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Xu J, Hou F, Wang D, Li J, Yang G. Characterization and expression of melanin-concentrating hormone (MCH) in common carp (Cyprinus carpio) during fasting and reproductive cycle. FISH PHYSIOLOGY AND BIOCHEMISTRY 2019; 45:805-817. [PMID: 30426273 DOI: 10.1007/s10695-018-0586-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 10/31/2018] [Indexed: 06/09/2023]
Abstract
Melanin-concentrating hormone (MCH) was initially known as a regulator of teleost skin color and possesses multiple functions in mammals, such as the regulation of energy balance and reproduction. However, the role of MCH in fish remains unclear. In the present study, a 590 bp cDNA fragment of common carp (Cyprinus carpio) MCH gene was cloned. Amino acid sequence similarities with other teleost ranged from 23 to 93%. The mature MCH peptide (DTMRCMVGRVYRPCWEV) located in the C-terminal region of MCH precursor was 100% identical to that of goldfish, zebrafish, chum salmon, and rainbow trout. Tissue expression profiles showed that MCH mRNA was ubiquitously expressed throughout the brain and peripheral tissues and highly expressed in the brain and pituitary. Within the brain, MCH mRNA was expressed preponderantly in the hypothalamus. MCH mRNA expression in the hypothalamus was increased after feeding, decreased after 3, 5, or 7 days fasting, and increased upon refeeding. These results suggested that MCH might have anorexigenic actions in common carp. Meanwhile, MCH gene expression varied based on reproductive cycle, which might be related to the long-term regulation of MCH in energy balance. In conclusion, our novel finding revealed that MCH was involved in the regulation of appetite and energy balance in common carp.
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Affiliation(s)
- Jing Xu
- College of Pharmacy, South Central University for Nationalities, Wuhan, 430074, China
| | - Fuyuan Hou
- College of Pharmacy, South Central University for Nationalities, Wuhan, 430074, China
| | - Debin Wang
- College of Pharmacy, South Central University for Nationalities, Wuhan, 430074, China
| | - Jun Li
- College of Pharmacy, South Central University for Nationalities, Wuhan, 430074, China
| | - Guangzhong Yang
- College of Pharmacy, South Central University for Nationalities, Wuhan, 430074, China.
- National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan, 430074, People's Republic of China.
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2
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Bertolesi GE, Zhang JZ, McFarlane S. Plasticity for colour adaptation in vertebrates explained by the evolution of the genes pomc, pmch and pmchl. Pigment Cell Melanoma Res 2019; 32:510-527. [PMID: 30791235 PMCID: PMC7167667 DOI: 10.1111/pcmr.12776] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 01/27/2019] [Accepted: 02/16/2019] [Indexed: 02/06/2023]
Abstract
Different camouflages work best with some background matching colour. Our understanding of the evolution of skin colour is based mainly on the genetics of pigmentation ("background matching"), with little known about the evolution of the neuroendocrine systems that facilitate "background adaptation" through colour phenotypic plasticity. To address the latter, we studied the evolution in vertebrates of three genes, pomc, pmch and pmchl, that code for α-MSH and two melanin-concentrating hormones (MCH and MCHL). These hormones induce either dispersion/aggregation or the synthesis of pigments. We find that α-MSH is highly conserved during evolution, as is its role in dispersing/synthesizing pigments. Also conserved is the three-exon pmch gene that encodes MCH, which participates in feeding behaviours. In contrast, pmchl (known previously as pmch), is a teleost-specific intron-less gene. Our data indicate that in zebrafish, pmchl-expressing neurons extend axons to the pituitary, supportive of an MCHL hormonal role, whereas zebrafish and Xenopus pmch+ neurons send axons dorsally in the brain. The evolution of these genes and acquisition of hormonal status for MCHL explain different mechanisms used by vertebrates to background-adapt.
