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Huang L, Deng X, Yang X, Tang Z, Fan S, Zhou Z, Tao M, Liu S. Cloning, distribution, and effects of growth regulation of MC3R and MC4R in red crucian carp ( Carassius auratus red var.). Front Endocrinol (Lausanne) 2024; 14:1310000. [PMID: 38322156 PMCID: PMC10846643 DOI: 10.3389/fendo.2023.1310000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/27/2023] [Indexed: 02/08/2024] Open
Abstract
Background Melanocortin-3 and -4 receptors (MC3R and MC4R), G protein-coupled receptors, play vital roles in the regulation of energy homeostasis. To understand the functions of mc3r and mc4r in the energy homeostasis of red crucian carp (Carassius auratus red var., RCC), we cloned mc3r and mc4r, analyzed the tissue expression and localization of the genes, and investigated the effects of knockout of mc3r (mc3r +/-) and mc4r (mc4r +/-) in RCC. Results The full-length cDNAs of RCC mc3r and mc4r were 1459 base pairs (bp) and 1894 bp, respectively. qRT-PCR indicated that mc3r and mc4r were profusely expressed in the brain, but lower expressed in the periphery tissues. ISH revealed that mc3r and mc4r were located in NPP, NPO, NAPv, NSC, NAT, NRL, NLTl, and NLTp of the brain, suggesting that mc3r and mc4r might regulate many physiological and behavioral aspects in RCC. To further verify the roles of mc3r and mc4r in energy homeostasis, the mc3r+/- and mc4r+/- fish were obtained by the CRISPR/Cas9 system. The average body weights, total lengths, body depths, and food intake of mc4r+/- fish were significantly higher than those of mc3r+/- and the normal wild-type (WT) fish, but there was no difference between the mc3r+/- and WT fish, indicating that the RCC phenotype and food intake were mainly influenced by mc4r but not mc3r. Interestingly, mc4r+/- fish displayed more visceral fat mass than mc3r+/- and WT fish, and mc3r+/- fish also exhibited slightly more visceral fat mass compared to WT. RNA-seq of the liver and muscle revealed that a large number of differentially expressed genes (DEGs) differed in WT vs. mc3r+/-, WT vs. mc4r+/-, and mc3r+/- vs. mc4r+/-, mainly related to lipid, glucose, and energy metabolism. The KEGG enrichment analysis revealed that DEGs were mainly enriched in pathways such as steroid biosynthesis, fatty acid metabolism, fatty acid biosynthesis, glycolysis/gluconeogenesis, wnt signaling pathway, PPAR signaling pathway, and MAPK signaling pathway, thereby affecting lipid accumulation and growth. Conclusion In conclusion, these results will assist in the further investigation of the molecular mechanisms in which MC3R and MC4R were involved in the regulation of energy homeostasis in fish.
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Affiliation(s)
| | | | | | | | | | | | - Min Tao
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Shaojun Liu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
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Lal NK, Le P, Aggarwal S, Zhang A, Wang K, Qi T, Pang Z, Yang D, Nudell V, Yeo GW, Banks AS, Ye L. Xiphoid nucleus of the midline thalamus controls cold-induced food seeking. Nature 2023; 621:138-145. [PMID: 37587337 PMCID: PMC10482681 DOI: 10.1038/s41586-023-06430-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 07/12/2023] [Indexed: 08/18/2023]
Abstract
Maintaining body temperature is calorically expensive for endothermic animals1. Mammals eat more in the cold to compensate for energy expenditure2, but the neural mechanism underlying this coupling is not well understood. Through behavioural and metabolic analyses, we found that mice dynamically switch between energy-conservation and food-seeking states in the cold, the latter of which are primarily driven by energy expenditure rather than the sensation of cold. To identify the neural mechanisms underlying cold-induced food seeking, we used whole-brain c-Fos mapping and found that the xiphoid (Xi), a small nucleus in the midline thalamus, was selectively activated by prolonged cold associated with elevated energy expenditure but not with acute cold exposure. In vivo calcium imaging showed that Xi activity correlates with food-seeking episodes under cold conditions. Using activity-dependent viral strategies, we found that optogenetic and chemogenetic stimulation of cold-activated Xi neurons selectively recapitulated food seeking under cold conditions whereas their inhibition suppressed it. Mechanistically, Xi encodes a context-dependent valence switch that promotes food-seeking behaviours under cold but not warm conditions. Furthermore, these behaviours are mediated by a Xi-to-nucleus accumbens projection. Our results establish Xi as a key region in the control of cold-induced feeding, which is an important mechanism in the maintenance of energy homeostasis in endothermic animals.
