1
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Graham GJ, Ibanez EM, Mitchell LJ, Weis KE, Raetzman LT, Cortesi F, Rhodes JS. Generation of the First Transgenic Line of the Iconic Coral Reef Fish Amphiprion ocellaris. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2024:10.1007/s10126-024-10357-1. [PMID: 39158665 DOI: 10.1007/s10126-024-10357-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2024] [Accepted: 08/07/2024] [Indexed: 08/20/2024]
Abstract
The common clownfish, Amphiprion ocellaris, is an iconic coral reef fish, ubiquitous in the marine aquarium hobby and useful for studying a variety of biological processes (e.g., mutual symbiosis, ultraviolet vision, and protandrous sex change). Recently, CRISPR/Cas9 methods were developed for knocking out specific genes for mechanistic studies. Here, we expand the genetic toolkit for A. ocellaris by creating the first transgenic line using the Tol2 transposon system. Fertilized eggs were co-injected with Tol2 transposase mRNA and a plasmid encoding an elongation factor-1α (Ef1α): green fluorescent protein (GFP) cassette at various concentrations, needle tip dimensions, and timepoints post-fertilization. We compared various injection parameters and sterilization methods to maximize the survival of injected eggs. F0s (n = 10) that were genotyped GFP + were then raised to 6 months of age and crossed with wild-type (WT) females to confirm germline transmission. F1 offspring were also raised and crossed in the same manner. The highly efficient Tol2 transposon system resulted in a 37% rate of transgenesis for surviving eggs amounting to a 2.7% yield of all injected eggs surviving and being GFP + (n = 160). Of these, 10 were raised to adulthood, 8 spawned, and 5/8 (62.5%) produced GFP + offspring. Further, two F1s crossed with WT females produced 54.2% and 44.6% GFP + offspring respectively, confirming the creation of a stable line. This is, to our knowledge, the first generation of a transgenic line in any coral reef fish. The ability to express transgenes of interest in the iconic anemonefish opens the door to a new era of exploration into their fascinating biology.
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Affiliation(s)
- Gabriel J Graham
- Department of Psychology, University of Illinois, Champaign, IL, 61820, USA
| | - Emma M Ibanez
- Department of Molecular & Cellular Biology, University of Illinois, Champaign, IL, USA
| | - Laurie J Mitchell
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, Onna Son, Okinawa, 904-0495, Japan
| | - Karen E Weis
- Department of Molecular & Integrative Physiology, University of Illinois, Champaign, IL, USA
| | - Lori T Raetzman
- Department of Molecular & Integrative Physiology, University of Illinois, Champaign, IL, USA
| | - Fabio Cortesi
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
- School of the Environment, The University of Queensland, Brisbane, QLD, Australia
| | - Justin S Rhodes
- Department of Psychology, University of Illinois, Champaign, IL, 61820, USA.
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2
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Parker CG, Gruenhagen GW, Hegarty BE, Histed AR, Streelman JT, Rhodes JS, Johnson ZV. Adult sex change leads to extensive forebrain reorganization in clownfish. Biol Sex Differ 2024; 15:58. [PMID: 39044232 PMCID: PMC11267845 DOI: 10.1186/s13293-024-00632-0] [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: 03/28/2024] [Accepted: 07/08/2024] [Indexed: 07/25/2024] Open
Abstract
BACKGROUND Sexual differentiation of the brain occurs in all major vertebrate lineages but is not well understood at a molecular and cellular level. Unlike most vertebrates, sex-changing fishes have the remarkable ability to change reproductive sex during adulthood in response to social stimuli, offering a unique opportunity to understand mechanisms by which the nervous system can initiate and coordinate sexual differentiation. METHODS This study explores sexual differentiation of the forebrain using single nucleus RNA-sequencing in the anemonefish Amphiprion ocellaris, producing the first cellular atlas of a sex-changing brain. RESULTS We uncover extensive sex differences in cell type-specific gene expression, relative proportions of cells, baseline neuronal excitation, and predicted inter-neuronal communication. Additionally, we identify the cholecystokinin, galanin, and estrogen systems as central molecular axes of sexual differentiation. Supported by these findings, we propose a model of sexual differentiation in the conserved vertebrate social decision-making network spanning multiple subtypes of neurons and glia, including neuronal subpopulations within the preoptic area that are positioned to regulate gonadal differentiation. CONCLUSIONS This work deepens our understanding of sexual differentiation in the vertebrate brain and defines a rich suite of molecular and cellular pathways that differentiate during adult sex change in anemonefish.
