02.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 02/15/2008] [Accepted: 02/15/2008] [Indexed: 11/26/2022]
Abstract
This special issue of Hormones and Behavior , “Androgens in health and disease: new insights into roles and mechanisms of action,” is prompted by a number of relatively recent findings that androgens affect brain morphology and function in ways not previously or widely appreciated. Moreover, recent results also make it clear that androgens utilize a variety of signaling molecules to exert their effects on the brain, which may or may not depend on the classic nuclear androgen receptor (AR). The papers in this issue underscore these two points. This overview is not intended as a comprehensive review of androgen action on the nervous system, since the papers in this issue serve that purpose, but rather to frame the basic issues and themes that tie these papers together. The sum effect of the stories told in this issue encourages us to broaden and refocus our view of androgen action on brain and behavior—to recognize that androgens affect many aspects of brain structure and function throughout the lifespan, from shaping its sexual phenotype to influencing its propensity for disease and repair, and that at least some of these actions are exerted via non-classical modes of action that in many cases were first identified in non-neural tissue or cells.
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Affiliation(s)
- Cynthia L. Jordan
- Neuroscience Program and Psychology Department, 108 Giltner Hall, Michigan State University, East Lansing, Michigan, 48824
| | - Lydia DonCarlos
- Department of Cell Biology, Neurobiology and Anatomy and Neuroscience Institute, 2160 S. First Avenue, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, 60153
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26
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The role of androgen receptors in the masculinization of brain and behavior: what we've learned from the testicular feminization mutation. Horm Behav 2008; 53:613-26. [PMID: 18374335 DOI: 10.1016/j.yhbeh.2008.01.013] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 01/24/2008] [Accepted: 01/28/2008] [Indexed: 11/26/2022]
Abstract
Many studies demonstrate that exposure to testicular steroids such as testosterone early in life masculinizes the developing brain, leading to permanent changes in behavior. Traditionally, masculinization of the rodent brain is believed to depend on estrogen receptors (ERs) and not androgen receptors (ARs). According to the aromatization hypothesis, circulating testosterone from the testes is converted locally in the brain by aromatase to estrogens, which then activate ERs to masculinize the brain. However, an emerging body of evidence indicates that the aromatization hypothesis cannot fully account for sex differences in brain morphology and behavior, and that androgens acting on ARs also play a role. The testicular feminization mutation (Tfm) in rodents, which produces a nonfunctional AR protein, provides an excellent model to probe the role of ARs in the development of brain and behavior. Tfm rodent models indicate that ARs are normally involved in the masculinization of many sexually dimorphic brain regions and a variety of behaviors, including sexual behaviors, stress response and cognitive processing. We review the role of ARs in the development of the brain and behavior, with an emphasis on what has been learned from Tfm rodents as well as from related mutations in humans causing complete androgen insensitivity.
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