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Affiliation(s)
- Neeraj K Lal
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Phuong Le
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Samarth Aggarwal
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Alan Zhang
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Kristina Wang
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Tianbo Qi
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Zhengyuan Pang
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Dong Yang
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Victoria Nudell
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Alexander S Banks
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Li Ye
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, USA.
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.
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Ji RL, Liu T, Hou ZS, Wen HS, Tao YX. Divergent Pharmacology and Biased Signaling of the Four Melanocortin-4 Receptor Isoforms in Rainbow Trout ( Oncorhynchus mykiss). Biomolecules 2023; 13:1248. [PMID: 37627313 PMCID: PMC10452266 DOI: 10.3390/biom13081248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/13/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
The melanocortin-4 receptor (MC4R) is essential for the modulation of energy balance and reproduction in both fish and mammals. Rainbow trout (Oncorhynchus mykiss) has been extensively studied in various fields and provides a unique opportunity to investigate divergent physiological roles of paralogues. Herein we identified four trout mc4r (mc4ra1, mc4ra2, mc4rb1, and mc4rb2) genes. Four trout Mc4rs (omMc4rs) were homologous to those of teleost and mammalian MC4Rs. Multiple sequence alignments, a phylogenetic tree, chromosomal synteny analyses, and pharmacological studies showed that trout mc4r genes may have undergone different evolutionary processes. All four trout Mc4rs bound to two peptide agonists and elevated intracellular cAMP levels dose-dependently. High basal cAMP levels were observed at two omMc4rs, which were decreased by Agouti-related peptide. Only omMc4rb2 was constitutively active in the ERK1/2 signaling pathway. Ipsen 5i, ML00253764, and MCL0020 were biased allosteric modulators of omMc4rb1 with selective activation upon ERK1/2 signaling. ML00253764 behaved as an allosteric agonist in Gs-cAMP signaling of omMc4rb2. This study will lay the foundation for future physiological studies of various mc4r paralogs and reveal the evolution of MC4R in vertebrates.
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Affiliation(s)
- Ren-Lei Ji
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA; (R.-L.J.); (T.L.)
| | - Ting Liu
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA; (R.-L.J.); (T.L.)
| | - Zhi-Shuai Hou
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA; (R.-L.J.); (T.L.)
| | - Hai-Shen Wen
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266100, China;
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA; (R.-L.J.); (T.L.)
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4
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Lal NK, Le P, Aggarwal S, Zhang A, Wang K, Qi T, Pang Z, Yang D, Nudell V, Yeo GW, Banks AS, Ye L. Xiphoid nucleus of the midline thalamus controls cold-induced food seeking. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.16.533067. [PMID: 36993706 PMCID: PMC10055253 DOI: 10.1101/2023.03.16.533067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Maintaining body temperature is calorically expensive for endothermic animals. Mammals eat more in the cold to compensate for energy expenditure, but the neural mechanism underlying this coupling is not well understood. Through behavioral and metabolic analyses, we found that mice dynamically switch between energy conservation and food-seeking states in the cold, the latter of which is primarily driven by energy expenditure rather than the sensation of cold. To identify the neural mechanisms underlying cold-induced food seeking, we use whole-brain cFos mapping and found that the xiphoid (Xi), a small nucleus in the midline thalamus, was selectively activated by prolonged cold associated with elevated energy expenditure but not with acute cold exposure. In vivo calcium imaging showed that Xi activity correlates with food-seeking episodes in cold conditions. Using activity-dependent viral strategies, we found that optogenetic and chemogenetic stimulation of cold-activated Xi neurons recapitulated cold-induced feeding, whereas their inhibition suppressed it. Mechanistically, Xi encodes a context-dependent valence switch promoting food-seeking behaviors in cold but not warm conditions. Furthermore, these behaviors are mediated by a Xi to nucleus accumbens projection. Our results establish Xi as a key region for controlling cold-induced feeding, an important mechanism for maintaining energy homeostasis in endothermic animals.