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Affiliation(s)
- Gabriel E Bertolesi
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - John Zhijia Zhang
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sarah McFarlane
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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3
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Delgado MJ, Cerdá-Reverter JM, Soengas JL. Hypothalamic Integration of Metabolic, Endocrine, and Circadian Signals in Fish: Involvement in the Control of Food Intake. Front Neurosci 2017; 11:354. [PMID: 28694769 PMCID: PMC5483453 DOI: 10.3389/fnins.2017.00354] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 06/07/2017] [Indexed: 12/12/2022] Open
Abstract
The regulation of food intake in fish is a complex process carried out through several different mechanisms in the central nervous system (CNS) with hypothalamus being the main regulatory center. As in mammals, a complex hypothalamic circuit including two populations of neurons: one co-expressing neuropeptide Y (NPY) and Agouti-related peptide (AgRP) and the second one population co-expressing pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) is involved in the integration of information relating to food intake control. The production and release of these peptides control food intake, and the production results from the integration of information of different nature such as levels of nutrients and hormones as well as circadian signals. The present review summarizes the knowledge and recent findings about the presence and functioning of these mechanisms in fish and their differences vs. the known mammalian model.
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Affiliation(s)
- María J. Delgado
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de MadridMadrid, Spain
| | - José M. Cerdá-Reverter
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones CientíficasCastellón, Spain
| | - José L. Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de VigoVigo, Spain
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4
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Wang T, Yuan D, Zhou C, Lin F, Wei R, Chen H, Wu H, Xin Z, Liu J, Gao Y, Chen D, Yang S, Wang Y, Pu Y, Li Z. Molecular characterization of melanin-concentrating hormone (MCH) in Schizothorax prenanti: cloning, tissue distribution and role in food intake regulation. FISH PHYSIOLOGY AND BIOCHEMISTRY 2016; 42:883-893. [PMID: 26690629 DOI: 10.1007/s10695-015-0182-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 12/11/2015] [Indexed: 06/05/2023]
Abstract
Melanin-concentrating hormone (MCH) is a crucial neuropeptide involved in various biological functions in both mammals and fish. In this study, the full-length MCH cDNA was obtained from Schizothorax prenanti by rapid amplification of cDNA ends polymerase chain reaction. The full-length MCH cDNA contained 589 nucleotides including an open reading frame of 375 nucleotides encoding 256 amino acids. MCH mRNA was highly expressed in the brain by real-time quantitative PCR analysis. Within the brain, expression of MCH mRNA was preponderantly detected in the hypothalamus. In addition, the MCH mRNA expression in the S. prenanti hypothalamus of fed group was significantly decreased compared with the fasted group at 1 and 3 h post-feeding, respectively. Furthermore, the MCH gene expression presented significant increase in the hypothalamus of fasted group compared with the fed group during long-term fasting. After re-feeding, there was a dramatic decrease in MCH mRNA expression in the hypothalamus of S. prenanti. The results indicate that the expression of MCH is affected by feeding status. Taken together, our results suggest that MCH may be involved in food intake regulation in S. prenanti.
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Affiliation(s)
- Tao Wang
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Dengyue Yuan
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Chaowei Zhou
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Fangjun Lin
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Rongbin Wei
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Hu Chen
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Hongwei Wu
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Zhiming Xin
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Ju Liu
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Yundi Gao
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Defang Chen
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Shiyong Yang
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Yan Wang
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Yundan Pu
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China
| | - Zhiqiong Li
- Department of Aquaculture, Sichuan Agricultural University, 46# Xinkang Road, Ya'an, China.
