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Lee CJ, Lee HY, Yu YS, Ryu KB, Lee H, Kim K, Shin SY, Gil YC, Cho SJ. Brain compartmentalization based on transcriptome analyses and its gene expression in Octopus minor. Brain Struct Funct 2023:10.1007/s00429-023-02647-6. [PMID: 37138199 DOI: 10.1007/s00429-023-02647-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 04/17/2023] [Indexed: 05/05/2023]
Abstract
Coleoid cephalopods have a high intelligence, complex structures, and large brain. The cephalopod brain is divided into supraesophageal mass, subesophageal mass and optic lobe. Although much is known about the structural organization and connections of various lobes of octopus brain, there are few studies on the brain of cephalopod at the molecular level. In this study, we demonstrated the structure of an adult Octopus minor brain by histomorphological analyses. Through visualization of neuronal and proliferation markers, we found that adult neurogenesis occurred in the vL and posterior svL. We also obtained specific 1015 genes by transcriptome of O. minor brain and selected OLFM3, NPY, GnRH, and GDF8 genes. The expression of genes in the central brain showed the possibility of using NPY and GDF8 as molecular marker of compartmentation in the central brain. This study will provide useful information for establishing a molecular atlas of cephalopod brain.
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Affiliation(s)
- Chan-Jun Lee
- Department of Biological Sciences and Biotechnology, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Hae-Youn Lee
- Department of Biological Sciences and Biotechnology, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Yun-Sang Yu
- Department of Biological Sciences and Biotechnology, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Kyoung-Bin Ryu
- Clinical Research Division, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Chungbuk, 28159, Republic of Korea
| | - Hyerim Lee
- Department of Biological Sciences and Biotechnology, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Kyunghwan Kim
- Department of Biological Sciences and Biotechnology, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Song Yub Shin
- Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju, 61452, Republic of Korea.
| | - Young-Chun Gil
- Department of Anatomy, College of Medicine, Chungbuk National University, Cheongju, 28644, Republic of Korea.
| | - Sung-Jin Cho
- Department of Biological Sciences and Biotechnology, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.
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Zohar Y, Zmora N, Trudeau VL, Muñoz-Cueto JA, Golan M. A half century of fish gonadotropin-releasing hormones: Breaking paradigms. J Neuroendocrinol 2022; 34:e13069. [PMID: 34913529 DOI: 10.1111/jne.13069] [Citation(s) in RCA: 4] [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: 08/03/2021] [Revised: 11/18/2021] [Accepted: 11/18/2021] [Indexed: 12/11/2022]
Abstract
The field of fish gonadotropin-releasing hormones (GnRHs) is also celebrating its 50th anniversary this year. This review provides a chronological history of fish GnRH biology over the past five decades. It demonstrates how discoveries in fish regarding GnRH and GnRH receptor multiplicity, dynamic interactions between GnRH neurons, and additional neuroendocrine factors acting alongside GnRH, amongst others, have driven a paradigm shift in our understanding of GnRH systems and functions in vertebrates, including mammals. The role of technological innovations in enabling scientific discoveries is portrayed, as well as how fundamental research in fish GnRH led to translational outcomes in aquaculture. The interchange between fish and mammalian GnRH research is discussed, as is the value and utility of using fish models for advancing GnRH biology. Current challenges and future perspectives are presented, with the hope of expanding the dialogue and collaborations within the neuroendocrinology scientific community at large, capitalizing on diversifying model animals and the use of comparative strategies.
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Affiliation(s)
- Yonathan Zohar
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Nilli Zmora
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Vance L Trudeau
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - José A Muñoz-Cueto
- Department of Biology, Faculty of Marine and Environmental Sciences and University Institute of Marine Research (INMAR), University of Cádiz and European University of the Seas (SEA-EU), Puerto Real (Cádiz), Spain
| | - Matan Golan
- Institute of Animal Science, Agricultural Research Organization, Rishon Letziyon, Israel
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3
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Beltrán I, Herculano-Houzel S, Sinervo B, Whiting MJ. Are ectotherm brains vulnerable to global warming? Trends Ecol Evol 2021; 36:691-699. [PMID: 34016477 DOI: 10.1016/j.tree.2021.04.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/28/2022]
Abstract
Elevated temperatures during development affect a wide range of traits in ectotherms. Less well understood is the impact of global warming on brain development, which has only rarely been studied experimentally. Here, we evaluate current progress in the field and search for common response patterns among ectotherm groups. Evidence suggests that temperature may have a positive effect on neuronal activity and growth in developing brains, but only up to a threshold, above which temperature is detrimental to neuron development. These responses appear to be taxon dependent but this assumption may be due to a paucity of data for some taxonomic groups. We provide a framework with which to advance this highly promising field in the future.
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Affiliation(s)
- Iván Beltrán
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia.
| | - Suzana Herculano-Houzel
- Department of Psychology, Vanderbilt University, Nashville, TN, USA; Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - Barry Sinervo
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Martin J Whiting
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
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Macedo-Garzón B, Loredo-Ranjel R, Chávez-Maldonado M, Jiménez-Flores JR, Villamar-Duque TE, Cárdenas R. Distribution and expression of GnRH 1, kiss receptor 2, and estradiol α and ß receptors in the anterior brain of females of Chirostoma humboldtianum. FISH PHYSIOLOGY AND BIOCHEMISTRY 2021; 47:33-47. [PMID: 33118089 DOI: 10.1007/s10695-020-00891-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
Reproduction in vertebrates is a complex process regulated by many hormones, and by paracrine factors and their receptors. This study aimed to examine the expression of pjGonadotropin-releasing hormone (GnRH 1), the kisspeptin receptor 2 (kissr2), and estradiol receptors α and β (ER α and ER β) during different stages of the sexual cycle and their distribution within the anterior brain of females of Chirostoma humboldtianum. Among these molecules, the kissr2 showed the maximal variation in expression, while GnRH 1 showed minimal variation of expression, and ERβ and ERα had intermediate variation of expression. The distribution of these molecules in the anterior brain was consistent with their levels of expression; kissr2 was widely distributed throughout the telencephalon and diencephalon, while ER and GnRH 1 showed more restricted distributions. No coexpression of kissr2 and ER in GnRH 1ergic neurons, suggesting that regulation of this GnRH variant is indirectly mediated by kisspeptin and estradiol.
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Affiliation(s)
- Beatriz Macedo-Garzón
- Laboratorio de Endocrinología de peces, Unidad de Morfología y Función, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios # 1, Los Reyes Iztacacala, 54090, Tlalnepantla, Edo. de México, México
| | - Rosaura Loredo-Ranjel
- Laboratorio de Endocrinología de peces, Unidad de Morfología y Función, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios # 1, Los Reyes Iztacacala, 54090, Tlalnepantla, Edo. de México, México
| | - Mónica Chávez-Maldonado
- Laboratorio de Endocrinología de peces, Unidad de Morfología y Función, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios # 1, Los Reyes Iztacacala, 54090, Tlalnepantla, Edo. de México, México
| | - J Rafael Jiménez-Flores
- Laboratorio de Inmunología, Unidad de Morfología y Función, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de lo Barrios # 1, Los Reyes Iztacala, 54090, Tlalnepantla, Edo. de México, México
| | - Tomás E Villamar-Duque
- Bioterio General, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios # 1, Los Reyes Iztacala, 54090, Tlalnepantla, Edo. de México, México
| | - Rodolfo Cárdenas
- Laboratorio de Endocrinología de peces, Unidad de Morfología y Función, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios # 1, Los Reyes Iztacacala, 54090, Tlalnepantla, Edo. de México, México.
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Somoza GM, Mechaly AS, Trudeau VL. Kisspeptin and GnRH interactions in the reproductive brain of teleosts. Gen Comp Endocrinol 2020; 298:113568. [PMID: 32710898 DOI: 10.1016/j.ygcen.2020.113568] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/17/2020] [Accepted: 07/19/2020] [Indexed: 02/09/2023]
Abstract
It is well known that gonadotropin-releasing hormone (Gnrh) has a key role in reproduction by regulating the synthesis and release of gonadotropins from the anterior pituitary gland of all vertebrates. About 25 years ago, another neuropeptide, kisspeptin (Kiss1) was discovered as a metastasis suppressor of melanoma cell lines and then found to be essential for mammalian reproduction as a stimulator of hypothalamic Gnrh and regulator of puberty onset. Soon after, a kisspeptin receptor (kissr) was found in the teleost brain. Nowadays, it is known that in most teleosts the kisspeptin system is composed of two ligands, kiss1 and kiss2, and two receptors, kiss2r and kiss3r. Even though both kisspeptin peptides, Kiss1 and Kiss2, have been demonstrated to stimulate gonadotropin synthesis and secretion in different fish species, their actions appear not to be mediated by Gnrh neurons as in mammalian models. In zebrafish and medaka, at least, hypophysiotropic Gnrh neurons do not express Kiss receptors. Furthermore, kisspeptinergic nerve terminals reach luteinizing hormone cells in some fish species, suggesting a direct pituitary action. Recent studies in zebrafish and medaka with targeted mutations of kiss and/or kissr genes reproduce relatively normally. In zebrafish, single gnrh mutants and additionally those having the triple gnrh3 plus 2 kiss mutations can reproduce reasonably well. In these fish, other neuropeptides known to affect gonadotropin secretion were up regulated, suggesting that they may be involved in compensatory responses to maintain reproductive processes. In this context, the present review explores and presents different possibilities of interactions between Kiss, Gnrh and other neuropeptides known to affect reproduction in teleost fish. Our intention is to stimulate a broad discussion on the relative roles of kisspeptin and Gnrh in the control of teleost reproduction.