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Coogan M, Alston V, Su B, Khalil K, Elaswad A, Khan M, Johnson A, Xing D, Li S, Wang J, Simora RMC, Lu C, Page-McCaw P, Chen W, Michel M, Wang W, Hettiarachchi D, Hasin T, Butts IAE, Cone RD, Dunham RA. Improved Growth and High Inheritance of Melanocortin-4 Receptor (mc4r) Mutation in CRISPR/Cas-9 Gene-Edited Channel Catfish, Ictalurus punctatus. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:843-855. [PMID: 35943638 DOI: 10.1007/s10126-022-10146-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Effects of CRISPR/Cas9 knockout of the melanocortin-4 receptor (mc4r) gene in channel catfish, Ictalurus punctatus, were investigated. Three sgRNAs targeting the channel catfish mc4r gene in conjunction with Cas9 protein were microinjected in embryos and mutation rate, inheritance, and growth were studied. Efficient mutagenesis was achieved as demonstrated by PCR, Surveyor® assay, and DNA sequencing. An overall mutation rate of 33% and 33% homozygosity/bi-allelism was achieved in 2017. Approximately 71% of progeny inherited the mutation. Growth was generally higher in MC4R mutants than controls (CNTRL) at all life stages and in both pond and tank environments. There was a positive relationship between zygosity and growth, with F1 homozygous/bi-allelic mutants reaching market size 30% faster than F1 heterozygotes in earthen ponds (p = 0.022). At the stocker stage (~ 50 g), MC4R × MC4R mutants generated in 2019 were 40% larger than the mean of combined CNTRL × CNTRL families (p = 0.005) and 54% larger than F1 MC4R × CNTRL mutants (p = 0.001) indicating mutation may be recessive. With a high mutation rate and inheritance of the mutation as well as improved growth, the use of gene-edited MC4R channel catfish appears to be beneficial for application on commercial farms.
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Affiliation(s)
- Michael Coogan
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - Veronica Alston
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Baofeng Su
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Karim Khalil
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Ahmed Elaswad
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Department of Animal Wealth Development, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt
| | - Mohd Khan
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Department of Fisheries Biology and Genetics, Agricultural University, Mymensingh, 2202, Bangladesh
| | - Andrew Johnson
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - De Xing
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Shangjia Li
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Jinhai Wang
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Rhoda M C Simora
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 5023, Miagao, Iloilo, Philippines
| | - Cuiyu Lu
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Patrick Page-McCaw
- Department of Molecular and Integrative Physiology, Vanderbilt University, Nashville, TN, 37203-5721, USA
| | - Wenbiao Chen
- Department of Molecular and Integrative Physiology, Vanderbilt University, Nashville, TN, 37203-5721, USA
| | - Max Michel
- Department of Molecular and Integrative Physiology, Vanderbilt University, Nashville, TN, 37203-5721, USA
| | - Wenwen Wang
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | | | - Tasnuba Hasin
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Ian A E Butts
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Roger D Cone
- Department of Molecular and Integrative Physiology, Vanderbilt University, Nashville, TN, 37203-5721, USA
| | - Rex A Dunham
- Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
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Yuan XC, Tao YX. Ligands for Melanocortin Receptors: Beyond Melanocyte-Stimulating Hormones and Adrenocorticotropin. Biomolecules 2022; 12:biom12101407. [PMID: 36291616 PMCID: PMC9599618 DOI: 10.3390/biom12101407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
The discovery of melanocortins in 1916 has resulted in more than 100 years of research focused on these peptides. Extensive studies have elucidated well-established functions of melanocortins mediated by cell surface receptors, including MSHR (melanocyte-stimulating hormone receptor) and ACTHR (adrenocorticotropin receptor). Subsequently, three additional melanocortin receptors (MCRs) were identified. Among these five MCRs, MC3R and MC4R are expressed primarily in the central nervous system, and are therefore referred to as the neural MCRs. Since the central melanocortin system plays important roles in regulating energy homeostasis, targeting neural MCRs is emerging as a therapeutic approach for treating metabolic conditions such as obesity and cachexia. Early efforts modifying endogenous ligands resulted in the development of many potent and selective ligands. This review focuses on the ligands for neural MCRs, including classical ligands (MSH and agouti-related peptide), nonclassical ligands (lipocalin 2, β-defensin, small molecules, and pharmacoperones), and clinically approved ligands (ACTH, setmelanotide, bremelanotide, and several repurposed drugs).
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Affiliation(s)
- Xiao-Chen Yuan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230061, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
- Correspondence:
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Guo B, He X, Ge C, Xue M, Wang J, Longshaw M, Wang J, Liang X. A Natural Gas Fermentation Bacterial Meal (FeedKind®) as a Functional Alternative Ingredient for Fishmeal in Diet of Largemouth Bass, Micropterus salmoides. Antioxidants (Basel) 2022; 11:antiox11081479. [PMID: 36009198 PMCID: PMC9405052 DOI: 10.3390/antiox11081479] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/21/2022] [Accepted: 07/26/2022] [Indexed: 02/05/2023] Open
Abstract
A 10-week growth study was conducted to evaluate the effect of a natural gas fermentation bacterial meal (FeedKind®, FK) as a fishmeal (FM) alternative in largemouth bass (Micropterus salmoides) (48.0 ± 0.03 g). Four isonitrogenous and isoenergetic diets were formulated including one commercial control (C, 42% FM) and three experimental diets with gradient FK of 3% (FK3, 29%FM), 6% (FK6, 26%FM) and 9% (FK9, 23%FM), respectively. FK-fed groups showed significantly higher SR than that of C group. The WGR and SGR of fish fed FK3 and FK6 were significantly higher than those of FK9, but not statistical different from the C group. FK-fed groups showed higher apparent digestibility coefficients of dry matter and nutrients. Further, FK-fed groups increased the ratio of SOD/MDA in the plasma and liver, and the upregulation of intestinal Keap1 and downregulation of HIF1α was found in FK3. Furthermore, FK-fed groups showed higher microbial richness and diversity. Pearson correlation analysis found that antioxidant relevant biomarkers were negatively correlated with the relative abundance of certain potential beneficial bacteria. In conclusion, supplemented up to 3–6% FK replacing FM in a low FM diet of largemouth bass could increase growth, survival rate, antioxidant capacity, and improve gut microbiota.