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Affiliation(s)
- Coltan G Parker
- Neuroscience Program, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL, 61820, USA
- Department of Biology, University of Maryland, College Park, MD, USA
| | - George W Gruenhagen
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Brianna E Hegarty
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Abigail R Histed
- Neuroscience Program, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL, 61820, USA
| | - Jeffrey T Streelman
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Justin S Rhodes
- Neuroscience Program, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL, 61820, USA.
- Department of Psychology, University of Illinois, Urbana-Champaign, 603 E. Daniel St., Champaign, IL, 61820, USA.
| | - Zachary V Johnson
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA.
- Emory National Primate Research Center, Emory University, 954 Gatewood Rd NE, Atlanta, GA, 30329, USA.
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3
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Roggenbuck EC, Hall EA, Hanson IB, Roby AA, Zhang KK, Alkatib KA, Carter JA, Clewner JE, Gelfius AL, Gong S, Gordon FR, Iseler JN, Kotapati S, Li M, Maysun A, McCormick EO, Rastogi G, Sengupta S, Uzoma CU, Wolkov MA, Clowney EJ. Let's talk about sex: Mechanisms of neural sexual differentiation in Bilateria. WIREs Mech Dis 2024; 16:e1636. [PMID: 38185860 DOI: 10.1002/wsbm.1636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 01/09/2024]
Abstract
In multicellular organisms, sexed gonads have evolved that facilitate release of sperm versus eggs, and bilaterian animals purposefully combine their gametes via mating behaviors. Distinct neural circuits have evolved that control these physically different mating events for animals producing eggs from ovaries versus sperm from testis. In this review, we will describe the developmental mechanisms that sexually differentiate neural circuits across three major clades of bilaterian animals-Ecdysozoa, Deuterosomia, and Lophotrochozoa. While many of the mechanisms inducing somatic and neuronal sex differentiation across these diverse organisms are clade-specific rather than evolutionarily conserved, we develop a common framework for considering the developmental logic of these events and the types of neuronal differences that produce sex-differentiated behaviors. This article is categorized under: Congenital Diseases > Stem Cells and Development Neurological Diseases > Stem Cells and Development.
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Affiliation(s)
- Emma C Roggenbuck
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Elijah A Hall
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Isabel B Hanson
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Alyssa A Roby
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Katherine K Zhang
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Kyle A Alkatib
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Joseph A Carter
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jarred E Clewner
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Anna L Gelfius
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Shiyuan Gong
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Finley R Gordon
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Jolene N Iseler
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Samhita Kotapati
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Marilyn Li
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Areeba Maysun
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Elise O McCormick
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Geetanjali Rastogi
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Srijani Sengupta
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Chantal U Uzoma
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - Madison A Wolkov
- MCDB 464 - Cellular Diversity: Sex Differentiation of the Brain, University of Michigan, Ann Arbor, Michigan, USA
| | - E Josephine Clowney
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
- Michigan Neuroscience Institute Affiliate, University of Michigan, Ann Arbor, Michigan, USA
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4
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Parker CG, Gruenhagen GW, Hegarty BE, Histed AR, Streelman JT, Rhodes JS, Johnson ZV. Adult sex change leads to extensive forebrain reorganization in clownfish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.29.577753. [PMID: 38352560 PMCID: PMC10862741 DOI: 10.1101/2024.01.29.577753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Sexual differentiation of the brain occurs in all major vertebrate lineages but is not well understood at a molecular and cellular level. Unlike most vertebrates, sex-changing fishes have the remarkable ability to change reproductive sex during adulthood in response to social stimuli, offering a unique opportunity to understand mechanisms by which the nervous system can initiate and coordinate sexual differentiation. This study explores sexual differentiation of the forebrain using single nucleus RNA-sequencing in the anemonefish Amphiprion ocellaris, producing the first cellular atlas of a sex-changing brain. We uncover extensive sex differences in cell type-specific gene expression, relative proportions of cells, baseline neuronal excitation, and predicted inter-neuronal communication. Additionally, we identify the cholecystokinin, galanin, and estrogen systems as central molecular axes of sexual differentiation. Supported by these findings, we propose a model of neurosexual differentiation in the conserved vertebrate social decision-making network spanning multiple subtypes of neurons and glia, including neuronal subpopulations within the preoptic area that are positioned to regulate gonadal differentiation. This work deepens our understanding of sexual differentiation in the vertebrate brain and defines a rich suite of molecular and cellular pathways that differentiate during adult sex change in anemonefish.