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Affiliation(s)
- Gustavo M Somoza
- Instituto Tecnológico de Chascomús (CONICET-UNSAM), Chascomús, Buenos Aires B7130IWA, Argentina.
| | - Alejandro S Mechaly
- Instituto de Investigaciones en Biodiversidad y Biotecnología (CONICET), Mar del Plata, Buenos Aires 7600, Argentina.
| | - Vance L Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
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Nyuji M, Hongo Y, Yoneda M, Nakamura M. Transcriptome characterization of BPG axis and expression profiles of ovarian steroidogenesis-related genes in the Japanese sardine. BMC Genomics 2020; 21:668. [PMID: 32993516 PMCID: PMC7526130 DOI: 10.1186/s12864-020-07080-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/18/2020] [Indexed: 11/10/2022] Open
Abstract
Background The clupeoid fishes are ecologically and commercially important fish species worldwide that exhibit a high level of population fluctuation, accompanied by alteration of reproductive traits. However, knowledge about their reproductive physiology in order to understand mechanisms underlying such population dynamics is limited. The endocrine system along with the brain–pituitary–gonadal (BPG) axis is critical for regulating reproduction. The aims of this study were to provide transcript data and genes related to the BPG axis, and to characterize the expression profiles of ovarian steroidogenesis-related genes in the Japanese sardine (Sardinops melanostictus, Clupeidae). Results RNA sequencing was performed using the sardine brain, pituitary, and gonad in both sexes. A total of 290,119 contigs were obtained and 115,173 non-redundant ORFs were annotated. The genes differentially expressed between ovary and testis were strongly associated with GO terms related to gamete production. The tissue-specific profile of the abundance of transcripts was characterized for the major regulators in the BPG axis, such as gonadotropin-releasing hormone, gonadotropin, and steroidogenic enzyme. By comparing between ovary and testis, out of eight different 17β-hydroxysteroid dehydrogenase (Hsd17b) genes identified, higher hsd17b7 expression was found in testis, whereas higher expression of hsd17b8, hsd17b10, hsd17b12a, and hsd17b12b was found in ovary. The cDNAs encoding key endocrine factors in the ovarian steroidogenic pathway were cloned, sequenced, and quantitatively assayed. In the pituitary, follicle-stimulating hormone beta peaked during vitellogenesis, while luteinizing hormone beta peaked at the completion of vitellogenesis. In the ovary, follicle-stimulating hormone receptor and luteinizing hormone receptor were upregulated from mid- to late phase of vitellogenesis. Furthermore, three steroidogenic enzyme genes (cyp11a1, cyp17a1, and cyp19a1a) gradually increased their expression during ovarian development, accompanying a rise in serum estradiol-17β, while 3β-hydroxysteroid dehydrogenase and steroidogenic acute regulatory protein did not change significantly. Conclusions This is the first report of deep RNA sequencing analysis of Japanese sardine, in which many key genes involved in the BPG axis were identified. Expression profiles of ovarian steroidogenesis-related genes provide a molecular basis of the physiological processes underlying ovarian development in the sardine. Our study will be a valuable resource for clarifying the molecular biology of clupeoid fishes.
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Affiliation(s)
- Mitsuo Nyuji
- Fisheries Resources Institute, Japan Fisheries Research and Education Agency, Yokohama, 236-8648, Japan.
| | - Yuki Hongo
- Fisheries Resources Institute, Japan Fisheries Research and Education Agency, Yokohama, 236-8648, Japan
| | - Michio Yoneda
- Hakatajima Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Kinoura, Imabari, Ehime, 794-2305, Japan
| | - Masahiro Nakamura
- Hakatajima Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Kinoura, Imabari, Ehime, 794-2305, Japan
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Zhong H, Hu J, Zhou Y. Transcriptomic evidence of luteinizing hormone-releasing hormone agonist (LHRH-A) regulation on lipid metabolism in grass carp (Ctenopharyngodon idella). Genomics 2020; 113:1265-1271. [PMID: 32971214 DOI: 10.1016/j.ygeno.2020.09.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/08/2020] [Accepted: 09/20/2020] [Indexed: 11/24/2022]
Abstract
In this study, RNA sequencing was used to identify the hepatic gene expression profile in grass carp associated with luteinizing hormone-releasing hormone agonist (LHRH-A) treatment. A total of 93,912,172 reads were generated by HiSeq 4000 sequencing platform. After filtering, 83,450,860 clean reads were mapped to the reference genome. By calculating the FPKM of genes, 1475 differentially expressed genes were identified. PPAR signaling pathway was enriched with upregulated genes in LHRH-A injection group showing the regulation of the lipid metabolism by LHRH-A. The expression of eight key genes in PPAR signaling pathway was confirmed by qPCR and the results suggested that ACSL4A, ACSL4B, ANGPTL4, LPL, RXRBA and SLC27A1B were significantly stimulated by LHRH-A injection. This investigation provides the evidence that LHRH-A could play a role in lipid metabolism.
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Affiliation(s)
- Huan Zhong
- College of Animal Science and Technology, Hunan Agriculture University, Changsha 410128, China
| | - Jie Hu
- Key Laboratory of Tropical & Subtropical Fisheries Resource Application & Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510385, China.
| | - Yi Zhou
- State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, China; Life Science College, Hunan Normal University, Changsha 410081, China.
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8
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Parker CG, Cheung E. Metabolic control of teleost reproduction by leptin and its complements: Understanding current insights from mammals. Gen Comp Endocrinol 2020; 292:113467. [PMID: 32201232 DOI: 10.1016/j.ygcen.2020.113467] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/05/2020] [Accepted: 03/18/2020] [Indexed: 12/15/2022]
Abstract
Reproduction is expensive. Hence, reproductive physiology is sensitive to an array of endogenous signals that provide information on metabolic and nutritional sufficiency. Although metabolic gating of reproductive function in mammals, as evidenced by studies demonstrating delayed puberty and perturbed fertility, has long been understood to be a function of energy sufficiency, an understanding of the endocrine regulators of this relationship have emerged only within recent decades. Peripheral signals including leptin and cortisol have long been implicated in the physiological integration of metabolism and reproduction. Recent studies have begun to explore possible roles for these two hormones in the regulation of reproduction in teleost fishes, as well as a role for leptin as a catabolic stress hormone. In this review, we briefly explore the reproductive actions of leptin and cortisol in mammals and teleost fishes and possible role of both hormones as putative modulators of the reproductive axis during stress events.
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Affiliation(s)
- Coltan G Parker
- Neuroscience Program, Beckman Institute of Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N Mathews Ave, Urbana, IL, USA
| | - Eugene Cheung
- Department of Biological Sciences, David Clark Labs, 100 Brooks Avenue, North Carolina State University, Raleigh, NC, USA.
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9
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Blanco AM. Hypothalamic- and pituitary-derived growth and reproductive hormones and the control of energy balance in fish. Gen Comp Endocrinol 2020; 287:113322. [PMID: 31738909 DOI: 10.1016/j.ygcen.2019.113322] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 10/20/2019] [Accepted: 11/12/2019] [Indexed: 02/07/2023]
Abstract
Most endocrine systems in the body are influenced by the hypothalamic-pituitary axis. Within this axis, the hypothalamus delivers precise signals to the pituitary gland, which in turn releases hormones that directly affect target tissues including the liver, thyroid gland, adrenal glands and gonads. This action modulates the release of additional hormones from the sites of action, regulating key physiological processes, including growth, metabolism, stress and reproduction. Pituitary hormones are released by five distinct hormone-producing cell types: somatotropes (which produce growth hormone), thyrotropes (thyrotropin), corticotropes (adrenocorticotropin), lactotropes (prolactin) and gonadotropes (follicle stimulating hormone and luteinizing hormone), each modulated by specific hypothalamic signals. This careful and distinct organization of the hypothalamo-pituitary axis has been classically associated with the existence of many lineal axes (e.g., the hypothalamic-pituitary-gonadal axis) in charge of the control of the different physiological processes. While this traditional concept is valid, it is becoming apparent that hormones produced by the hypothalamo-pituitary axis have diverse effects. For instance, gonadotropin-releasing hormone II has been associated with a suppressive effect on food intake in fish. Likewise, growth hormone has been shown to influence appetite, swimming activity and aggressive behavior in fish. This review will focus on the hypothalamic and pituitary hormones classically involved in regulating growth and reproduction, and will attempt to provide a general overview of the current knowledge on their actions on energy balance and appetite in fish. It will also give a brief perspective of the role of some of these peptides in integrating feeding, metabolism, growth and reproduction.
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Affiliation(s)
- Ayelén M Blanco
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Vigo, Pontevedra, Spain; Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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10
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Di Yorio MP, Pérez Sirkin DI, Muñoz-Cueto JA, Delgadin TH, Tsutsui K, Somoza GM, Vissio PG. Morphological relationship between GnIH and GnRH neurons in the brain of the neotropical cichlid fish Cichlasoma dimerus. Gen Comp Endocrinol 2019; 273:144-151. [PMID: 29913169 DOI: 10.1016/j.ygcen.2018.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/28/2018] [Accepted: 06/15/2018] [Indexed: 01/23/2023]
Abstract
Reproduction is regulated by the hypothalamic-pituitary-gonadal axis. The first neuropeptide identified that regulates this function was the decapeptide gonadotropin-releasing hormone (GnRH). Nowadays, in gnatostomates, a number of GnRH variants have been identified and classified into three different types: GnRH1, GnRH2, and GnRH3. Almost 30 years later, a new peptide that inhibits gonadotropin synthesis and secretion was discovered and thus named as gonadotropin-inhibitory hormone (GnIH). In avians and mammals, the interaction and regulation between GnRH and GnIH neurons has been widely studied; however, in other vertebrate groups there is little information about the relationship between these neurons. In previous works, three GnRH variants and a GnIH propeptide were characterized in Cichlasoma dimerus, and it was demonstrated that GnIH inhibited gonadotropins release in this species. Because no innervation was detected at the pituitary level, we speculate that GnIH would inhibit gonadotropins via GnRH. Thus, the aim of the present study was to evaluate the anatomical relationship between neurons expressing GnIH and the three GnRH variants by double labelling confocal immunofluorescence in adults of C. dimerus. Our results showed no apparent contacts between GnIH and GnRH1, fiber to fiber interactions between GnIH and GnRH2, and co-localization of GnIH and GnRH3 variant in neurons of the nucleus olfacto-retinalis. In conclusion, whether GnIH regulates the expression or secretion of GnRH1 in this species, an indirect modulation seems more plausible. Moreover, the present results suggest an interaction between GnIH and GnRH2 systems. Finally, new clues were provided to investigate the role of nucleus olfacto-retinalis cells and putative GnIH and GnRH3 interactions in the modulation of the reproductive network in teleost fish.
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Affiliation(s)
- María P Di Yorio
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina; Intituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Daniela I Pérez Sirkin
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina; Intituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - José A Muñoz-Cueto
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cádiz, Marine Campus of International Excellence (CEIMAR) and Agrifood Campus of International Excellence (ceiA3), INMAR-CACYTMAR Research Institutes, Puerto Real University Campus, Puerto Real, Spain
| | - Tomás H Delgadin
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina; Intituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Kazuyoshi Tsutsui
- Department of Biology and Center for Medical Life Science, Waseda University, Tokyo 162-8480, Japan
| | - Gustavo M Somoza
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús, CONICET-UNSAM, Chascomús, Argentina
| | - Paula G Vissio
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina; Intituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.
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11
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Qin QB, Liu QW, Zhou YW, Wang CQ, Qin H, Zhao C, Liu SJ. Differential expression of HPG-axis genes in autotetraploids derived from red crucian carp Carassius auratus red var., ♀ × blunt snout bream Megalobrama amblycephala, ♂. JOURNAL OF FISH BIOLOGY 2018; 93:1082-1089. [PMID: 30260011 DOI: 10.1111/jfb.13818] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 09/22/2018] [Indexed: 06/08/2023]
Abstract
Autotetraploid fish (4n = 200, abbreviated as 4nRR), which reach sexual maturity at 1 year of age, were derived from the whole genome duplication of red crucian carp Carassius auratus red var. (RCC; 2n = 100) and possess four sets of chromosomes from RCC. The histological features of the gonads showed that the RCC and 4nRR both possessed normal gonadal structure and could arrive at maturation. To understand the expression characteristics of genes related to reproductive development in the autotetraploid fish, we analysed the nucleotide sequence and expression characteristics of the gnrh2, gthb and gthr genes, which are the pivotal genes of the hypothalamic-pituitary-gonadal (HPG) axis. We found that the gnrh2, gthb and gthr genes in 4nRR share remarkable homology with RCC, but there were obvious differences in expression levels between 4nRR and RCC. These results demonstrate that autotetraploidization can lead to gene expression changes. This study provides insights into the molecular mechanism underlying the reproductive development of autotetraploid fish and is expected to be of great significance for subsequent research on polyploidization.