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Affiliation(s)
- Boyuan Guo
- National Aquafeed Safety Assessment Center, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (B.G.); (X.H.); (C.G.); (M.X.)
| | - Xia He
- National Aquafeed Safety Assessment Center, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (B.G.); (X.H.); (C.G.); (M.X.)
| | - Chunyu Ge
- National Aquafeed Safety Assessment Center, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (B.G.); (X.H.); (C.G.); (M.X.)
| | - Min Xue
- National Aquafeed Safety Assessment Center, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (B.G.); (X.H.); (C.G.); (M.X.)
| | - Jia Wang
- Calysta (China) Company Limited, Shanghai 200041, China;
| | - Matt Longshaw
- Calysta (UK) Company Limited, Redcar TS10 4RF, Cleveland, UK;
| | - Jie Wang
- Feed Processing and Quality Control Innovation Team, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Correspondence: (J.W.); (X.L.)
| | - Xiaofang Liang
- National Aquafeed Safety Assessment Center, Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (B.G.); (X.H.); (C.G.); (M.X.)
- Correspondence: (J.W.); (X.L.)
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Tao YX. Mutations in melanocortin-4 receptor: From fish to men. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 189:215-257. [PMID: 35595350 DOI: 10.1016/bs.pmbts.2022.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Melanocortin-4 receptor (MC4R), expressed abundantly in the hypothalamus, is a critical regulator of energy homeostasis, including both food intake and energy expenditure. Shortly after the publication in 1997 of the Mc4r knockout phenotypes in mice, including increased food intake and severe obesity, the first mutations in MC4R were reported in humans in 1998. Studies in the subsequent two decades have established MC4R mutation as the most common monogenic form of obesity, especially in early-onset severe obesity. Studies in animals, from fish to mammals, have established the conserved physiological roles of MC4R in all vertebrates in regulating energy balance. Drug targeting MC4R has been recently approved for treating morbid genetic obesity. How the MC4R can be exploited for animal production is highly worthy of active investigation.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States.
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Cui X, Gruzdeva A, Kim H, Yapici N. Of flies, mice and neural control of food intake: lessons to learn from both models. Curr Opin Neurobiol 2022; 73:102531. [PMID: 35390643 PMCID: PMC9167741 DOI: 10.1016/j.conb.2022.102531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/20/2022] [Accepted: 03/02/2022] [Indexed: 11/03/2022]
Abstract
In her book, A Room of One's Own, the famous author Virginia Woolf writes "One cannot think well, love well, sleep well if one has not dined well". This is true. All animals need to forage for food and consume specific nutrients to maintain their physiological homeostasis, maximize their fitness and their reproduction. After decades of research in humans and many model organisms, we now know that our brain is one of the key players that control what, when, and how much we eat. In this review, we discuss the recent literature on neural control of food intake behaviors in mice and flies with the view that these two model organisms complement one another in efforts to uncover conserved principles brains use to regulate energy metabolism and food ingestion.
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Affiliation(s)
- Xinyue Cui
- Department of Neurobiology and Behavior, Cornell University, 14853, Ithaca, NY, USA
| | - Anna Gruzdeva
- Department of Neurobiology and Behavior, Cornell University, 14853, Ithaca, NY, USA
| | - Haein Kim
- Department of Neurobiology and Behavior, Cornell University, 14853, Ithaca, NY, USA
| | - Nilay Yapici
- Department of Neurobiology and Behavior, Cornell University, 14853, Ithaca, NY, USA.