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Affiliation(s)
- Coltan G. Parker
- Neuroscience Program, University of Illinois, Urbana-Champaign, Illinois, USA
| | - George W. Gruenhagen
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Brianna E. Hegarty
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Abigail R. Histed
- Neuroscience Program, University of Illinois, Urbana-Champaign, Illinois, USA
| | - Jeffrey T. Streelman
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Justin S. Rhodes
- Neuroscience Program, University of Illinois, Urbana-Champaign, Illinois, USA
- Department of Psychology, University of Illinois, Urbana-Champaign, Illinois, USA
| | - Zachary V. Johnson
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
- Emory National Primate Research Center, Emory University, Atlanta, GA, USA
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5
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Herrera M, Ravasi T, Laudet V. Anemonefishes: A model system for evolutionary genomics. F1000Res 2023; 12:204. [PMID: 37928172 PMCID: PMC10624958 DOI: 10.12688/f1000research.130752.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/20/2023] [Indexed: 11/07/2023] Open
Abstract
Anemonefishes are an iconic group of coral reef fish particularly known for their mutualistic relationship with sea anemones. This mutualism is especially intriguing as it likely prompted the rapid diversification of anemonefish. Understanding the genomic architecture underlying this process has indeed become one of the holy grails of evolutionary research in these fishes. Recently, anemonefishes have also been used as a model system to study the molecular basis of highly complex traits such as color patterning, social sex change, larval dispersal and life span. Extensive genomic resources including several high-quality reference genomes, a linkage map, and various genetic tools have indeed enabled the identification of genomic features controlling some of these fascinating attributes, but also provided insights into the molecular mechanisms underlying adaptive responses to changing environments. Here, we review the latest findings and new avenues of research that have led to this group of fish being regarded as a model for evolutionary genomics.
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Affiliation(s)
- Marcela Herrera
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Timothy Ravasi
- Marine Climate Change Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
| | - Vincent Laudet
- Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
- Marine Research Station, Institute of Cellular and Organismic Biology (ICOB), Academia Sinica, 23-10, Dah-Uen Rd, Jiau Shi I-Lan 262, Taiwan
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6
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Parker CG, Craig SE, Histed AR, Lee JS, Ibanez E, Pronitcheva V, Rhodes JS. New cells added to the preoptic area during sex change in the common clownfish Amphiprion ocellaris. Gen Comp Endocrinol 2023; 333:114185. [PMID: 36509136 DOI: 10.1016/j.ygcen.2022.114185] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 11/26/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
Sex differences in cell number in the preoptic area of the hypothalamus (POA) are documented across all major vertebrate lineages and contribute to differential regulation of the hypothalamic-pituitary-gonad axis and reproductive behavior between the sexes. Sex-changing fishes provide a unique opportunity to study mechanisms underlying sexual differentiation of the POA. In anemonefish (clownfish), which change sex from male to female, females have approximately twice the number of medium-sized cells in the anterior POA compared to males. This sex difference transitions from male-like to female-like during sex change. However, it is not known how this sex difference in POA cell number is established. This study tests the hypothesis that new cell addition plays a role. We initiated adult male-to-female sex change in 30 anemonefish (Amphiprion ocellaris) and administered BrdU to label new cells added to the POA at regular intervals throughout sex change. Sex-changing fish added more new cells to the anterior POA than non-changing fish, supporting the hypothesis. The observed effects could be accounted for by differences in POA volume, but they are also consistent with a steady trickle of new cells being gradually accumulated in the anterior POA before vitellogenic oocytes develop in the gonads. These results provide insight into the unique characteristics of protandrous sex change in anemonefish relative to other modes of sex change, and support the potential for future research in sex-changing fishes to provide a richer understanding of the mechanisms for sexual differentiation of the brain.