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Mella-Alvarado V, Gautier A, Le Gac F, Lareyre JJ. Tissue and cell-specific transcriptional activity of the human cytomegalovirus immediate early gene promoter (UL123) in zebrafish. Gene Expr Patterns 2013; 13:91-103. [PMID: 23347918 DOI: 10.1016/j.gep.2013.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 12/27/2012] [Accepted: 01/03/2013] [Indexed: 10/27/2022]
Abstract
The human cytomegalovirus (CMV) is a member of the herpesvirus superfamily and causes different diseases including encephalitis, gastrointestinal diseases, pneumonitis, hepatitis, and retinitis. The immediate early (IE) gene of the human cytomegalovirus is essential to the viral replication. The proximal promoter region of this gene behaves as a strong enhancer and was commonly used to overexpress genes in vitro and in vivo in numerous cell types and species. However, there was no detailed report on the spatial and temporal transcriptional activity of the human CMV-IE gene promoter in zebrafish. In the present study, we generated stable transgenic zebrafish lines carrying the eGFP reporter gene under the control of the human CMV-IE gene promoter (-602/-14). We demonstrated that the hCMV-IE:eGFP transgene was expressed in numerous tissues but transgene expression was either regionalized or restricted to specific cell types as embryo and larval development progressed. In adult, the global expression pattern was similar but not identical to that described for the simian CMV-IE gene promoter in stable zebrafish with high transgene expression in the spinal cord, olfactory organs, central nervous system, neuromasts, retina, and skeletal muscles. However, we describe additional major expression sites in the hepatocytes, the epithelial cells of the intestine, the epithelial cells of the renal tubules, and the oocytes. Interestingly, our study shows that the tissue and cell specific expression pattern of the human CMV-IE gene promoter is rather well conserved in stable transgenic zebrafish compared to that observed in mouse. The major expression sites described in zebrafish are in agreement with the targeted cells and symptoms resulting from CMV infections in human. Finally, the hCMV:eGFP transgenic lines described in the present study will be valuable tools to trace specific cell lineages in adult zebrafish.
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Affiliation(s)
- Vanessa Mella-Alvarado
- INRA, UR1037 LPGP (Laboratoire de Physiologie et Génomique des Poissons), SFR BIOSIT, BioGenOuest, Campus de Beaulieu, 35042 Rennes cedex, France
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6
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Tao YX, Yuan ZH, Xie J. G Protein-Coupled Receptors as Regulators of Energy Homeostasis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:1-43. [DOI: 10.1016/b978-0-12-386933-3.00001-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Hoskins LJ, Volkoff H. The comparative endocrinology of feeding in fish: insights and challenges. Gen Comp Endocrinol 2012; 176:327-35. [PMID: 22226758 DOI: 10.1016/j.ygcen.2011.12.025] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 12/17/2011] [Accepted: 12/19/2011] [Indexed: 12/28/2022]
Abstract
Studying the endocrine regulation of food intake in fish can be challenging due to the diversity in appetite-regulating hormones and the diversity within the fish group itself. Studies show that although the structure of the hormones is relatively conserved among vertebrates, their functions might vary between fish and mammals as well as among fish species. In addition, feeding behavior and the action of appetite regulators can be largely modulated by the feeding and reproductive status of the fish as well as the environment in which they evolve. This review gives a brief perspective of the endocrine regulation of feeding in fish, some of the methods used, and challenges encountered when using a comparative approach.