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Padeniya U, Larson ET, Septriani S, Pataueg A, Kafui AR, Hasan E, Mmaduakonam OS, Kim GD, Kiddane AT, Brown CL. Probiotic Treatment Enhances Pre-feeding Larval Development and Early Survival in Zebrafish Danio rerio. JOURNAL OF AQUATIC ANIMAL HEALTH 2022; 34:3-11. [PMID: 35315145 DOI: 10.1002/aah.10148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 12/03/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
The growth and development of healthy culture subjects are essential in increasing productivity in the aquaculture industry. A primary determinant of aquatic animal productivity is the ambient microbial population. If an aquatic animal's microbiome is diverse, with bacteria favoring beneficial over pathogenic species, the health and growth of the animal (i.e., fish or crustacean) can be substantially improved. Embryonic and newly hatched Zebrafish Danio rerio larvae were reared in the presence of (1) water from the broodstock culture tank as a control, (2) a probiotic solution containing 19 strains of live lactic acid bacteria (LAB), or (3) an antibiotic (AB) solution with amoxycillin. Developmental parameters were monitored until 10 d postfertilization. Bacteria present in the water and larvae were cultured and identified by sequencing the V4 hypervariable region of bacterial 16S ribosomal RNA. Probiotic-treated larvae showed significant increases in every measured morphological parameter and in survival compared to the controls and AB-treated larvae, including TL, eye development, and swim bladder development before first feeding. Staining with DASPEI (2-(4-[dimethylamino]styryl)-N-ethylpyridinium iodide) produced fluorescence, revealing increased mitochondrial activity in the gastrointestinal tracts of probiotic-treated larvae and reflecting advancement of initial metabolic function. Probiotic-treated larvae showed accelerated yolk absorption, resulting in increased nutrient mobilization and growth. Microbial analyses revealed a greater concentration of bacteria in larvae in response to the probiotic treatment compared to the other two treatments. Species identified in all three treatments included Pseudomonas spp. and Aeromonas spp. (Proteobacteria). The second most diverse and abundant microbiome was seen in controls, whereas AB-treated larvae had the least diverse microbiome. All treatments revealed the presence of proteobacteria, but an AB-resistant pathogenic bacterium (Stenotrophomonas maltophilia) was identified in the AB group. These results reveal that the presence of LAB and other bacteria favorably influenced early larval growth, development, digestive function, and survival in Zebrafish even before the onset of feeding.
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Affiliation(s)
- Uthpala Padeniya
- Food and Agriculture Organization of the United Nations, World Fisheries University Pilot Programme, Pukyong National University, Busan, 48547, South Korea
| | - Earl T Larson
- Department of Biological Sciences, St. Johns River State College, Orange Park, Florida, 32065, USA
| | - Shafira Septriani
- Food and Agriculture Organization of the United Nations, World Fisheries University Pilot Programme, Pukyong National University, Busan, 48547, South Korea
| | - Arjay Pataueg
- Food and Agriculture Organization of the United Nations, World Fisheries University Pilot Programme, Pukyong National University, Busan, 48547, South Korea
| | - Akpoh Rhoda Kafui
- Food and Agriculture Organization of the United Nations, World Fisheries University Pilot Programme, Pukyong National University, Busan, 48547, South Korea
| | - Ekramul Hasan
- Food and Agriculture Organization of the United Nations, World Fisheries University Pilot Programme, Pukyong National University, Busan, 48547, South Korea
| | - Obodoefuna Somadina Mmaduakonam
- Food and Agriculture Organization of the United Nations, World Fisheries University Pilot Programme, Pukyong National University, Busan, 48547, South Korea
| | - Gun-Do Kim
- Lab of Cell Signaling, Department of Microbiology, College of Natural Science, Pukyong National University, Busan, 48547, South Korea
| | - Anley Teferra Kiddane
- Lab of Cell Signaling, Department of Microbiology, College of Natural Science, Pukyong National University, Busan, 48547, South Korea
| | - Christopher L Brown
- Food and Agriculture Organization of the United Nations, World Fisheries University Pilot Programme, Pukyong National University, Busan, 48547, South Korea
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Hou ZS, Wen HS. Neuropeptide Y and melanocortin receptors in fish: regulators of energy homeostasis. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:42-51. [PMID: 37073356 PMCID: PMC10077275 DOI: 10.1007/s42995-021-00106-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 04/19/2021] [Indexed: 05/03/2023]
Abstract
Energy homeostasis, which refers to the physiological processes that the energy intake is exquisitely coordinated with energy expenditure, is critical for survival. Therefore, multiple and complex mechanisms have been involved in the regulation of energy homeostasis. The central melanocortin system plays an important role in modulating energy homeostasis. This system includes the orexigenic neurons, expressing neuropeptide Y/Agouti-related protein (NPY/AgRP), and the anorexigenic neurons expressing proopiomelanocortin (POMC). The downstream receptors of NPY, AgRP and post-translational products of POMC are G protein-coupled receptors (GPCRs). This review summarizes the compelling evidence demonstrating that NPY and melanocortin receptors are involved in energy homeostasis. Subsequently, the comparative studies on physiology and pharmacology of NPY and melanocortin receptors in humans, rodents and teleosts are summarized. Also, we provide a strategy demonstrating the potential application of the new ligands and/or specific variants of melanocortin system in aquaculture.