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Affiliation(s)
- Qin B Qin
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Qi W Liu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yu W Zhou
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Chong Q Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Huan Qin
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Chun Zhao
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Shao J Liu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, China
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12
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London S, Volkoff H. Cloning and effects of fasting on the brain expression levels of appetite-regulators and reproductive hormones in glass catfish (Kryptopterus vitreolus). Comp Biochem Physiol A Mol Integr Physiol 2018; 228:94-102. [PMID: 30453036 DOI: 10.1016/j.cbpa.2018.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/11/2018] [Accepted: 11/12/2018] [Indexed: 10/27/2022]
Abstract
The regulation of feeding is a complex process that involves coordination between various signals. Feeding hormones can be described as orexigenic (stimulate food intake, e.g. orexin and neuropeptide Y - NPY) or anorexigenic (inhibit food intake, e.g. cocaine and amphetamine regulated transcript - CART). Reproduction and energy homeostasis are closely linked, as factors that affect appetite have also been shown to influence reproductive hormones and behaviors. Gonadotropin-releasing hormone (GnRH) is one of the most influential factors controlling reproduction. Although our understanding of the endocrine regulation of feeding and reproduction in fish is progressing, many gaps still remain, particularly in catfish. Glass catfish (Kryptopterus vitreolus) are freshwater fish known for their natural transparency. In this study, we isolated cDNA encoding reproductive hormones (GnRH1, GnRH2) and appetite regulators (orexin, NPY, and CART) from glass catfish and examined their distribution in various tissues. All peptides had wide distributions across various brain and peripheral tissues, except CART, which was only present in brain. In order to assess whether limited energy supply affects these peptides, we examined the effects of fasting on their brain mRNA expression levels. Fasting increased the expression of both the orexigenic (i.e. orexin and NPY) and anorexigenic (i.e. CART) hormones, and decreased expression levels of GnRH1, but did not affect GnRH2. Overall, our results suggest that fasting affects the expression of peptides involved in both feeding and reproduction, and provides new insights on the endocrine mechanisms that regulate feeding and reproduction in catfish.
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Affiliation(s)
- Sydney London
- Departments of Biology and Biochemistry, Memorial University of Newfoundland, St. John, NL A1B 3X9, Canada
| | - Helene Volkoff
- Departments of Biology and Biochemistry, Memorial University of Newfoundland, St. John, NL A1B 3X9, Canada.
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13
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Zhai G, Shu T, Xia Y, Lu Y, Shang G, Jin X, He J, Nie P, Yin Z. Characterization of Sexual Trait Development in cyp17a1-Deficient Zebrafish. Endocrinology 2018; 159:3549-3562. [PMID: 30202919 DOI: 10.1210/en.2018-00551] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/30/2018] [Indexed: 12/16/2022]
Abstract
Cytochrome P450 (Cyp)17A1 has both 17α-hydroxylase and 17,20-lyase activities, which are involved in the steroidogenic pathway that produces androgens and estrogens. Previously, a phenotype of all-male cyp17a1-deficient zebrafish generated by transcription activatorlike effector nuclease has been reported. In the current study, the mechanisms relating to Cyp17a1 that are involved in the development of sexual traits, especially gonadal differentiation and testicular development, were characterized. We found that the cyp17a1-deficient fish at 3 months postfertilization (mpf) were all fertile males with normal testis and spermatogenesis but compromised male-typical mating behaviors and secondary sex characters (SSCs), including breeding tubercles, body pigmentation, and anal fin coloration. These results demonstrate that spermatogenesis and testicular development are not as susceptible to androgen deficiency compared with the formation of male-typical SSCs and mating behaviors in zebrafish. The differentiation of the juvenile ovary into the mature ovary failed during the critical sexual differentiation stage. This all-male phenotype of the cyp17a1-deficient fish could be restored with testosterone or estradiol treatment. For testicular development in cyp17a1-deficient fish, a gradually increasing number of spermatozoa and testis hypertrophy from 3 to 6 mpf were observed, accompanied by constitutively upregulated pituitary gonadotropin FSH subunit β (fshβ). The hypertrophic testis and enhanced spermatogenesis in the cyp17a1-deficient fish at 6 mpf could be effectively rescued by fshβ depletion. These results confirm that adequate estrogen is essential for maintaining ovarian differentiation, and they provide new insight into the role of FSHβ in male testicular development and spermatogenesis.
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Affiliation(s)
- Gang Zhai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Tingting Shu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yuguo Xia
- Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Yao Lu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guohui Shang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xia Jin
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Jiangyan He
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Pin Nie
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Zhan Yin
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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14
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Edwards A, Jones SM. Response to gonadotropin-releasing hormone challenge: Seasonal variation in steroid production in a viviparous lizard, Tiliqua nigrolutea. Gen Comp Endocrinol 2017; 244:70-76. [PMID: 26551889 DOI: 10.1016/j.ygcen.2015.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 10/30/2015] [Accepted: 11/02/2015] [Indexed: 10/22/2022]
Abstract
The hypothalamic-pituitary-gonadal axis plays a central role in the regulation of gamete maturation, sex steroid production and the stimulation of reproductive behaviours in vertebrates. In seasonal breeders, the timely activation and deactivation of this control system is important to ensure successful reproduction: this process is not well understood in species which breed irregularly. Males of the viviparous blotched blue-tongued lizard, Tiliqua nigrolutea, breed annually, while females display a multiennial cycle. We investigated seasonal variation in hypothalamic-pituitary-gonadal axis responsiveness in both sexes of T. nigrolutea. We measured changes in plasma concentrations of testosterone and estrogen in response to a single intraperitoneal injection of a GnRH agonist, chicken-II LH-RH, at three reproductively distinct times of year. Plasma testosterone concentrations in males were significantly increased during gonadal quiescence, but not initial or final spermatogenesis. There was no estrogen response in males at any time of year. Conversely, in females, there was an increase in plasma testosterone, but not estrogen, concentration, in reproductively quiescent females several months in advance of a successful pregnancy. These results indicate clear variation in HPG axis activity with sex, season and reproductive condition in this seasonally breeding viviparous lizard. This study opens the way for further investigation into the mechanisms by which internal (body condition) and external seasonal cues (temperature and photoperiod) are coordinated to regulate reproduction in irregularly-breeding reptiles.
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Affiliation(s)
- Ashley Edwards
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
| | - Susan M Jones
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
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15
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Li L, Wojtowicz JL, Malin JH, Huang T, Lee EB, Chen Z. GnRH-mediated olfactory and visual inputs promote mating-like behaviors in male zebrafish. PLoS One 2017; 12:e0174143. [PMID: 28329004 PMCID: PMC5362193 DOI: 10.1371/journal.pone.0174143] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 03/03/2017] [Indexed: 01/13/2023] Open
Abstract
The engagement of sexual behaviors is regulated by a number of factors which include gene expression, hormone circulation, and multi-sensory information integration. In zebrafish, when a male and a female are placed in the same container, they show mating-like behaviors regardless of whether they are kept together or separated by a net. No mating-like behaviors are observed when same-sex animals are put together. Through the olfacto-visual centrifugal pathway, activation of the terminalis nerve in the olfactory bulb increases GnRH signaling in the brain and triggers mating-like behaviors between males. In zebrafish mutants or wild-type fish in which the olfacto-visual centrifugal pathway is impaired or chemically ablated, in response to odor stimulation the mating-like behaviors between males are no longer evident. Together, the data suggest that the combination of olfactory and visual signals alter male zebrafish's mating-like behaviors via GnRH signaling.
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Affiliation(s)
- Lei Li
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States of America
- * E-mail:
| | - Jennifer L. Wojtowicz
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States of America
| | - John H. Malin
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States of America
| | - Tao Huang
- Center for Reproductive Medicine, Shandong University, Jinan,China
| | - Eric B. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States of America
| | - Zijiang Chen
- Center for Reproductive Medicine, Shandong University, Jinan,China
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16
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Jadhao AG, Pinelli C, D'Aniello B, Tsutsui K. Gonadotropin-inhibitory hormone (GnIH) in the amphibian brain and its relationship with the gonadotropin releasing hormone (GnRH) system: An overview. Gen Comp Endocrinol 2017; 240:69-76. [PMID: 27667155 DOI: 10.1016/j.ygcen.2016.09.006] [Citation(s) in RCA: 14] [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: 03/29/2016] [Revised: 09/02/2016] [Accepted: 09/14/2016] [Indexed: 01/28/2023]
Abstract
It is well known that the hypothalamic neuropeptide gonadotropin-releasing hormone (GnRH) plays an important role as a primary factor regulating gonadotropin secretion in reproductive processes in vertebrates. The discovery of the presence of a gonadotropin-inhibitory hormone (GnIH) in the brains of birds has further contributed to our understanding of the reproduction control by the brain. GnIH plays a key role in inhibition of reproduction and acts on the pituitary gland and GnRH neurons via a novel G protein-coupled receptor (GPR147). GnIH decreases gonadotropin synthesis and release, thus inhibiting gonadal development and maintenance. The GnRH and GnIH neuronal peptidergic systems are well reported in mammals and birds, but limited information is available regarding their presence and localization in the brains of other vertebrate species, such as reptiles, amphibians and fishes. The aim of this review is to compile and update information on the localization of GnRH and GnIH neuronal systems, with a particular focus on amphibians, summarizing the neuroanatomical distribution of GnIH and GnRH and emphasizing the discovery of GnIH based on RFamide peptides and GnIH orthologous peptides found in other vertebrates and their functional significance.