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Affiliation(s)
- Leah J Hoskins
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada A1B 3X9
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8
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Pérez Sirkin DI, Cánepa MM, Fossati M, Fernandino JI, Delgadin T, Canosa LF, Somoza GM, Vissio PG. Melanin concentrating hormone (MCH) is involved in the regulation of growth hormone in Cichlasoma dimerus (Cichlidae, Teleostei). Gen Comp Endocrinol 2012; 176:102-11. [PMID: 22266076 DOI: 10.1016/j.ygcen.2012.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 12/13/2011] [Accepted: 01/03/2012] [Indexed: 01/05/2023]
Abstract
Growth hormone (GH) is the main pituitary hormone involved in somatic growth. In fish, the neuroendocrine control of GH is multifactorial due to the interaction of multiple inhibitors and stimulators. Melanin-concentrating hormone (MCH) is a cyclic peptide involved in skin color regulation of fish. In addition, MCH has been related to the regulation of food intake in both mammals and fish. There is only one report presenting evidences on the GH release stimulation by MCH in mammals in experiments in vitro, but there are no data on non-mammals. In the present work, we report for the first time the sequence of MCH and GH cDNA in Cichlasoma dimerus, a freshwater South American cichlid fish. We detected contacts between MCH fibers and GH cells in the proximal pars distalis region of the pituitary gland by double label confocal immunofluorescence indicating a possible functional relationship. Besides, we found that MCH increased GH transcript levels and stimulated GH release in pituitary cultures. Additionally, C. dimerus exposed to a white background had a greater number of MCH neurons with a larger nuclear area and higher levels of MCH transcript than those fish exposed to a black background. Furthermore, fish reared for 3 months in a white background showed a greater body weight and total length compared to those from black background suggesting that MCH might be related to somatic growth in C. dimerus. Our results report for the first time, that MCH is involved in the regulation of the synthesis and release of GH in vitro in C. dimerus, and probably in the fish growth rate.
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Affiliation(s)
- D I Pérez Sirkin
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA Buenos Aires, Argentina
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9
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Hamamoto A, Mizusawa K, Takahashi A, Saito Y. Signalling pathway of goldfish melanin-concentrating hormone receptors 1 and 2. ACTA ACUST UNITED AC 2011; 169:6-12. [PMID: 21539863 DOI: 10.1016/j.regpep.2011.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 04/14/2011] [Indexed: 10/18/2022]
Abstract
Melanin-concentrating hormone (MCH) is the natural ligand for the MCH-1 receptor (MCHR1) and MCH-2 receptor (MCHR2). The MCH-MCHR1 system plays a central role in energy metabolism in rodents. Recently, we identified MCHR1 and MCHR2 orthologues in goldfish, designated gfMCHR1 and gfMCHR2. In a mammalian cell-based assay, calcium mobilization was evoked by gfMCHR2 via both Gαi/o and Gαq, while the gfMCHR1-mediated response was exclusively dependent on Gαq. This coupling capacity to G proteins is in contrast to human MCHR1 and MCHR2. Here, we extended our previous characterization of the two gfMCHRs by examining their different signalling pathway. We found that MCH caused activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) via both gfMCHR1 and gfMCHR2 in dose-dependent manners. Unlike the case for gfMCHR2, gfMCHR1 signalling was not sensitive to pertussis toxin, suggesting Gαq coupling of gfMCHR1 in the ERK1/2 pathway as well as a calcium mobilization system. Cyclic AMP assays revealed that gfMCHR2 was efficiently coupled to Gαi/o, while gfMCHR1 was weakly coupled to Gαs. Finally, we investigated the transduction features stimulated by two mammalian MCH analogues. As expected, Compound 15, which is a full agonist of human MCHR1, was a potent gfMCHR1 agonist in multiple signalling pathways. On the other hand, Compound 30, which is a human MCHR1-selective antagonist with negligible agonist potency, unexpectedly acted as a selective agonist of gfMCHR1. These results are the first to demonstrate that gfMCHR1 and gfMCHR2 have quite different signalling properties from human MCHRs.
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Affiliation(s)
- Akie Hamamoto
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8521, Japan
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10
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Volkoff H, Hoskins LJ, Tuziak SM. Influence of intrinsic signals and environmental cues on the endocrine control of feeding in fish: potential application in aquaculture. Gen Comp Endocrinol 2010; 167:352-9. [PMID: 19735660 DOI: 10.1016/j.ygcen.2009.09.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Revised: 08/30/2009] [Accepted: 09/02/2009] [Indexed: 01/05/2023]
Abstract
Optimization of food consumption and ultimately growth are major concerns for aquaculture. In fish, food intake is regulated by several hormones produced by both brain and peripheral tissues. Changes in feeding behavior and appetite usually occur through the modulation of the gene expression and/or action of these appetite-regulating hormones and can be due not only to variations in intrinsic factors such as nutritional/metabolic or reproductive status, but also to changes in environmental factors, such as temperature and photoperiod. In addition, the gene expression and/or plasma levels of appetite-regulating hormones might also display daily as well as circannual (seasonal) rhythms. Despite recent advances, our current understanding of the regulation of feeding in fish is still limited. We give here a brief overview of our current knowledge of the endocrine regulation of feeding in fish and describe how a better understanding of appetite-related hormones in fish might lead to the development of sustainable aquaculture.