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Affiliation(s)
- Zhi-Shuai Hou
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education (KLMME), Fisheries College, Ocean University of China, Qingdao, 266003 China
| | - Hai-Shen Wen
- Key Laboratory of Mariculture (Ocean University of China), Ministry of Education (KLMME), Fisheries College, Ocean University of China, Qingdao, 266003 China
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12
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Vargas-Chacoff L, Regish AM, Weinstock A, Björnsson BT, McCormick SD. Effects of long-term cortisol treatment on growth and osmoregulation of Atlantic salmon and brook trout. Gen Comp Endocrinol 2021; 308:113769. [PMID: 33794274 DOI: 10.1016/j.ygcen.2021.113769] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/14/2021] [Accepted: 03/25/2021] [Indexed: 12/23/2022]
Abstract
Cortisol is the final product of the hypothalamic-pituitary-interrenal (HPI) axis and acts as a gluco- and mineralo-corticoid in fish. Long-term elevations of cortisol have been linked to reduced growth in fishes, but the mechanism(s) and relative sensitivities of species are still unclear. We carried out experiments to examine the relative effects of cortisol on growth and gill NKA activity in two salmonids: Atlantic salmon (Salmo salar) and brook trout (Salvelinus fontinalis). Treatment with intraperitoneal cortisol implants for 30 days resulted in reduced growth in both species, but with greater sensitivity to cortisol in brook trout. Gill NKA activity was strongly upregulated by cortisol in Atlantic salmon, and weakly upregulated in brook trout but with no statistically significant effect. Cortisol treatment resulted in reduced plasma levels of insulin-like growth factor I and increased plasma growth hormone levels in Atlantic salmon. Our results demonstrate that there are species differences in the sensitivity of growth and osmoregulation to cortisol, even among species in the same family (Salmonidae).
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Affiliation(s)
- L Vargas-Chacoff
- Instituto de Ciencias Marinas y Limnológicas, Laboratorio de Fisiología de Peces, Universidad Austral de Chile, Valdivia, Chile; U.S. Geological Survey, Eastern Ecological Science Center, Conte Research Laboratory, Turners Falls, MA, USA; Fondap-IDEAL, Universidad Austral de Chile, Valdivia, Chile.
| | - A M Regish
- U.S. Geological Survey, Eastern Ecological Science Center, Conte Research Laboratory, Turners Falls, MA, USA
| | - A Weinstock
- U.S. Geological Survey, Eastern Ecological Science Center, Conte Research Laboratory, Turners Falls, MA, USA
| | - B Th Björnsson
- Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - S D McCormick
- U.S. Geological Survey, Eastern Ecological Science Center, Conte Research Laboratory, Turners Falls, MA, USA; Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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13
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Gallman K, Fortune E, Rivera D, Soares D. Differences in behavior between surface and cave Astyanax mexicanus may be mediated by changes in catecholamine signaling. J Comp Neurol 2020; 528:2639-2653. [PMID: 32291742 DOI: 10.1002/cne.24923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 04/02/2020] [Accepted: 04/04/2020] [Indexed: 11/07/2022]
Abstract
Astyanax mexicanus is a teleost fish that is in the process of allopatric speciation. Ancestral Astyanax are found in surface rivers and derived blind forms are found in cave systems. Adaptation to life in nutrient poor caves without predation includes the evolution of enhanced food seeking behaviors and loss of defensive responses. These behavioral adaptations may be mediated by changes in catecholaminergic control systems in the brain. We examined the distribution of tyrosine hydroxylase, a conserved precursor for the synthesis of the catecholamines dopamine and noradrenaline, in the brains of surface and cave Astyanax using immunohistochemistry. We found differences in tyrosine hydroxylase staining in regions that are associated with nonvisual sensory perception, motor control, endocrine release, and attention. These differences included significant increases in the diameters of tyrosine hydroxylase immunoreactive soma in cave Astyanax in the olfactory bulb, basal telencephalon, preoptic nuclei, ventral thalamus, posterior tuberculum, and locus coeruleus. These increases in modulation by dopamine and noradrenaline likely indicate changes in behavioral control that underlie adaptations to the cave environment.