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Affiliation(s)
- Arun G Jadhao
- Department of Zoology, RTM Nagpur University Campus, Nagpur 440 033, MS, India.
| | - Claudia Pinelli
- Department of Environmental, Biological, and Pharmaceutical Sciences & Technologies, Second University of Naples, 81100 Caserta, Italy
| | - Biagio D'Aniello
- Department of Biology, University of Naples "Federico II", 80126 Napoli, Italy
| | - Kazuyoshi Tsutsui
- Laboratory of Integrative Brain Sciences, Department of Biology and Centre for Medical Life Science, Waseda University, Tokyo 162-8480, Japan
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17
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Metallinou C, Asimakopoulos B, Schröer A, Nikolettos N. Gonadotropin-Releasing Hormone in the Ovary. Reprod Sci 2016; 14:737-49. [DOI: 10.1177/1933719107310707] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Chryssa Metallinou
- Department of Physiology, School of Medicine, Democritus University of Thrace, Dragana, Greece
| | - Byron Asimakopoulos
- Department of Physiology, School of Medicine, Democritus University of Thrace, Dragana, Greece
| | - Andreas Schröer
- Department of Obstetrics/Gynecology, University Klinik of Schleswig-Holstein, Lübeck, Germany
| | - Nikos Nikolettos
- Department of Physiology, School of Medicine, Democritus University of Thrace, Dragana, Greece
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18
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Charif SE, Inserra PIF, Di Giorgio NP, Schmidt AR, Lux-Lantos V, Vitullo AD, Dorfman VB. Sequence analysis, tissue distribution and molecular physiology of the GnRH preprogonadotrophin in the South American plains vizcacha (Lagostomus maximus). Gen Comp Endocrinol 2016; 232:174-84. [PMID: 26704854 DOI: 10.1016/j.ygcen.2015.12.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 12/10/2015] [Accepted: 12/14/2015] [Indexed: 12/14/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) is the regulator of the hypothalamic-hypophyseal-gonadal (HHG) axis. GnRH and GAP (GnRH-associated protein) are both encoded by a single preprohormone. Different variants of GnRH have been described. In most mammals, GnRH is secreted in a pulsatile manner that stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The South-American plains vizcacha, Lagostomus maximus, is a rodent with peculiar reproductive features including natural poly-ovulation up to 800 oocytes per estrous cycle, pre-ovulatory follicle formation throughout pregnancy and an ovulatory process which takes place at mid-gestation and adds a considerable number of secondary corpora lutea. Such features should occur under a special modulation of the HHG axis, guided by GnRH. The aim of this study was to sequence hypothalamic GnRH preprogonadotrophin mRNA in the vizcacha, to compare it with evolutionarily related species and to identify its expression, distribution and pulsatile pattern of secretion. The GnRH1variant was detected and showed the highest homology with that of chinchilla, its closest evolutionarily related species. Two isoforms of transcripts were identified, carrying the same coding sequence, but different 5' untranslated regions. This suggests a sensitive equilibrium between RNA stability and translational efficiency. A predominant hypothalamic localization and a pulsatile secretion pattern of one pulse of GnRH every hour were found. The lower homology found for GAP, also among evolutionarily related species, depicts a potentially different bioactivity.
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Affiliation(s)
- Santiago Elías Charif
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Pablo Ignacio Felipe Inserra
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Noelia Paula Di Giorgio
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IByME)-CONICET, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandro Raúl Schmidt
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Victoria Lux-Lantos
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IByME)-CONICET, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Alfredo Daniel Vitullo
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Verónica Berta Dorfman
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Argentina.
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19
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Alvarado SG, Lenkov K, Williams B, Fernald RD. Social Crowding during Development Causes Changes in GnRH1 DNA Methylation. PLoS One 2015; 10:e0142043. [PMID: 26517121 PMCID: PMC4627844 DOI: 10.1371/journal.pone.0142043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 10/16/2015] [Indexed: 12/30/2022] Open
Abstract
Gestational and developmental cues have important consequences for long-term health, behavior and adaptation to the environment. In addition, social stressors cause plastic molecular changes in the brain that underlie unique behavioral phenotypes that also modulate fitness. In the adult African cichlid, Astatotilapia burtoni, growth and social status of males are both directly regulated by social interactions in a dynamic social environment, which causes a suite of plastic changes in circuits, cells and gene transcription in the brain. We hypothesized that a possible mechanism underlying some molecular changes might be DNA methylation, a reversible modification made to cytosine nucleotides that is known to regulate gene function. Here we asked whether changes in DNA methylation of the GnRH1 gene, the central regulator of the reproductive axis, were altered during development of A. burtoni. We measured changes in methylation state of the GnRH1 gene during normal development and following the gestational and developmental stress of social crowding. We found differential DNA methylation within developing juveniles between 14-, 28- and 42-day-old. Following gestational crowding of mouth brooding mothers, we saw differential methylation and transcription of GnRH1 in their offspring. Taken together, our data provides evidence for social control of GnRH1 developmental responses to gestational cues through DNA methylation.
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Affiliation(s)
- Sebastian G Alvarado
- Biology Department and Neuroscience Institute, Gilbert Hall, Stanford University, 371 Serra Mall, Stanford, Palo Alto, Califorinia 94305, United States of America
| | - Kapa Lenkov
- Biology Department and Neuroscience Institute, Gilbert Hall, Stanford University, 371 Serra Mall, Stanford, Palo Alto, Califorinia 94305, United States of America
| | - Blake Williams
- Biology Department and Neuroscience Institute, Gilbert Hall, Stanford University, 371 Serra Mall, Stanford, Palo Alto, Califorinia 94305, United States of America
| | - Russell D Fernald
- Biology Department and Neuroscience Institute, Gilbert Hall, Stanford University, 371 Serra Mall, Stanford, Palo Alto, Califorinia 94305, United States of America
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20
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Shao YT, Tseng YC, Chang CH, Yan HY, Hwang PP, Borg B. GnRH mRNA levels in male three-spined sticklebacks, Gasterosteus aculeatus, under different reproductive conditions. Comp Biochem Physiol A Mol Integr Physiol 2015; 180:6-17. [DOI: 10.1016/j.cbpa.2014.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 10/09/2014] [Accepted: 10/16/2014] [Indexed: 11/27/2022]
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21
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Roch GJ, Busby ER, Sherwood NM. GnRH receptors and peptides: skating backward. Gen Comp Endocrinol 2014; 209:118-34. [PMID: 25107740 DOI: 10.1016/j.ygcen.2014.07.025] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 07/22/2014] [Accepted: 07/28/2014] [Indexed: 11/18/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) and its receptor are essential for reproduction in vertebrates. Although there are three major types of GnRH peptides and two major types of receptors in vertebrates, the pattern of distribution is unusual. Evidence is presented from genome mining that type I GnRHRs are not restricted to mammals, but can be found in the lobe-finned and cartilaginous fishes. This implies that this tail-less GnRH receptor emerged early in vertebrate evolution, followed by several independent losses in different lineages. Also, we have identified representatives from the three major GnRH peptide types (mammalian GnRH1, vertebrate GnRH2 and dogfish GnRH3) in a single cartilaginous fish, the little skate. Skate and coelacanth are the only examples of animals with both type I and II GnRH receptors and all three peptide types, suggesting this was the ancestral condition in vertebrates. Our analysis of receptor synteny in combination with phylogeny suggests that there were three GnRH receptor types present before the two rounds of whole genome duplication in early vertebrates. To further understand the origin of the GnRH peptide-receptor system, the relationship of vertebrate and invertebrate homologs was examined. Our evidence supports the hypothesis of a GnRH superfamily with a common ancestor for the vertebrate GnRHs, invertebrate (inv)GnRHs, corazonins and adipokinetic hormones. The invertebrate deuterostomes (echinoderms, hemichordates and amphioxus) have derived GnRH-like peptides, although one amphioxus GnRH with a syntenic relationship to human GnRHs has been shown to be functional. Phylogenetic analysis suggests that gene duplications in the ancestral bilaterian produced two receptor types, one of which became adipokinetic hormone receptor/GnRHR and the other corazonin receptor/invGnRHR. It appears that the ancestral deuterostome had both a GnRHR and invGnRHR, and this is still the case in amphioxus. During the transition to vertebrates both the invertebrate-type peptide and receptor were lost, leaving only the vertebrate-type system that presently exists.
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Affiliation(s)
- Graeme J Roch
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada.
| | - Ellen R Busby
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada.
| | - Nancy M Sherwood
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada.
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22
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Wang H, Chung-Davidson YW, Li W. Identification and quantification of sea lamprey gonadotropin-releasing hormones by electrospray ionization tandem mass spectrometry. J Chromatogr A 2014; 1345:98-106. [PMID: 24768126 DOI: 10.1016/j.chroma.2014.04.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 10/25/2022]
Abstract
Gonadotropin-releasing hormones (GnRH) are neuropeptide hormones that regulate reproduction in vertebrates. Twenty-five unique chordate GnRH isoforms have been identified, all with very similar molecular architecture. Identification and quantification of endogenous GnRH in biological samples is extremely challenging due to the high levels of sequence similarity among these GnRH peptides and complexity of the biological matrices laden with large numbers of other peptides and protein degradation fragments, and due to low levels of GnRH abundance. In this study, three lamprey GnRH (lGnRH-I, -II, and -III) were extracted from sea lamprey brain tissue and plasma samples by solid-phase extraction (SPE) and identified by a high resolution Q-TOF mass spectrometry (MS). A rapid quantitation method was developed and validated to determine the concentrations of these three lGnRHs by using a UPLC coupled tandem MS in positive ESI multiple reaction monitoring (MRM) mode. Luteinizing hormone-release hormone (LHRH, one of the mammalian GnRHs) was used as the internal standard. The developed quantitation method was fully validated for its recovery, matrix effect, linearity, repeatability, precision and accuracy, and storage stability. This method exhibited excellent linearity in a broad concentration range for all three lGnRHs (R(2)>0.99) and limits of detection (LOD; as low as 0.007 ng/mL). Brain and plasma samples from a total of 280 sea lampreys were analyzed with the developed method to investigate the biological relevance of the lGnRH levels. The concentrations of these three lGnRHs were detected at levels of pictogram per microgram brain tissue and milliliter of plasma. The obtained analytical performance parameters and collected data from real biological samples have proven that this is a robust, sensitive, and fully validated LC-MS/MS method to simultaneously quantify three neuropeptide hormones in complex biological matrices.
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Affiliation(s)
- Huiyong Wang
- Department of Fisheries and Wildlife, Michigan State University, Room 13 Natural Resources Building, 480 Wilson Road, East Lansing, MI 48824, USA
| | - Yu-Wen Chung-Davidson
- Department of Fisheries and Wildlife, Michigan State University, Room 13 Natural Resources Building, 480 Wilson Road, East Lansing, MI 48824, USA
| | - Weiming Li
- Department of Fisheries and Wildlife, Michigan State University, Room 13 Natural Resources Building, 480 Wilson Road, East Lansing, MI 48824, USA.
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Wicks N, Crouch S, Pearl CA. Effects of Improvac and Bopriva on the testicular function of boars ten weeks after immunization. Anim Reprod Sci 2013; 142:149-59. [DOI: 10.1016/j.anireprosci.2013.09.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/11/2013] [Accepted: 09/21/2013] [Indexed: 10/26/2022]
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24
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Stevenson TJ, Hahn TP, MacDougall-Shackleton SA, Ball GF. Gonadotropin-releasing hormone plasticity: a comparative perspective. Front Neuroendocrinol 2012; 33:287-300. [PMID: 23041619 PMCID: PMC3484179 DOI: 10.1016/j.yfrne.2012.09.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 09/04/2012] [Accepted: 09/05/2012] [Indexed: 11/16/2022]
Abstract
Gonadotropin-releasing hormone 1 (GnRH1) is a key regulator of the reproductive neuroendocrine system in vertebrates. Recent developments have suggested that GnRH1 neurons exhibit far greater plasticity at the cellular and molecular levels than previously thought. Furthermore, there is growing evidence that sub-populations of GnRH1 neurons in the preoptic area are highly responsive to specific environmental and hormonal conditions. In this paper we discuss findings that reveal large variation in GnRH1 mRNA and protein expression that are regulated by social cues, photoperiod, and hormonal feedback. We draw upon studies using histochemistry and immediate early genes (e.g., c-FOS/ZENK) to illustrate that specific groups of GnRH1 neurons are topographically organized. Based on data from diverse vertebrate species, we suggest that GnRH1 expression within individuals is temporally dynamic and this plasticity may be evolutionarily conserved. We suggest that the plasticity observed in other neuropeptide systems (i.e. kisspeptin) may have evolved in a similar manner.