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Affiliation(s)
- Coltan G Parker
- Neuroscience Program, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA
| | - Sarah E Craig
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA
| | - Abigail R Histed
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA
| | - Joanne S Lee
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA
| | - Emma Ibanez
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA
| | - Veronica Pronitcheva
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA
| | - Justin S Rhodes
- Neuroscience Program, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, 405 N Mathews Ave, Urbana, IL 61801, USA; Department of Psychology, University of Illinois, Urbana-Champaign, 603 E Daniel St, Urbana, IL 61801, USA.
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7
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Parker CG, Lee JS, Histed AR, Craig SE, Rhodes JS. Stable and persistent male-like behavior during male-to-female sex change in the common clownfish Amphiprion ocellaris. Horm Behav 2022; 145:105239. [PMID: 35926412 DOI: 10.1016/j.yhbeh.2022.105239] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 07/04/2022] [Accepted: 07/18/2022] [Indexed: 11/18/2022]
Abstract
Many fish species exhibit natural sex change as part of their life, providing unique opportunities to study sexually-differentiated social behaviors and their plasticity. Past research has shown that behavioral sex change in the female-to-male (protogynous) direction occurs rapidly and well before gonadal sex change. However, little is known about the timecourse of behavioral sex change in male-to-female (protandrous) sex-changing species, limiting our ability to compare patterns of behavioral sex change across species and identify conserved or divergent underlying mechanisms. Using the protandrous sex changing anemonefish Amphiprion ocellaris, we assessed behavior (aggression and parental care) and hormones (estradiol and 11-ketotestosterone) in fish over six months of sex change, and compared those fish against their non-changing partners as well as control males and females. Contrary to expectations, we found that sex-changing fish displayed behavior that was persistently male-like, and that their behavior did not become progressively female-like as sex change progressed. Hormones shifted to an intermediate profile between males and females and remained stable until gonads changed. These results support a new perspective that the timecourse for protandrous sex change in anemonefish is completely distinct from other well-established models, such that behavioral sex change does not occur until after gonadal sex change is complete, and that sex-changing fish have a stable and unique behavioral and hormonal phenotype that is distinct from a male-typical or female-typical phenotype. The results also identify aspects of sex change that may fundamentally differ between protandrous and protogynous modes, motivating further research into these remarkable examples of phenotypic plasticity.
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Affiliation(s)
- Coltan G Parker
- Neuroscience Program, University of Illinois, Urbana-Champaign, IL, USA
| | - Joanne S Lee
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, IL, USA
| | - Abigail R Histed
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, IL, USA
| | - Sarah E Craig
- Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, IL, USA
| | - Justin S Rhodes
- Neuroscience Program, University of Illinois, Urbana-Champaign, IL, USA; Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, IL, USA; Department of Psychology, University of Illinois, Urbana-Champaign, IL, USA.
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8
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Mitchell LJ, Tettamanti V, Rhodes JS, Marshall NJ, Cheney KL, Cortesi F. CRISPR/Cas9-mediated generation of biallelic F0 anemonefish (Amphiprion ocellaris) mutants. PLoS One 2021; 16:e0261331. [PMID: 34910772 PMCID: PMC8673619 DOI: 10.1371/journal.pone.0261331] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
Genomic manipulation is a useful approach for elucidating the molecular pathways underlying aspects of development, physiology, and behaviour. However, a lack of gene-editing tools appropriated for use in reef fishes has meant the genetic underpinnings for many of their unique traits remain to be investigated. One iconic group of reef fishes ideal for applying this technique are anemonefishes (Amphiprioninae) as they are widely studied for their symbiosis with anemones, sequential hermaphroditism, complex social hierarchies, skin pattern development, and vision, and are raised relatively easily in aquaria. In this study, we developed a gene-editing protocol for applying the CRISPR/Cas9 system in the false clown anemonefish, Amphiprion ocellaris. Microinjection of zygotes was used to demonstrate the successful use of our CRISPR/Cas9 approach at two separate target sites: the rhodopsin-like 2B opsin encoding gene (RH2B) involved in vision, and Tyrosinase-producing gene (tyr) involved in the production of melanin. Analysis of the sequenced target gene regions in A. ocellaris embryos showed that uptake was as high as 73.3% of injected embryos. Further analysis of the subcloned mutant gene sequences combined with amplicon shotgun sequencing revealed that our approach had a 75% to 100% efficiency in producing biallelic mutations in F0 A. ocellaris embryos. Moreover, we clearly show a loss-of-function in tyr mutant embryos which exhibited typical hypomelanistic phenotypes. This protocol is intended as a useful starting point to further explore the potential application of CRISPR/Cas9 in A. ocellaris, as a platform for studying gene function in anemonefishes and other reef fishes.