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Affiliation(s)
- Kathryn Gallman
- Biological Sciences, New Jersey Institute of Technology, New Jersey, USA
| | - Eric Fortune
- Biological Sciences, New Jersey Institute of Technology, New Jersey, USA
| | - Daihana Rivera
- Biological Sciences, New Jersey Institute of Technology, New Jersey, USA
| | - Daphne Soares
- Biological Sciences, New Jersey Institute of Technology, New Jersey, USA
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14
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Kasagi S, Miura M, Okazaki T, Mizusawa K, Takahashi A. Effects of tank color brightness on the body color, somatic growth, and endocrine systems of rainbow trout Oncorhynchus mykiss. Gen Comp Endocrinol 2020; 298:113581. [PMID: 32800773 DOI: 10.1016/j.ygcen.2020.113581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/03/2020] [Accepted: 08/07/2020] [Indexed: 12/14/2022]
Abstract
We investigated the effects of tank brightness on body color, growth, and endocrine systems of rainbow trout (Oncorhynchus mykiss). Five different tank colors that produce varying levels of brightness were used, including black, dark gray [DG], light gray [LG], white, and blue. The fish were reared in these tanks for 59 days under natural photoperiod and water temperature. The body color was affected by tank brightness, such that body color brightness was correlated with tank brightness (white-housed ≥ LG-housed ≥ DG-housed ≥ blue-housed ≥ black-housed). No difference in somatic growth was observed among the fish reared in the five tanks. The mRNA levels of melanin-concentrating hormone (mch1) was higher in white-housed fish than those in the other tanks, and the mRNA levels of proopiomelanocortins (pomc-a and pomc-b) were higher in fish housed in a black tank than those in other tanks. mRNA level of somatolactin, a member of growth hormone family, was higher in black-housed fish than those in white-housed fish. The mRNA levels of mch1 and mch2 in blue-housed fish were similar to those in black-housed fish, while the mRNA levels of pomc-a and pomc-b in blue-housed fish were similar to those in white-housed fish. The current results suggest that tank color is not related to fish growth, therefore any color of conventional rearing tank can be used to grow fish. Moreover, the association between somatolactin with body color changes is suggested in addition to the role of classical MCH and melanophore stimulating hormone derived from POMC.
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Affiliation(s)
- Satoshi Kasagi
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan.
| | - Masayuki Miura
- Oshino Branch, Yamanashi Prefectural Fisheries Technology Center, Oshino, Yamanashi 401-0511, Japan
| | - Takumi Okazaki
- Oshino Branch, Yamanashi Prefectural Fisheries Technology Center, Oshino, Yamanashi 401-0511, Japan
| | - Kanta Mizusawa
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
| | - Akiyoshi Takahashi
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
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15
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Melanocortin Receptor 4 (MC4R) Signaling System in Nile Tilapia. Int J Mol Sci 2020; 21:ijms21197036. [PMID: 32987823 PMCID: PMC7582737 DOI: 10.3390/ijms21197036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 09/18/2020] [Accepted: 09/18/2020] [Indexed: 12/13/2022] Open
Abstract
The melanocortin receptor 4 (MC4R) signaling system consists of MC4R, MC4R ligands [melanocyte-stimulating hormone (MSH), adrenocorticotropin (ACTH), agouti-related protein (AgRP)], and melanocortin-2 receptor accessory protein 2 (MRAP2), and it has been proposed to play important roles in feeding and growth in vertebrates. However, the expression and functionality of this system have not been fully characterized in teleosts. Here, we cloned tilapia MC4R, MRAP2b, AgRPs (AgRP, AgRP2), and POMCs (POMCa1, POMCb) genes and characterized the interaction of tilapia MC4R with MRAP2b, AgRP, α-MSH, and ACTH in vitro. The results indicate the following. (1) Tilapia MC4R, MRAP2b, AgRPs, and POMCs share high amino acid identity with their mammalian counterparts. (2) Tilapia MRAP2b could interact with MC4R expressed in CHO cells, as demonstrated by Co-IP assay, and thus decrease MC4R constitutive activity and enhance its sensitivity to ACTH1-40. (3) As in mammals, AgRP can function as an inverse agonist and antagonist of MC4R, either in the presence or absence of MRAP2b. These data, together with the co-expression of MC4R, MRAP2b, AgRPs, and POMCs in tilapia hypothalamus, suggest that as in mammals, ACTH/α-MSH, AgRP, and MRAP2 can interact with MC4R to control energy balance and thus play conserved roles in the feeding and growth of teleosts.