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Affiliation(s)
- T J Stevenson
- Institute for Mind and Biology, University of Chicago, Chicago, IL 60637, USA.
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25
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XU YONGJIANG, LIU XUEZHOU, LIAO MEIJIE, WANG HANPING, WANG QINGYIN. Molecular Cloning and Differential Expression of Three GnRH Genes during Ovarian Maturation of Spotted Halibut, Verasper variegatus. ACTA ACUST UNITED AC 2012; 317:434-46. [DOI: 10.1002/jez.1736] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 02/14/2012] [Accepted: 04/03/2012] [Indexed: 11/07/2022]
Affiliation(s)
| | - XUE-ZHOU LIU
- Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao; Shandong; China
| | - MEI-JIE LIAO
- Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao; Shandong; China
| | - HAN-PING WANG
- Aquaculture Genetics and Breeding Laboratory; The Ohio State University South Centers; Piketon; Ohio
| | - QING-YIN WANG
- Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao; Shandong; China
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Nyuji M, Selvaraj S, Kitano H, Ohga H, Yoneda M, Shimizu A, Kaneko K, Yamaguchi A, Matsuyama M. Changes in the expression of pituitary gonadotropin subunits during reproductive cycle of multiple spawning female chub mackerel Scomber japonicus. FISH PHYSIOLOGY AND BIOCHEMISTRY 2012; 38:883-897. [PMID: 22109677 DOI: 10.1007/s10695-011-9576-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Accepted: 11/07/2011] [Indexed: 05/31/2023]
Abstract
The endocrine regulation of reproduction in a multiple spawning fish with an asynchronous-type ovary remains largely unknown. The objectives of this study were to monitor changes in the mRNA expression of three gonadotropin (GtH) subunits (GPα, FSHβ, and LHβ) during the reproductive cycle of the female chub mackerel Scomber japonicus. Cloning and subsequent sequence analysis revealed that the cDNAs of chub mackerel GPα, FSHβ, and LHβ were 658, 535, and 599 nucleotides in length and encoded 117, 115, and 147 amino acids, respectively. We applied a quantitative real-time PCR assay to quantify the mRNA expression levels of these GtH subunits. During the seasonal reproductive cycle, FSHβ mRNA levels remained high during the vitellogenic stages, while GPα and LHβ mRNA levels peaked at the end of vitellogenesis. The expression of all three GtH subunits decreased during the post-spawning period. These results suggest that follicle-stimulating hormone (FSH) is involved in vitellogenesis, while luteinizing hormone (LH) functions during final oocyte maturation (FOM). Both GPα and FSHβ mRNA levels remained high during the FOM stages of the spawning cycle and increased further just after spawning. Thus, FSH synthesis may be strongly activated just after spawning to accelerate vitellogenesis in preparation for the next spawning. Alternatively, LHβ mRNA levels declined during hydration and then increased after ovulation. This study demonstrates that chub mackerel are a good model for investigating GtH functions in multiple spawning fish.
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Affiliation(s)
- Mitsuo Nyuji
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
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Phang YL, Soga T, Kitahashi T, Parhar IS. Cloning and functional expression of novel cholesterol transporters ABCG1 and ABCG4 in gonadotropin-releasing hormone neurons of the tilapia. Neuroscience 2011; 203:39-49. [PMID: 22198513 DOI: 10.1016/j.neuroscience.2011.12.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 12/07/2011] [Accepted: 12/09/2011] [Indexed: 10/14/2022]
Abstract
In addition to reproduction, gonadotropin-releasing hormone (GnRH) has been postulated to control cholesterol metabolism via cholesterol transport, which is carried out partly by the members of ATP-binding cassette (ABC) transporters G1 (ABCG1) and G4 (ABCG4). However, there is yet to be evidence demonstrating the relationship between these transporters with reference to GnRH neurons. In the present study, we cloned two ABCG1 messenger RNA (mRNA) variants and one ABCG4 mRNA and examined their expression in the brain including GnRH neurons (GnRH1, GnRH2, and GnRH3) in the cichlid tilapia (Oreochromis niloticus). Comparison of nucleotide sequences of the tilapia ABCG1 and ABCG4 with that of other fish species showed that both of these genes are evolutionarily conserved among fishes. ABCG1 and ABCG4 were shown to have high mRNA expressions in the CNS, pituitary, and gonads. In the brain, real-time polymerase chain reaction (PCR) showed that ABCG4 mRNA was higher than ABCG1a in all brain regions including the olfactory bulb (ABCG1=13.34, ABCG4=6796.35; P<0.001), dorsal telencephalon (ABCG1=8.64, ABCG4=10149.13; P=0.001), optic tectum (ABCG1=22.12, ABCG4=13931.04; P<0.01), cerebellum (ABCG1=8.68, ABCG4=12382.90; P<0.01), and preoptic area-midbrain-hypothalamus (ABCG1=21.36, ABCG4=13255.41; P=0.001). Similarly, although ABCG1 mRNA level is much higher in the pituitary compared with the brain, it was still significantly lower compared with ABCG4 (ABCG1=337.73, ABCG4=1157.87; P=0.01). The differential pattern of expression of ABCG1 and ABCG4 in the brain versus pituitary suggests that the two transporters are regulated by different mechanisms. Furthermore, ABCG1 and ABCG4 mRNA expressions were found in all three types of laser-captured GnRH neurons with highly similar percentage of expressions, suggesting that cholesterol efflux from GnRH neurons may require heterodimerization of both ABCG1 and ABCG4.
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Affiliation(s)
- Y L Phang
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Sunway Campus, Jalan Lagoon Selatan, Bandar Sunway, 46150 Petaling Jaya, Selangor, Malaysia
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Maruska KP, Fernald RD. Social Regulation of Gene Expression in the Hypothalamic-Pituitary-Gonadal Axis. Physiology (Bethesda) 2011; 26:412-23. [DOI: 10.1152/physiol.00032.2011] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Reproduction is a critically important event in every animals' life and in all vertebrates is controlled by the brain via the hypothalamic-pituitary-gonadal (HPG) axis. In many species, this axis, and hence reproductive fitness, can be profoundly influenced by the social environment. Here, we review how the reception of information in a social context causes genomic changes at each level of the HPG axis.
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Affiliation(s)
- Karen P. Maruska
- Department of Biology, Stanford University, Stanford, California
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Sun B, Tsai PS. A gonadotropin-releasing hormone-like molecule modulates the activity of diverse central neurons in a gastropod mollusk, aplysia californica. Front Endocrinol (Lausanne) 2011; 2:36. [PMID: 22654804 PMCID: PMC3356032 DOI: 10.3389/fendo.2011.00036] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 09/03/2011] [Indexed: 12/05/2022] Open
Abstract
In vertebrates, gonadotropin-releasing hormone (GnRH) is a crucial decapeptide that activates the hypothalamic-pituitary-gonadal axis to ensure successful reproduction. Recently, a GnRH-like molecule has been isolated from a gastropod mollusk, Aplysia californica. This GnRH (ap-GnRH) is deduced to be an undecapeptide, and its function remains to be explored. Our previous study demonstrated that ap-GnRH did not stimulate a range of reproductive parameters. Instead, it affected acute behavioral and locomotive changes unrelated to reproduction. In this study, we used electrophysiology and retrograde tracing to further explore the central role of ap-GnRH. Sharp-electrode intracellular recordings revealed that ap-GnRH had diverse effects on central neurons that ranged from excitatory, inhibitory, to the alteration of membrane potential. Unexpectedly, extracellular recordings revealed that ap-GnRH suppressed the onset of electrical afterdischarge in bag cell neurons, suggesting an inhibitory effect on female reproduction. Lastly, using immunocytochemistry coupled with nickel backfill, we demonstrated that some ap-GnRH neurons projected to efferent nerves known to innervate the foot and parapodia, suggesting ap-GnRH may directly modulate the motor output of these peripheral tissues. Overall, our results suggested that in A. californica, ap-GnRH more likely functioned as a central modulator of complex behavior and motor regulation rather than as a conventional reproductive stimulator.
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Affiliation(s)
- Biao Sun
- Department of Integrative Physiology, University of ColoradoBoulder, CO, USA
| | - Pei-San Tsai
- Department of Integrative Physiology, University of ColoradoBoulder, CO, USA
- *Correspondence: Pei-San Tsai, Department of Integrative Physiology, University of Colorado, 114 Clare Small, Boulder, CO 80309-0354, USA. e-mail:
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Temperature affects brain and pituitary gene expression related to reproduction and growth in the male blue gouramis, Trichogaster trichopterus. ACTA ACUST UNITED AC 2010; 315:203-14. [DOI: 10.1002/jez.663] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 11/17/2010] [Accepted: 11/20/2010] [Indexed: 11/07/2022]
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Ramakrishnan S, Lee W, Navarre S, Kozlowski DJ, Wayne NL. Acquisition of spontaneous electrical activity during embryonic development of gonadotropin-releasing hormone-3 neurons located in the terminal nerve of transgenic zebrafish (Danio rerio). Gen Comp Endocrinol 2010; 168:401-7. [PMID: 20515692 PMCID: PMC2922451 DOI: 10.1016/j.ygcen.2010.05.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 05/23/2010] [Indexed: 11/23/2022]
Abstract
There are multiple populations of gonadotropin-releasing hormone (GnRH) neurons that have distinct physiological and behavioral functions. Teleost fish have a population of GnRH3 neurons located in the terminal nerve (TN) associated with the olfactory bulb that is thought to play a neuromodulatory role in multiple physiological systems, including olfactory, visual, and reproductive. We used transgenic zebrafish in which the GnRH3 promoter drives expression of a green fluorescent protein to identify GnRH3 neurons during development in live embryos. Unlike with hypophysiotropic GnRH neurons of zebrafish, TN-GnRH3 neurons are of neural crest origin and are one of the first populations of GnRH neurons to develop in the early embryo. Using a combination of optical imaging and electrophysiology, we showed that during the first 3 days post-fertilization, TN-GnRH3 neurons increase in number, extend neural projections, move in association with tissue expansion, and acquire an adult-pattern of spontaneous action potential firing. Early during development, about half of the neurons were quiescent/non-firing. Later, at 3 days post-fertilization, there was an increase in the proportion of neurons showing action potential firing and an increase in the number of neurons that showed an adult-like tonic or beating pattern of action potential firing with a firing frequency similar to that seen in adult TN-GnRH3 neurons. This study represents the first neurophysiological investigation of developing GnRH neurons in live embryos--an important advancement in understanding their potential non-reproductive roles during embryogenesis.