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Affiliation(s)
- Laurie J. Mitchell
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Valerio Tettamanti
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Justin S. Rhodes
- Department of Psychology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana, Champaign, Urbana, IL, United States of America
| | - N. Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Karen L. Cheney
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Fabio Cortesi
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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9
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Gonzalez JA, Histed AR, Nowak E, Lange D, Craig SE, Parker CG, Kaur A, Bhuvanagiri S, Kroll KJ, Martyniuk CJ, Denslow ND, Rosenfeld CS, Rhodes JS. Impact of bisphenol-A and synthetic estradiol on brain, behavior, gonads and sex hormones in a sexually labile coral reef fish. Horm Behav 2021; 136:105043. [PMID: 34507054 DOI: 10.1016/j.yhbeh.2021.105043] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 06/27/2021] [Accepted: 08/06/2021] [Indexed: 01/29/2023]
Abstract
Endocrine disrupting chemicals, such as bisphenol A (BPA) and ethinylestradiol (EE2), are detected in the marine environment from plastic waste and wastewater effluent. However, their impact on reproduction in sexually labile coral reef fish is unknown. The objective of this study was to determine impacts of environmentally relevant concentrations of BPA and EE2 on behavior, brain gene expression, gonadal histology, sex hormone profile, and plasma vitellogenin (Vtg) levels in the anemonefish, Amphiprion ocellaris. A. ocellaris display post-maturational sex change from male to female in nature. Sexually immature, male fish were paired together and fed twice daily with normal food (control), food containing BPA (100 μg/kg), or EE2 (0.02 μg/kg) (n = 9 pairs/group). Aggression toward an intruder male was measured at 1, 3, and 6 months. Blood was collected at 3 and 6 months to measure estradiol (E2), 11-ketotestosterone (11-KT), and Vtg. At the end of the study, fish were euthanized to assess gonad morphology and to measure expression of known sexually dimorphic genes in the brain. Relative to control, BPA decreased aggression, altered brain transcript levels, increased non-vitellogenic and vitellogenic eggs in the gonad, reduced 11-KT, and increased plasma Vtg. In two BPA-treated pairs, both individuals had vitellogenic eggs, which does not naturally occur. EE2 reduced 11-KT in subordinate individuals and altered expression of one transcript in the brain toward the female profile. Results suggest BPA, and to a lesser extent EE2, pollution in coral reef ecosystems could interfere with normal reproductive physiology and behavior of the iconic sexually labile anemonefish.
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Affiliation(s)
- Jose A Gonzalez
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Abigail R Histed
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Ewelina Nowak
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Dominica Lange
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Sarah E Craig
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Coltan G Parker
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America; The Neuroscience Program, University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Achint Kaur
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Supriya Bhuvanagiri
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America
| | - Kevin J Kroll
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, United States of America
| | - Christopher J Martyniuk
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, United States of America
| | - Nancy D Denslow
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, United States of America
| | - Cheryl S Rosenfeld
- Department of Biomedical Sciences, Bond Life Sciences Center, Thompson Center for Autism and Neurobehavioral Disorders, MU Institute for Data Science and Informatics, and Genetics Area Program, University of Missouri, Columbia, MO 65211, United States of America
| | - Justin S Rhodes
- The Beckman Institute for Advanced Science and Technology, University of Illinois, d0e N. Mathews Ave, Urbana, IL 61801, United States of America; The Neuroscience Program, University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801, United States of America; Department of Psychology, University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801, United States of America.