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Affiliation(s)
- Hélène Volkoff
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada.
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11
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Berman JR, Skariah G, Maro GS, Mignot E, Mourrain P. Characterization of two melanin-concentrating hormone genes in zebrafish reveals evolutionary and physiological links with the mammalian MCH system. J Comp Neurol 2010; 517:695-710. [PMID: 19827161 DOI: 10.1002/cne.22171] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Melanin-concentrating hormone (MCH) regulates feeding and complex behaviors in mammals and pigmentation in fish. The relationship between fish and mammalian MCH systems is not well understood. Here, we identify and characterize two MCH genes in zebrafish, Pmch1 and Pmch2. Whereas Pmch1 and its corresponding MCH1 peptide resemble MCH found in other fish, the zebrafish Pmch2 gene and MCH2 peptide share genomic structure, synteny, and high peptide sequence homology with mammalian MCH. Zebrafish Pmch genes are expressed in closely associated but non-overlapping neurons within the hypothalamus, and MCH2 neurons send numerous projections to multiple MCH receptor-rich targets with presumed roles in sensory perception, learning and memory, arousal, and homeostatic regulation. Preliminary functional analysis showed that whereas changes in zebrafish Pmch1 expression correlate with pigmentation changes, the number of MCH2-expressing neurons increases in response to chronic food deprivation. These findings demonstrate that zebrafish MCH2 is the putative structural and functional ortholog of mammalian MCH and help elucidate the nature of MCH evolution among vertebrates.
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Affiliation(s)
- Jennifer R Berman
- Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto, California 94304, USA
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12
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Matsuda K, Kojima K, Shimakura SI, Takahashi A. Regulation of food intake by melanin-concentrating hormone in goldfish. Peptides 2009; 30:2060-5. [PMID: 19836661 DOI: 10.1016/j.peptides.2009.02.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 02/23/2009] [Accepted: 02/24/2009] [Indexed: 01/24/2023]
Abstract
Melanin-concentrating hormone (MCH), originally discovered in the teleost pituitary, is a hypothalamic neuropeptide involved in the regulation of body color in fish. Although MCH is also present in the mammalian brain, it has no evident function in providing pigmentation. Instead, this peptide is now recognized to be one of the key neuropeptides that act as appetite enhancers in mammals such as rodents and primates. Although there has been little information about the central action of MCH on appetite in fish, recent studies have indicated that, in goldfish, MCH acts as an anorexigenic neuropeptide, modulating the alpha-melanocyte-stimulating hormone signaling pathway through neuronal interaction. These observations indicate that there may be major differences in the mode of action of MCH between fish and mammals. This paper reviews what is currently known about the regulation of food intake by MCH in fish, especially the goldfish.