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Affiliation(s)
- Siddharth Ramakrishnan
- Department of Physiology, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California 90095
| | - Wenjau Lee
- Department of Physiology, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California 90095
| | - Sammy Navarre
- Institute of Molecular Medicine and Genetics and Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia 30912
| | - David J. Kozlowski
- Institute of Molecular Medicine and Genetics and Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia 30912
| | - Nancy L. Wayne
- Department of Physiology, David Geffen School of Medicine at University of California-Los Angeles, Los Angeles, California 90095
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Trudeau VL, Somoza GM, Natale GS, Pauli B, Wignall J, Jackman P, Doe K, Schueler FW. Hormonal induction of spawning in 4 species of frogs by coinjection with a gonadotropin-releasing hormone agonist and a dopamine antagonist. Reprod Biol Endocrinol 2010; 8:36. [PMID: 20398399 PMCID: PMC2873446 DOI: 10.1186/1477-7827-8-36] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 04/16/2010] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND It is well known that many anurans do not reproduce easily in captivity. Some methods are based on administration of mammalian hormones such as human chorionic gonadotropin, which are not effective in many frogs. There is a need for simple, cost-effective alternative techniques to induce spawning. METHODS Our new method is based on the injection of a combination of a gonadotropin-releasing hormone (GnRH) agonist and a dopamine antagonist. We have named this formulation AMPHIPLEX, which is derived from the combination of the words amphibian and amplexus. This name refers to the specific reproductive behavior of frogs when the male mounts and clasps the female to induce ovulation and to fertilize the eggs as they are laid. RESULTS We describe the use of the method and demonstrate its applicability for captive breeding in 3 different anuran families. We tested several combinations of GnRH agonists with dopamine antagonists using Lithobates pipiens. The combination of des-Gly10, D-Ala6, Pro-LHRH (0.4 microrams/g body weight) and metoclopramide (10 micrograms/g BWt. MET) was most effective. It was used in-season, after short-term captivity and in frogs artificially hibernated under laboratory conditions. The AMPHIPLEX method was also effective in 3 Argentinian frogs, Ceratophrys ornata, Ceratophrys cranwelli and Odontophrynus americanus. CONCLUSION Our approach offers some advantages over other hormonally-based techniques. Both sexes are injected only once and at the same time, reducing handling stress. AMPHIPLEX is a new reproductive management tool for captive breeding in Anura.
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Affiliation(s)
- Vance L Trudeau
- Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ontario K1N 6N5, Canada
| | - Gustavo M Somoza
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (CONICET-UNSAM). Chascomús. Provincia de Buenos Aires, Argentina
| | - Guillermo S Natale
- CIMA, Facultad de Ciencias Exactas, Universidad Nacional La Plata, 47 y 115 (1900), La Plata, Provincia de Buenos Aires, Argentina
| | - Bruce Pauli
- National Wildlife Research Centre, Environment Canada, 1125 Colonel By Drive, Ottawa, Ontario, K1A H3O, Canada
| | - Jacqui Wignall
- Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ontario K1N 6N5, Canada
- National Wildlife Research Centre, Environment Canada, 1125 Colonel By Drive, Ottawa, Ontario, K1A H3O, Canada
| | - Paula Jackman
- Environment Canada, Environmental Science Centre, PO Box 23005, Moncton, New Brunswick, E1A 6S8, Canada
| | - Ken Doe
- Environment Canada, Environmental Science Centre, PO Box 23005, Moncton, New Brunswick, E1A 6S8, Canada
| | - Fredrick W Schueler
- Bishops Mills Natural History Centre, 30 Main Street, Bishops Mills, Ontario, K0G 1T0, Canada
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Selvaraj S, Kitano H, Fujinaga Y, Amano M, Takahashi A, Shimizu A, Yoneda M, Yamaguchi A, Matsuyama M. Immunological characterization and distribution of three GnRH forms in the brain and pituitary gland of chub mackerel (Scomber japonicus). Zoolog Sci 2010; 26:828-39. [PMID: 19968470 DOI: 10.2108/zsj.26.828] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The presence of three gonadotropin-releasing hormone (GnRH) forms in the brain of the chub mackerel, Scomber japonicus, namely, salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II), and seabream GnRH (sbGnRH), was confirmed by combined high performance liquid chromatography (HPLC) and time-resolved fluoroimmunoassay (TR-FIA). Immunocytochemical localization of the three GnRH forms in the brain was Investigated by using specific antisera, to elucidate possible roles of each GnRH form in reproduction in this species, and double immunolabeling was used to localize GnRH-ir (immunoreactive) fibers Innervating the pituitary. sGnRH-ir neurons were localized in the ventral olfactory bulb and terminal nerve ganglion region. Further, sGnRH-ir fibers were found in different regions of the brain, with prominent fibers running in parallel in the preoptic area (POA) without entering the pituitary. cGnRH-II-ir cell bodies were observed only in the midbrain tegmentum region, with a wide distribution of fibers, which were dense in the midbrain tegmentum and spinal cord. SbGnRH-ir cell bodies were localized in the nucleus preopticus of the POA, with fibers in the olfactory bulb, POA, and hypothalamus. Among the three GnRH forms, only SbGnRH-ir fibers innervated the pituitary gland from the preoptic-hypothalamic region, targeting follicle stimulating hormone (FSH) and luteinizing hormone (LH)-producing cells in the proximal pars distalis, as demonstrated by double immunocytochemistry. The localization of the GnRH-ir system was similar in male and female fish. These results demonstrate that multiple GnRH forms exist in the brain of the chub mackerel and suggest that they serve different functions, with SbGnRH having a significant role in reproduction in stimulating FSH- and LH-producing cells, and sGnRH and cGnRH-II serving as neurotransmitters or neuromodulators.
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Affiliation(s)
- Sethu Selvaraj
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
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Palevitch O, Abraham E, Borodovsky N, Levkowitz G, Zohar Y, Gothilf Y. Cxcl12a-Cxcr4b signaling is important for proper development of the forebrain GnRH system in zebrafish. Gen Comp Endocrinol 2010; 165:262-8. [PMID: 19595689 DOI: 10.1016/j.ygcen.2009.07.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2009] [Revised: 06/22/2009] [Accepted: 07/03/2009] [Indexed: 01/09/2023]
Abstract
Hypothalamic gonadotropin-releasing hormone (GnRH) neurons control pituitary gonadotropin secretion and gametogenesis. In the course of development, these neurons migrate from the olfactory placode to the hypothalamus. The precise molecular mechanism of this neuronal migration is unclear. Here, we investigated whether the chemokine receptor, Cxcr4b, and its cognate ligand, Cxcl12a, are required for proper migration of GnRH3 neurons in zebrafish. Deviated GnRH3 axonal projections and neuronal migration were detected in larvae that carry a homozygote cxcr4b mutation. Similarly, knockdown of Cxcr4b or Cxcl12a led to the appearance of abnormal GnRH3 axonal projections and cell migration, including absence of the characteristic lateral crossing of GnRH3 axons at the anterior commissure and optic chiasm. Double-labeling analysis has shown that cxcr4b and cxcl12a are expressed along the GnRH3 migration pathway (i.e. olfactory placode, terminal nerve and the optic chiasm). The results of this study suggest that the Cxcl12a-Cxcr4b ligand-receptor pair are involved in the migration of GnRH3 neurons in zebrafish, and are therefore crucial for the development of this system.
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Affiliation(s)
- Ori Palevitch
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv 69978, Israel.
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Schlosser G. Making senses development of vertebrate cranial placodes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 283:129-234. [PMID: 20801420 DOI: 10.1016/s1937-6448(10)83004-7] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Cranial placodes (which include the adenohypophyseal, olfactory, lens, otic, lateral line, profundal/trigeminal, and epibranchial placodes) give rise to many sense organs and ganglia of the vertebrate head. Recent evidence suggests that all cranial placodes may be developmentally related structures, which originate from a common panplacodal primordium at neural plate stages and use similar regulatory mechanisms to control developmental processes shared between different placodes such as neurogenesis and morphogenetic movements. After providing a brief overview of placodal diversity, the present review summarizes current evidence for the existence of a panplacodal primordium and discusses the central role of transcription factors Six1 and Eya1 in the regulation of processes shared between different placodes. Upstream signaling events and transcription factors involved in early embryonic induction and specification of the panplacodal primordium are discussed next. I then review how individual placodes arise from the panplacodal primordium and present a model of multistep placode induction. Finally, I briefly summarize recent advances concerning how placodal neurons and sensory cells are specified, and how morphogenesis of placodes (including delamination and migration of placode-derived cells and invagination) is controlled.
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Affiliation(s)
- Gerhard Schlosser
- Zoology, School of Natural Sciences & Martin Ryan Institute, National University of Ireland, Galway, Ireland
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36
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Clelland E, Peng C. Endocrine/paracrine control of zebrafish ovarian development. Mol Cell Endocrinol 2009; 312:42-52. [PMID: 19406202 DOI: 10.1016/j.mce.2009.04.009] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 04/16/2009] [Accepted: 04/17/2009] [Indexed: 12/11/2022]
Abstract
Ovarian differentiation and the processes of follicle development, oocyte maturation and ovulation are complex events, requiring the coordinated action of regulatory molecules. In zebrafish, ovarian development is initiated at 10 days after hatching and fish become sexually mature at 3 months. Adult zebrafish have asynchronous ovaries, which contain follicles of all stages of development. Eggs are spawned daily under proper environmental conditions in a population of zebrafish, with individual females spawning irregularly every 4-7 days in mixed sex conditions. Maximal embryo viability is achieved when sexually isolated females are bred in 10-day intervals [Niimi, A.J., LaHam, Q.N., 1974. Influence of breeding time interval on egg number, mortality, and hatching of the zebra fish Brachydanio verio. Can. J. Zool. 52, 515-517]. Similar to other vertebrates, hormones from the hypothalamus-pituitary-gonadal axis play important roles in regulating follicle development. Follicle stimulating hormone (FSH) stimulates estradiol production, which in turn, promotes viteollogenesis. Luteinizing hormone (LH) stimulates the production of 17,20beta-dihydroxy-4-pregnen-3-one (17,20betaP) or maturation inducing hormone (MIH) which acts through membrane progestin receptors to activate maturation promoting factor, leading to oocyte maturation. Recent studies in zebrafish have also provided novel insights into the functions of ovary-derived growth factors in follicle development and oocyte maturation. The present review summarizes the current knowledge on how endocrine and paracrine factors regulate ovarian development in zebrafish. Special emphasis is placed on how follicle development and oocyte maturation in adult females is regulated by gonadotropins, ovarian steroids and growth factors produced by the ovary.