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10
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Casas L, Saborido-Rey F. Environmental Cues and Mechanisms Underpinning Sex Change in Fish. Sex Dev 2021; 15:108-121. [PMID: 34111868 DOI: 10.1159/000515274] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/07/2021] [Indexed: 11/19/2022] Open
Abstract
Fishes are the only vertebrates that undergo sex change during their lifetime, but even within this group, a unique reproductive strategy is displayed by only 1.5% of the teleosts. This lability in alternating sexual fate is the result of the simultaneous suppression and activation of opposing male and female networks. Here, we provide a brief review summarizing recent advances in our understanding of the environmental cues that trigger sex change and their perception, integration, and translation into molecular cascades that convert the sex of an individual. We particularly focus on molecular events underpinning the complex behavioral and morphological transformation involved in sex change, dissecting the main molecular players and regulatory networks that shape the transformation of one sex into the opposite. We show that histological changes and molecular pathways governing gonadal reorganization are better described than the neuroendocrine basis of sex change and that, despite important advances, information is lacking for the majority of hermaphrodite species. We highlight significant gaps in our knowledge of how sex change takes place and suggest future research directions.
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Affiliation(s)
- Laura Casas
- Ecology and Marine Resources, Institute of Marine Research (IIM-CSIC), Vigo, Spain
| | - Fran Saborido-Rey
- Ecology and Marine Resources, Institute of Marine Research (IIM-CSIC), Vigo, Spain
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11
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Roux N, Salis P, Lee SH, Besseau L, Laudet V. Anemonefish, a model for Eco-Evo-Devo. EvoDevo 2020; 11:20. [PMID: 33042514 PMCID: PMC7539381 DOI: 10.1186/s13227-020-00166-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/18/2020] [Indexed: 12/20/2022] Open
Abstract
Anemonefish, are a group of about 30 species of damselfish (Pomacentridae) that have long aroused the interest of coral reef fish ecologists. Combining a series of original biological traits and practical features in their breeding that are described in this paper, anemonefish are now emerging as an experimental system of interest for developmental biology, ecology and evolutionary sciences. They are small sized and relatively easy to breed in specific husbandries, unlike the large-sized marine fish used for aquaculture. Because they live in highly structured social groups in sea anemones, anemonefish allow addressing a series of relevant scientific questions such as the social control of growth and sex change, the mechanisms controlling symbiosis, the establishment and variation of complex color patterns, and the regulation of aging. Combined with the use of behavioral experiments, that can be performed in the lab or directly in the wild, as well as functional genetics and genomics, anemonefish provide an attractive experimental system for Eco-Evo-Devo.
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Affiliation(s)
- Natacha Roux
- Sorbonne Université, CNRS, UMR « Biologie Intégrative Des Organismes Marins », BIOM, 1, 66650 Banyuls-sur-Mer, France
| | - Pauline Salis
- Sorbonne Université, CNRS, UMR « Biologie Intégrative Des Organismes Marins », BIOM, 1, 66650 Banyuls-sur-Mer, France
| | - Shu-Hua Lee
- Lab of Marine Eco-Evo-Devo, Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Laurence Besseau
- Sorbonne Université, CNRS, UMR « Biologie Intégrative Des Organismes Marins », BIOM, 1, 66650 Banyuls-sur-Mer, France
| | - Vincent Laudet
- Lab of Marine Eco-Evo-Devo, Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.,Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna son, Okinawa, 904-0495 Japan
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12
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Spontaneous alloparental care of unrelated offspring by non-breeding Amphiprion ocellaris in absence of the biological parents. Sci Rep 2020; 10:4610. [PMID: 32165716 PMCID: PMC7067848 DOI: 10.1038/s41598-020-61537-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 02/24/2020] [Indexed: 11/08/2022] Open
Abstract
Many species display alloparental care, where individuals care for offspring that are not their own, but usually the behavior is contingent on the individual receiving some direct or indirect benefit. In anemonefish, after removing the breeding male, non-breeders have been observed providing care for eggs they did not sire and which are not kin. Previously this behavior was interpreted as coerced by the female. The purpose of this study was to test the alternative hypothesis that the alloparental care occurs spontaneously without prodding by the female. Groups of Amphiprion ocellaris (male, female and non-breeder) were maintained in the laboratory and behavior monitored after removing the male and both the male and female. Non-breeders began to care for eggs after male removal and further increased parental care after male and female removal. Level of care was not as high as experienced males, but additional experiments showed performance increases with experience. In a separate experiment, non-breeders were placed alone in a novel aquarium and eggs from an established spawning pair were introduced. Approximately 30% of the fish displayed extensive fathering behavior within 90 min. Taken together, our results demonstrate that fathering behavior in A. ocellaris occurs spontaneously, independent of paternity or kinship.