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13
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Iwai T, Inoue S, Kotani T, Yamashita M. Production of transgenic medaka fish carrying fluorescent nuclei and chromosomes. Zoolog Sci 2009; 26:9-16. [PMID: 19267607 DOI: 10.2108/zsj.26.9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As with zebrafish, attention has focused on the teleost medaka Oryzias latipes as an experimental animal representative of non-mammalian vertebrates in various fields of biological science. To enable real-time analyses of the dynamics of nuclei and chromosomes in living medaka cells, we produced a transgenic medaka expressing a fusion protein between histone H2B and green fluorescent protein (GFP) under the control of a cytomegalovirus (CMV) promoter. Since the nuclei and chromosomes of transgenic medaka cells are labeled with GFP, their morphological changes can be instantly monitored throughout the mitotic cell cycle progression under a fluorescent microscope without any fixation and staining of samples. However, GFP-labeling of nuclei and chromosomes is not successful during early embryonic development until zygotic expression begins and during the meiotic cell cycle progression, because the CMV promoter does not work in these stages. In addition, histone H2B-GFP fusion proteins are expressed in an organ-specific manner; strong and ubiquitous expression occurs in cells comprising the gut and fin, whereas the expression is restricted to certain types of cells in the liver and brain. These findings suggest that the CMV-driven expression of the histone H2B-GFP transgene is modified depending on the integration site of the transgene in the genome. Nevertheless, easy and precise monitoring of cytological changes in nuclei and chromosomes in the majority of mitotic cells by using the transgenic medaka will greatly contribute to a better understanding of control mechanisms of nuclear and chromosomal behaviors in vertebrate cells.
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Affiliation(s)
- Toshiharu Iwai
- Laboratory of Reproductive and Developmental Biology, Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
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14
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15
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Takei Y. Exploring novel hormones essential for seawater adaptation in teleost fish. Gen Comp Endocrinol 2008; 157:3-13. [PMID: 18452919 DOI: 10.1016/j.ygcen.2008.03.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 03/11/2008] [Accepted: 03/12/2008] [Indexed: 12/29/2022]
Abstract
Marine fish are dehydrated in hyperosmotic seawater (SW), but maintain water balance by drinking surrounding SW if they are capable of excreting the excess ions, particularly Na(+) and Cl(-), absorbed with water by the intestine. An integrative approach is essential for understanding the mechanisms for SW adaptation, in which hormones play pivotal roles. Comparative genomic analyses have shown that hormones that have Na(+)-extruding and vasodepressor properties are greatly diversified in teleost fish. Physiological studies at molecular to organismal levels have revealed that these diversified hormones are much more potent and efficacious in teleost fish than in mammals and are important for survival in SW and for maintenance of low arterial pressure in a gravity-free aquatic environment. This is typified by the natriuretic peptide (NP) family, which is diversified into seven members (ANP, BNP, VNP and CNP1, 2, 3 and 4) and exerts potent hyponatremic and vasodepressor actions in marine fish. Another example is the guanylin family, which consists of three paralogs (guanylin, uroguanylin and renoguanylin), and stimulates Cl(-) secretion into the intestinal lumen and activates the absorptive-type Na-K-2Cl cotransporter by local luminocrine actions. The most recent addition is the adrenomedullin (AM) family, which has five members (AM1, 2, 3, 4 and 5), with AM2 and AM5 showing the most potent or efficacious vasodepressor and osmoregulatory effects among known hormones in teleost fish. Accumulating evidence strongly indicates that members of these diversified hormone families play essential roles in SW adaptation in teleost fish. In this short review, the author has attempted to propose a novel approach for identification of new hormones that are important for SW adaptation using comparative genomic and functional studies. The author has also suggested potential hormone families that are diversified in teleost fish and appear to be involved in SW adaptation through their ion-extruding actions.
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Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Ocean Research Institute, The University of Tokyo, 1-15-1 Minamidai, Nakano, Tokyo 164-8639, Japan.
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16
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Pissios P, Bradley RL, Maratos-Flier E. Expanding the scales: The multiple roles of MCH in regulating energy balance and other biological functions. Endocr Rev 2006; 27:606-20. [PMID: 16788162 DOI: 10.1210/er.2006-0021] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Melanin-concentrating hormone (MCH) is a cyclic peptide originally identified as a 17-amino-acid circulating hormone in teleost fish, where it is secreted by the pituitary in response to stress and environmental stimuli. In fish, MCH lightens skin color by stimulating aggregation of melanosomes, pigment-containing granules in melanophores, cells of neuroectodermal origin found in fish scales. Although the peptide structure between fish and mammals is highly conserved, in mammals, MCH has no demonstrable effects on pigmentation; instead, based on a series of pharmacological and genetic experiments, MCH has emerged as a critical hypothalamic regulator of energy homeostasis, having effects on both feeding behavior and energy expenditure.