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Affiliation(s)
- Eric Clelland
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
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Differential expression of Gnrh2, Gthβ, and Gthr genes in sterile triploids and fertile tetraploids. Cell Tissue Res 2009; 338:151-9. [DOI: 10.1007/s00441-009-0850-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 07/20/2009] [Indexed: 11/25/2022]
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Zhang D, Xiong H, Mennigen JA, Popesku JT, Marlatt VL, Martyniuk CJ, Crump K, Cossins AR, Xia X, Trudeau VL. Defining global neuroendocrine gene expression patterns associated with reproductive seasonality in fish. PLoS One 2009; 4:e5816. [PMID: 19503831 PMCID: PMC2686097 DOI: 10.1371/journal.pone.0005816] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 05/12/2009] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Many vertebrates, including the goldfish, exhibit seasonal reproductive rhythms, which are a result of interactions between external environmental stimuli and internal endocrine systems in the hypothalamo-pituitary-gonadal axis. While it is long believed that differential expression of neuroendocrine genes contributes to establishing seasonal reproductive rhythms, no systems-level investigation has yet been conducted. METHODOLOGY/PRINCIPAL FINDINGS In the present study, by analyzing multiple female goldfish brain microarray datasets, we have characterized global gene expression patterns for a seasonal cycle. A core set of genes (873 genes) in the hypothalamus were identified to be differentially expressed between May, August and December, which correspond to physiologically distinct stages that are sexually mature (prespawning), sexual regression, and early gonadal redevelopment, respectively. Expression changes of these genes are also shared by another brain region, the telencephalon, as revealed by multivariate analysis. More importantly, by examining one dataset obtained from fish in October who were kept under long-daylength photoperiod (16 h) typical of the springtime breeding season (May), we observed that the expression of identified genes appears regulated by photoperiod, a major factor controlling vertebrate reproductive cyclicity. Gene ontology analysis revealed that hormone genes and genes functionally involved in G-protein coupled receptor signaling pathway and transmission of nerve impulses are significantly enriched in an expression pattern, whose transition is located between prespawning and sexually regressed stages. The existence of seasonal expression patterns was verified for several genes including isotocin, ependymin II, GABA(A) gamma2 receptor, calmodulin, and aromatase b by independent samplings of goldfish brains from six seasonal time points and real-time PCR assays. CONCLUSIONS/SIGNIFICANCE Using both theoretical and experimental strategies, we report for the first time global gene expression patterns throughout a breeding season which may account for dynamic neuroendocrine regulation of seasonal reproductive development.
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Affiliation(s)
- Dapeng Zhang
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Huiling Xiong
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Jan A. Mennigen
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Jason T. Popesku
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Vicki L. Marlatt
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Christopher J. Martyniuk
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Kate Crump
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Andrew R. Cossins
- School of Biological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Xuhua Xia
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Vance L. Trudeau
- Centre for Advanced Research in Environmental Genomics (CAREG), Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
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Xing Y, Nakamura Y, Rainey WE. G protein-coupled receptor expression in the adult and fetal adrenal glands. Mol Cell Endocrinol 2009; 300:43-50. [PMID: 19027826 PMCID: PMC2679220 DOI: 10.1016/j.mce.2008.10.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2008] [Revised: 10/22/2008] [Accepted: 10/22/2008] [Indexed: 10/21/2022]
Abstract
Hormonal regulation of adrenal function occurs primarily through G protein-coupled receptors (GPCR), which may play different roles in fetal vs. adult adrenal glands. In this study, we compared the transcript levels of GPCR between fetal and adult adrenal and found that gonadotropin-releasing hormone receptor (GnRHR), latrophilin 3 receptor, G protein-coupled receptor 37, angiotensin II receptor type 2, latrophilin 2 receptor and melanocortin receptor were expressed at significantly higher levels in fetal adrenal. High GnRHR protein expression was also detected in fetal adrenal using immunohistochemical analysis. To define potential ligand sources for fetal adrenal GnRHR, we demonstrated that GnRH1 mRNA was expressed at high levels in the placenta, while fetal adrenal had high expression of GnRH2. In summary, certain GPCR particularly GnRHR were highly expressed in fetal adrenal and the expression of GnRH mRNA in the placenta and the fetal adrenal raises the possibility of endocrine and/or paracrine/autocrine influences on fetal adrenal function. However, the exact function of GnRHR in fetal adrenal remains to be determined.
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MESH Headings
- Adrenal Glands/cytology
- Adrenal Glands/physiology
- Female
- Fetus/anatomy & histology
- Fetus/physiology
- Gene Expression Regulation, Developmental
- Humans
- Oligonucleotide Array Sequence Analysis
- Pregnancy
- Receptor, Angiotensin, Type 2/genetics
- Receptor, Angiotensin, Type 2/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, LHRH/genetics
- Receptors, LHRH/metabolism
- Receptors, Melanocortin/genetics
- Receptors, Melanocortin/metabolism
- Receptors, Peptide/genetics
- Receptors, Peptide/metabolism
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Affiliation(s)
| | | | - William E. Rainey
- Corresponding author: William E Rainey, Ph.D., Address: Department of Physiology, Medical College of Georgia, 1120 15th Street, CA Building – Room 3094, Augusta, GA 30912, Phone: 706-721-7665, Fax: 706-721-8360,
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40
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Guilgur LG, Strüssmann CA, Somoza GM. mRNA expression of GnRH variants and receptors in the brain, pituitary and ovaries of pejerrey (Odontesthes bonariensis) in relation to the reproductive status. FISH PHYSIOLOGY AND BIOCHEMISTRY 2009; 35:157-166. [PMID: 19189242 DOI: 10.1007/s10695-008-9215-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Accepted: 03/20/2008] [Indexed: 05/27/2023]
Abstract
The present study examined the differential mRNA expression levels of three forms of GnRH (sGnRH, pjGnRH and cGnRH-II) and two forms of GnRH receptor (pjGnRH-R I and pjGnRH-R II) in the brain, pituitary, and ovaries of pejerrey in relation to the reproductive status. The analysis revealed the presence of significant amounts of mRNA of the three GnRH forms while the ovaries showed only two (sGnRH and pjGnRH). The GnRH receptor II was found ubiquitously in the brain, pituitary, and ovaries while the form I was detected only in the brain. The levels of pjGnRH mRNA in the brain and pjGnRH-R II in the pituitary gland varied in correlation with the ovarian condition. However, brain sGnRH and pjGnRH-R I mRNA levels reached a maximum during early stages of ovarian development. In contrast, the brain levels of cGnRH-II mRNA showed no variation. The present study also shows a good correlation of ovarian sGnRH and pjGnRH-R II mRNA levels with the reproductive condition, suggesting that these molecules are may be involved in the regulation of pejerrey ovarian function.
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Affiliation(s)
- L G Guilgur
- Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Chascomús, Buenos Aires, Argentina
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41
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Abstract
The KiSS1/GPR54 system has now been identified in non-mammalian vertebrates. Transcripts encoding for KiSS1 and its receptor, GPR54, have been isolated from a number of fish species. The expression of their genes was characterized in the context of temporal and spatial expression and in response to endocrine manipulations. GPR54 sequence is conserved between mammals and fish, with a second receptor sequence identified in zebrafish. The KiSS1 gene sequence is highly divergent between mammals and fish, yet the human kisspeptin is capable of activating the fish GPR54. As in mammals, the fish KiSS1/GPR54 system appears to be partially regulated by gonadal steroids. The data available for fish are fragmented, yet indicate that the KiSS1/GPR54 system is functionally conserved in non-mammalian vertebrates and supports the notion that it has a role in pubertal development and reproduction in piscine systems.
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Affiliation(s)
- Abigail Elizur
- Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, Maroochydore, Qld., Australia.
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42
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Chambery A, Severino V, D’Aniello A, Parente A. Precursor ion discovery on a hybrid quadrupole–time-of-flight mass spectrometer for gonadotropin-releasing hormone detection in complex biological mixtures. Anal Biochem 2008; 374:335-45. [DOI: 10.1016/j.ab.2007.11.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2007] [Revised: 11/08/2007] [Accepted: 11/12/2007] [Indexed: 11/16/2022]
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43
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Millar RP, Pawson AJ, Morgan K, Rissman EF, Lu ZL. Diversity of actions of GnRHs mediated by ligand-induced selective signaling. Front Neuroendocrinol 2008; 29:17-35. [PMID: 17976709 PMCID: PMC2667102 DOI: 10.1016/j.yfrne.2007.06.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 06/22/2007] [Accepted: 06/26/2007] [Indexed: 12/27/2022]
Abstract
Geoffrey Wingfield Harris' demonstration of hypothalamic hormones regulating pituitary function led to their structural identification and therapeutic utilization in a wide spectrum of diseases. Amongst these, Gonadotropin Releasing Hormone (GnRH) and its analogs are widely employed in modulating gonadotropin and sex steroid secretion to treat infertility, precocious puberty and many hormone-dependent diseases including endometriosis, uterine fibroids and prostatic cancer. While these effects are all mediated via modulation of the pituitary gonadotrope GnRH receptor and the G(q) signaling pathway, it has become increasingly apparent that GnRH regulates many extrapituitary cells in the nervous system and periphery. This review focuses on two such examples, namely GnRH analog effects on reproductive behaviors and GnRH analog effects on the inhibition of cancer cell growth. For both effects the relative activities of a range of GnRH analogs is distinctly different from their effects on the pituitary gonadotrope and different signaling pathways are utilized. As there is only a single functional GnRH receptor type in man we have proposed that the GnRH receptor can assume different conformations which have different selectivity for GnRH analogs and intracellular signaling proteins complexes. This ligand-induced selective-signaling recruits certain pathways while by-passing others and has implications in developing more selective GnRH analogs for highly specific therapeutic intervention.
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Affiliation(s)
- Robert P Millar
- MRC Human Reproductive Sciences Unit, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
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44
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Guilgur LG, Ortí G, Strobl-Mazzulla PH, Fernandino JI, Miranda LA, Somoza GM. Characterization of the cDNAs encoding three GnRH forms in the pejerrey fish Odontesthes bonariensis (Atheriniformes) and the evolution of GnRH precursors. J Mol Evol 2007; 64:614-27. [PMID: 17557168 DOI: 10.1007/s00239-006-0125-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Accepted: 02/12/2007] [Indexed: 01/11/2023]
Abstract
Most vertebrates express two gonadotropin releasing hormone (GnRH) variants in brain tissue but there is an increasing number of fish species for which a third GnRH form has been detected. We characterized the precursors (cDNAs) of all three forms expressed in the brain of the pejerrey (silverside) fish, Odontesthes bonariensis (Atheriniformes): type I (GnRH-I; 440 bp), type II (GnRH-II; 529 bp), and type III (GnRH-III; 515 bp). The expression of these GnRHs precursors was also observed in peripheral tissues related to reproduction (gonads), visual and chemical senses (eye and olfactory epithelium), and osmoregulation (gill), suggesting that in teleost fish and possibly other vertebrates GnRH mediates directly or indirectly many other functions besides reproduction. We also present a comprehensive phylogenetic analysis including representatives of all chordate GnRH precursors characterized to date that supports the idea of two main paralogous GnRH lineages with different function. A "forebrain lineage" separates evolutionarily from the "midbrain lineage" as a result of an ancient duplication (ca. 600 million years ago). A third, fish-only clade of GnRH genes seems to have originated before the divergence of fish and tetrapods but retained only in fish. Phylogenetic analyses of GnRH precursors (DNA and protein sequences) under different optimality criteria converge on this result. Although alternative scenarios could not be statistically rejected in this study due to the relatively short size of the analyzed molecules, this hypothesis also receives support from chromosomal studies of synteny around the GnRH genes in vertebrates.