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13
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Southey BR, Rodriguez-Zas SL, Rhodes JS, Sweedler JV. Characterization of the prohormone complement in Amphiprion and related fish species integrating genome and transcriptome assemblies. PLoS One 2020; 15:e0228562. [PMID: 32163422 PMCID: PMC7067429 DOI: 10.1371/journal.pone.0228562] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 01/19/2020] [Indexed: 12/31/2022] Open
Abstract
The Amphiprion (anemonefish or clownfish) family of teleost fish, which is not a common model species, exhibits multiple unique characteristics, including social control of body size and protandrous sex change. The social changes in sex and body size are modulated by neuropeptide signaling pathways. These neuropeptides are formed from complex processing from larger prohormone proteins; understanding the neuropeptide complement requires information on complete prohormones sequences. Genome and transcriptome information within and across 22 teleost fish species, including 11 Amphiprion species, were assembled and integrated to achieve the first comprehensive survey of their prohormone genes. This information enabled the identification of 175 prohormone isoforms from 159 prohormone proteins across all species. This included identification of 9 CART prepropeptide genes and the loss of insulin-like 5B and tachykinin precursor 1B genes in Pomacentridae species. Transcriptome assemblies generally detected most prohormone genes but provided fewer prohormone genes than genome assemblies due to the lack of expression of prohormone genes or specific isoforms and tissue sampled. Comparisons between duplicate genes indicated that subfunctionalization, degradation, and neofunctionalization may be occurring between all copies. Characterization of the prohormone complement lays the foundation for future peptidomic investigation of the molecular basis of social physiology and behavior in the teleost fish.
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Affiliation(s)
- Bruce R. Southey
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Sandra L. Rodriguez-Zas
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Statistics, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Justin S. Rhodes
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Psychology, University of Illinois at Urbana−Champaign, Urbana, Illinois, United States of America
| | - Jonathan V. Sweedler
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois, United States of America
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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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Wang Y, Wu H, Sun ZS. The biological basis of sexual orientation: How hormonal, genetic, and environmental factors influence to whom we are sexually attracted. Front Neuroendocrinol 2019; 55:100798. [PMID: 31593707 DOI: 10.1016/j.yfrne.2019.100798] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/29/2019] [Accepted: 10/03/2019] [Indexed: 12/11/2022]
Abstract
Humans develop relatively stable attractions to sexual partners during maturation and present a spectrum of sexual orientation from homosexuality to heterosexuality encompassing varying degrees of bisexuality, with some individuals also displaying asexuality. Sexual orientation represents a basic life phenomenon for humans. However, the molecular mechanisms underlying these diverse traits of sexual orientation remain highly controversial. In this review, we systematically discuss recent advancements in sexual orientation research, including those related to measurements and associated brain regions. Current findings regarding sexual orientation modulation by hormonal, genetic, maternal immune system, and environmental factors are summarized in both human and model systems. We also emphasize that future studies should recognize the differences between males and females and pay more attention to minor traits and the epigenetic regulation of sexual orientation. A comprehensive view of sexual orientation may promote our understanding of the biological basis of sex, and that of human reproduction, and evolution.
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Affiliation(s)
- Yan Wang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Haoda Wu
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; Sino-Danish College, University of the Chinese Academy of Sciences, Beijing 100190, China
| | - Zhong Sheng Sun
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, China; Sino-Danish College, University of the Chinese Academy of Sciences, Beijing 100190, China; Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou 325000, China.
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