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Affiliation(s)
- Pavlos Pissios
- Division of Endocrinology, Department of Medicine, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, Massachusetts 02215, USA
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Matsuda K, Shimakura SI, Maruyama K, Miura T, Uchiyama M, Kawauchi H, Shioda S, Takahashi A. Central administration of melanin-concentrating hormone (MCH) suppresses food intake, but not locomotor activity, in the goldfish, Carassius auratus. Neurosci Lett 2006; 399:259-63. [PMID: 16503089 DOI: 10.1016/j.neulet.2006.02.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2006] [Revised: 02/03/2006] [Accepted: 02/03/2006] [Indexed: 11/23/2022]
Abstract
Melanin-concentrating hormone (MCH) is a hypothalamo-pituitary peptide, which was first identified in the salmon pituitary as a hormone affecting body color. Recently, MCH has been implicated in the regulation of feeding behavior and energy homeostasis in mammals. Despite a growing body of knowledge concerning MCH in mammals, however, there is little information about the effect of MCH on appetite and behavior in fish. The aim of the present study was to investigate the action of MCH on feeding behavior and spontaneous locomotor activity in the goldfish. We administered synthetic MCH by intracerebroventricular (ICV) injection and examined its effect on food intake and locomotor activity using an automatic monitoring system. Both types of synthetic MCH we employed, which are of fish and human origin, were effective in stimulating aggregation of melanin granules in the melanophores of goldfish scales. Cumulative food intake was significantly decreased by ICV injection of both MCHs in a dose-dependent manner. ICV injection of fish MCH at the same doses as those used for examination of food intake induced no marked changes in locomotor activity during the observation period. These results suggest that MCH influences feeding behavior, but not spontaneous locomotor activity, in the goldfish, and may exert an anorexigenic action in the goldfish brain, unlike its orexigenic action in mammals.
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Affiliation(s)
- Kouhei Matsuda
- Laboratory of Regulatory Biology, Graduate School of Science and Engineering, University of Toyama, 3190-Gofuku, Toyama 930-8555, Japan.
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Cerdá-Reverter JM, Canosa LF, Peter RE. Regulation of the hypothalamic melanin-concentrating hormone neurons by sex steroids in the goldfish: possible role in the modulation of luteinizing hormone secretion. Neuroendocrinology 2006; 84:364-77. [PMID: 17192703 DOI: 10.1159/000098334] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Accepted: 11/16/2006] [Indexed: 11/19/2022]
Abstract
In teleost fish, melanin-concentrating hormone (MCH) is a cyclic heptadecapeptide released from the pituitary during white background adaptation. In the periphery MCH concentrates melanin granules in melanophores thus lightening the body color of fish. Evidence from mammalian studies has demonstrated the involvement of MCH in the control of energy balance and the reproductive axis. Information about the hormonal regulation of MCH neurons in non-mammalian systems is scarce and nothing is known about its role in the regulation of the reproductive axis. We here report the molecular characterization of two MCH precursors in the goldfish. Both precursors are peripherally expressed and the expression in the central nervous system is restricted to the mediobasal hypothalamus. Hypothalamic MCH-mRNA production is upregulated during white background adaptation. Both testosterone and estradiol stimulate MCH mRNA expression in the hypothalamus in a sex-dependent manner, with females showing the greatest responsiveness. In addition, in vitro experiments demonstrated that graded doses of salmon MCH stimulate LH, but not GH, secretion from dispersed pituitary cells. Results suggest that hypothalamic MCH may participate in the steroid positive feedback loop on pituitary LH secretion.