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Affiliation(s)
- Leonardo G Guilgur
- Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas, Instituto Tecnológico de Chascomús CONICET-UNSAM, C.C. 164 B7130IWA, Chascomús, Provincia de Buenos Aires, Argentina
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45
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Nocillado JN, Levavi-Sivan B, Carrick F, Elizur A. Temporal expression of G-protein-coupled receptor 54 (GPR54), gonadotropin-releasing hormones (GnRH), and dopamine receptor D2 (drd2) in pubertal female grey mullet, Mugil cephalus. Gen Comp Endocrinol 2007; 150:278-87. [PMID: 17083940 DOI: 10.1016/j.ygcen.2006.09.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 09/18/2006] [Accepted: 09/25/2006] [Indexed: 11/16/2022]
Abstract
The G-protein-coupled receptor 54 (muGPR54) cDNA was cloned from the brain of the grey mullet, and its expression level, as well as those of the gonadotropin-releasing hormones (GnRH1, GnRH2, GnRH3) and dopamine receptor D2 (drd2), in the brain, pituitary and ovary of pubertal fish (early, intermediate, advanced) were determined by real-time quantitative RT-PCR (QPCR). The muGPR54 cDNA has an open reading frame of 1140 bp with a predicted 380 amino acid peptide, containing seven putative transmembrane domains and putative N-glycosylation and protein kinase C phosphorylation sites. QPCR results showed that the early stage of puberty in grey mullet is characterized by significantly high levels of expression of GPR54, GnRH and drd2 in the brain relative to the intermediate and advanced stages, except for GnRH1 that increased at the advanced stage of puberty. In the pituitary, drd2 expression declined significantly at the advanced stage relative to levels at the intermediate stage. Ovarian expression of GPR54 significantly increased from the intermediate stage of puberty relative to the early stage while that of GnRH1 acutely increased at the advanced stage of puberty. The ovarian expression of drd2 decreased as puberty progressed, but the changes were not significant. The results suggest the possible role of GPR54 and GnRH in positively regulating pubertal development in grey mullet and the dopaminergic inhibition of reproductive function mediated by drd2.
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Affiliation(s)
- Josephine N Nocillado
- Department of Primary Industries and Fisheries, Bribie Island Aquaculture Research Centre, 144 North Street, Woorim 4507, Qld, Australia
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46
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Wayne NL, Kuwahara K. Beta-endorphin alters electrical activity of gonadotropin releasing hormone neurons located in the terminal nerve of the teleost medaka (Oryzias latipes). Gen Comp Endocrinol 2007; 150:41-7. [PMID: 16919275 DOI: 10.1016/j.ygcen.2006.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Revised: 07/06/2006] [Accepted: 07/07/2006] [Indexed: 01/14/2023]
Abstract
Endogenous opioid peptides (EOPs) are an important class of modulators of the hypothalamo-pituitary axis; treatment with opiates leads to inhibition of GnRH and LH secretion and suppression of reproductive functions. However, little work has been done to investigate the effect of opiates on the electrical activity of GnRH neurons, which ultimately controls GnRH secretion. The purpose of the present study was to investigate the effects of the EOP beta-endorphin on electrical activity of GnRH neurons located in the terminal nerve (TN) associated with the olfactory bulb. We used an excised intact brain preparation from transgenic medaka in which green fluorescent protein (GFP) is genetically expressed in TN-GnRH neurons. These GFP-expressing neurons were then targeted for whole-cell current clamp recordings. Treatment with beta-endorphin led to changes in several characteristics of electrical activity, including depolarization of membrane potential and a decrease in spike amplitude--similar to that observed in response to depolarizing high K(+) treatment. This finding suggests a model in which beta-endorphin depolarizes membrane potential leading to Na(+)-channel inactivation, and subsequent suppression of action-potential amplitude. On the other hand, beta-endorphin had no effect on membrane potential in synaptically isolated GnRH neurons. These results suggest that beta-endorphin is acting indirectly on TN-GnRH neurons to inhibit action potential firing.
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Affiliation(s)
- Nancy L Wayne
- Department of Physiology, University of California at Los Angeles School of Medicine, Los Angeles, CA 90095, USA.
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47
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Maruska KP, Mizobe MH, Tricas TC. Sex and seasonal co-variation of arginine vasotocin (AVT) and gonadotropin-releasing hormone (GnRH) neurons in the brain of the halfspotted goby. Comp Biochem Physiol A Mol Integr Physiol 2006; 147:129-44. [PMID: 17276115 DOI: 10.1016/j.cbpa.2006.12.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 12/04/2006] [Accepted: 12/05/2006] [Indexed: 10/23/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) and arginine vasotocin (AVT) are critical regulators of reproductive behaviors that exhibit tremendous plasticity, but co-variation in discrete GnRH and AVT neuron populations among sex and season are only partially described in fishes. We used immunocytochemistry to examine sexual and temporal variations in neuron number and size in three GnRH and AVT cell groups in relation to reproductive activities in the halfspotted goby (Asterropteryx semipunctata). GnRH-immunoreactive (-ir) somata occur in the terminal nerve, preoptic area, and midbrain tegmentum, and AVT-ir somata within parvocellular, magnocellular, and gigantocellular regions of the preoptic area. Sex differences were found among all GnRH and AVT cell groups, but were time-period dependent. Seasonal variations also occurred in all GnRH and AVT cell groups, with coincident elevations most prominent in females during the peak- and non-spawning periods. Sex and temporal variability in neuropeptide-containing neurons are correlated with the goby's seasonally-transient reproductive physiology, social interactions, territoriality and parental care. Morphological examination of GnRH and AVT neuron subgroups within a single time period provides detailed information on their activities among sexes, whereas seasonal comparisons provide a fine temporal sequence to interpret the proximate control of reproduction and the evolution of social behavior.
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Affiliation(s)
- Karen P Maruska
- Department of Zoology, University of Hawai'i at Manoa, 2538 The Mall, Honolulu, HI 96822, USA.
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48
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Quintanar JL, Salinas E, González R. Expression of gonadotropin-releasing hormone receptor in cerebral cortical neurons of embryos and adult rats. Neurosci Lett 2006; 411:22-5. [PMID: 17110036 DOI: 10.1016/j.neulet.2006.06.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 06/24/2006] [Accepted: 06/28/2006] [Indexed: 11/27/2022]
Abstract
Mammalian gonadotropin-releasing hormone (GnRH) was initially isolated from hypothalamus and its receptor from anterior pituitary, although extrapituitary GnRH receptors have been reported. The aim of the present study was to investigate whether GnRH receptor and its mRNA are expressed in cerebral cortical neurons of rat embryos and adult rats using immunohistochemical and reverse transcriptase polymerase chain reaction (RT-PCR) techniques. The immunohistochemistry and RT-PCR analysis showed expression of GnRH receptor and presence of its mRNA, in both cerebral cortical neurons of rat embryos and cerebral cortical tissues of adult rats. Additional experiments showed a decrease in the receptor mRNA expression when cultured neurons of rat embryos were treated with GnRH. It is possible that the presence of GnRH receptors in cortical neurons of rat may be involved in other physiological roles such as neurohormone or neuromodulator.
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Affiliation(s)
- J Luis Quintanar
- Laboratory of Neurophysiology, Department of Physiology and Pharmacology, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940 C.P. 20100, Col. Ciudad Universitaria, Aguascalientes Ags, Mexico.
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49
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Palevitch O, Kight K, Abraham E, Wray S, Zohar Y, Gothilf Y. Ontogeny of the GnRH systems in zebrafish brain: in situ hybridization and promoter-reporter expression analyses in intact animals. Cell Tissue Res 2006; 327:313-22. [PMID: 17036230 DOI: 10.1007/s00441-006-0279-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Accepted: 06/09/2006] [Indexed: 10/24/2022]
Abstract
The ontogeny of two gonadotropin-releasing-hormone (GnRH) systems, salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II), was investigated in zebrafish (Danio rerio). In situ hybridization (ISH) first detected sGnRH mRNA-expressing cells at 1 day post-fertilization (pf) anterior to the developing olfactory organs. Subsequently, cells were seen along the ventral olfactory organs and the olfactory bulbs, reaching the terminal nerve (TN) ganglion at 5-6 days pf. Some cells were detected passing posteriorly through the ventral telencephalon (10-25 days pf), and by 25-30 days pf, sGnRH cells were found in the hypothalamic/preoptic area. Continuous documentation in live zebrafish was achieved by a promoter-reporter expression system. The expression of enhanced green fluorescent protein (EGFP) driven by the sGnRH promoter allowed the earlier detection of cells and projections and the migration of sGnRH neurons. This expression system revealed that long leading processes, presumably axons, preceded the migration of the sGnRH neuron somata. cGnRH-II mRNA expressing cells were initially detected (1 day pf) by ISH analysis at lateral aspects of the midbrain and later on (starting at 5 days pf) at the midline of the midbrain tegmentum. Detection of red fluorescent protein (DsRed) driven by the cGnRH-II promoter confirmed the midbrain expression domain and identified specific hindbrain and forebrain cGnRH-II-cells that were not identified by ISH. The forebrain DsRed-expressing cells seemed to emerge from the same site as the sGnRH-EGFP-expressing cells, as revealed by co-injection of both constructs. These studies indicate that zebrafish TN and hypothalamic sGnRH cell populations share a common embryonic origin and migratory path, and that midbrain cGnRH-II cells originate within the midbrain.
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Affiliation(s)
- Ori Palevitch
- Department of Zoology, George S Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
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50
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Whitlock KE, Illing N, Brideau NJ, Smith KM, Twomey S. Development of GnRH cells: Setting the stage for puberty. Mol Cell Endocrinol 2006; 254-255:39-50. [PMID: 16777316 DOI: 10.1016/j.mce.2006.04.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Cells containing gonadotropin-releasing hormone (GnRH) are essential not only for reproduction but also for neuromodulatory functions in the adult animal. A variety of studies have hinted at multiple origins for GnRH-containing cells in the developing embryo. We have shown, using zebrafish as a model system, that GnRH cells originate from precursors lying outside the olfactory placode: the region of the anterior pituitary gives rise to hypothalamic GnRH cells and the cranial neural crest gives rise to the GnRH cells of the terminal nerve and midbrain. Cells of both the forming anterior pituitary and cranial neural crest are closely apposed to the precursors of the olfactory epithelium during early development. Disruption of kallmann gene function results in loss of the hypothalamic but not the terminal nerve GnRH cells during early development. The GnRH proteins are expressed early in development and this expression is mirrored by the onset of GnRH receptor (GnRH-R) expression during early development. Thus the signaling of the GnRH neuronal circuitry is set up early in development laying the foundation for the GnRH network that is activated at puberty leading to reproductive function in the mature animal.
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Affiliation(s)
- K E Whitlock
- Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY 14853, United States.
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