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Volkoff H, Canosa LF, Unniappan S, Cerdá-Reverter JM, Bernier NJ, Kelly SP, Peter RE. Neuropeptides and the control of food intake in fish. Gen Comp Endocrinol 2005; 142:3-19. [PMID: 15862543 DOI: 10.1016/j.ygcen.2004.11.001] [Citation(s) in RCA: 388] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Revised: 11/06/2004] [Accepted: 11/09/2004] [Indexed: 11/21/2022]
Abstract
The brain, particularly the hypothalamus, integrates input from factors that stimulate (orexigenic) and inhibit (anorexigenic) food intake. In fish, the identification of appetite regulators has been achieved by the use of both peptide injections followed by measurements of food intake, and by molecular cloning combined with gene expression studies. Neuropeptide Y (NPY) is the most potent orexigenic factor in fish. Other orexigenic peptides, orexin A and B and galanin, have been found to interact with NPY in the control of food intake in an interdependent and coordinated manner. On the other hand cholecystokinin (CCK), cocaine and amphetamine-regulated transcript (CART), and corticotropin-releasing factor (CRF) are potent anorexigenic factors in fish, the latter being involved in stress-related anorexia. CCK and CART have synergistic effects on food intake and modulate the actions of NPY and orexins. Although leptin has not yet been identified in fish, administration of mammalian leptin inhibits food intake in goldfish. Moreover, leptin induces CCK gene expression in the hypothalamus and its actions are mediated at least in part by CCK. Other orexigenic factors have been identified in teleost fish, including the agouti-related protein (AgRP) and ghrelin. Additional anorexigenic factors include bombesin (or gastrin-releasing peptide), alpha-melanocyte-stimulating hormone (alpha-MSH), tachykinins, and urotensin I. In goldfish, nutritional status can modify the expression of mRNAs encoding a number of these peptides, which provides further evidence for their roles as appetite regulators: (1) brain mRNA expression of CCK, CART, tachykinins, galanin, ghrelin, and NPY undergo peri-prandial variations; and (2) fasting increases the brain mRNA expression of NPY, AgRP, and ghrelin as well as serum ghrelin levels, and decreases the brain mRNA expression of tachykinins, CART, and CCK. This review will provide an overview of recent findings in this field.
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Affiliation(s)
- H Volkoff
- Department of Biology, Memorial University of Newfoundland, St John's, NL, Canada A1B 3X9
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Inoue K, Takei Y. Asian medaka fishes offer new models for studying mechanisms of seawater adaptation. Comp Biochem Physiol B Biochem Mol Biol 2003; 136:635-45. [PMID: 14662290 DOI: 10.1016/s1096-4959(03)00204-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Japanese medaka (Oryzias latipes) is a freshwater (FW) teleost that is popular throughout the world for laboratory use. In this paper, we discuss the utility of Japanese medaka and related species for studying mechanisms of seawater (SW) adaptation. In addition to general advantages as an experimental animal such as their daily spawning activity, transparency of embryos, short generation time and established transgenic techniques, Japanese medaka have some adaptability to SW unlike the strictly stenohaline zebrafish (Danio rerio). Since other species in the genus Oryzias exhibit different degrees of adaptability to SW, comparative studies between Japanese medaka, where molecular-biological and genetic information is abundant, and other Oryzias species are expected to present varying approaches to solving the problems of SW adaptation. We introduce some examples of interspecies comparison for SW adaptabilities both in adult fish and in embryos. Oryzias species are good models for evolutionary, ecological and zoogeographical studies and a relationship between SW adaptability and geographic distribution has been suggested. Medaka fishes may thus deliver new insights into our understanding of how fish have expanded their distribution to a wide variety of osmotic environments.
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Affiliation(s)
- Koji Inoue
- Ocean Research Institute, The University of Tokyo, 1-15-1 Minamidai, Nakano, Tokyo 164-8639, Japan.
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21
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Chapter II The melanin-concentrating hormone. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0924-8196(02)80004-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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