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Kalananthan T, Lai F, Gomes AS, Murashita K, Handeland S, Rønnestad I. The Melanocortin System in Atlantic Salmon ( Salmo salar L.) and Its Role in Appetite Control. Front Neuroanat 2020; 14:48. [PMID: 32973463 PMCID: PMC7471746 DOI: 10.3389/fnana.2020.00048] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 07/09/2020] [Indexed: 12/15/2022] Open
Abstract
The melanocortin system is a key neuroendocrine network involved in the control of food intake and energy homeostasis in vertebrates. Within the hypothalamus, the system comprises two main distinct neuronal cell populations that express the neuropeptides proopiomelanocortin (POMC; anorexigenic) or agouti-related protein (AGRP; orexigenic). Both bind to the melanocortin-4 receptor (MC4R) in higher order neurons that control both food intake and energy expenditure. This system is relatively well-conserved among vertebrates. However, in Atlantic salmon (Salmo salar L.), the salmonid-specific fourth round whole-genome duplication led to the presence of several paralog genes which might result in divergent functions of the duplicated genes. In the current study, we report the first comprehensive comparative identification and characterization of Mc4r and extend the knowledge of Pomc and Agrp in appetite control in Atlantic salmon. In silico analysis revealed multiple paralogs for mc4r (a1, a2, b1, and b2) in the Atlantic salmon genome and confirmed the paralogs previously described for pomc (a1, a2, and b) and agrp (1 and 2). All Mc4r paralogs are relatively well-conserved with the human homolog, sharing at least 63% amino acid sequence identity. We analyzed the mRNA expression of mc4r, pomc, and agrp genes in eight brain regions of Atlantic salmon post-smolt under two feeding states: normally fed and fasted for 4 days. The mc4ra2 and b1 mRNAs were predominantly and equally abundant in the hypothalamus and telencephalon, the mc4rb2 in the hypothalamus, and a1 in the telencephalon. All pomc genes were highly expressed in the pituitary, followed by the hypothalamus and saccus vasculosus. The agrp genes showed a completely different expression pattern from each other, with prevalent expression of the agrp1 in the hypothalamus and agrp2 in the telencephalon. Fasting did not induce any significant changes in the mRNA level of mc4r, agrp, or pomc paralogs in the hypothalamus or in other highly expressed regions between fed and fasted states. The identification and wide distribution of multiple paralogs of mc4r, pomc, and agrp in Atlantic salmon brain provide new insights and give rise to new questions of the melanocortin system in the appetite regulation in Atlantic salmon.
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Affiliation(s)
| | - Floriana Lai
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Ana S Gomes
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Koji Murashita
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,Research Center for Aquaculture Systems, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Tamaki, Japan
| | - Sigurd Handeland
- Department of Biological Sciences, University of Bergen, Bergen, Norway.,Norwegian Research Center, NORCE Environment, Bergen, Norway
| | - Ivar Rønnestad
- Department of Biological Sciences, University of Bergen, Bergen, Norway
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17
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Melanocortin-4 receptor regulation of reproductive function in black rockfish (Sebastes schlegelii). Gene 2020; 741:144541. [PMID: 32165303 DOI: 10.1016/j.gene.2020.144541] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 02/20/2020] [Accepted: 03/08/2020] [Indexed: 01/15/2023]
Abstract
Melanocortin-4 receptor (MC4R) is a G protein-coupled receptor with multiple functions in mammals. However, the functions of MC4R in fish have not been investigated extensively. The purpose of this study was to determine potential regulation of reproduction by the MC4R. We cloned the black rockfish MC4R and analyzed its tissue distribution and function. The results showed that black rockfish mc4r cDNA consisted of 981 nucleotides encoding a protein of 326 amino acids. The quantitative PCR data showed that mc4r mRNA was primarily expressed in the brain, gonad, stomach and intestine. In the brain, mc4r was found to be primarily located in the hypothalamus. Both α-MSH and β-MSH increased gnih expression and decreased sgnrh and cgnrh expression (P < 0.05). α-MSH and β-MSH had opposite effects on kisspeptin expression. In contrast, α-MSH and β-MSH increased the expression of cyp11, cyp19, 3β-hsd and star. In summary, our study shows that MC4R in black rockfish might regulate reproductive function and that the effects of α-MSH and β-MSH might differ.
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18
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Liu R, Kinoshita M, Adolfi MC, Schartl M. Analysis of the Role of the Mc4r System in Development, Growth, and Puberty of Medaka. Front Endocrinol (Lausanne) 2019; 10:213. [PMID: 31024451 PMCID: PMC6463759 DOI: 10.3389/fendo.2019.00213] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/18/2019] [Indexed: 01/23/2023] Open
Abstract
In mammals the melanocortin 4 receptor (Mc4r) signaling system has been mainly associated with the regulation of appetite and energy homeostasis. In fish of the genus Xiphophorus (platyfish and swordtails) puberty onset is genetically determined by a single locus, which encodes the mc4r. Wild populations of Xiphophorus are polymorphic for early and late-maturing individuals. Copy number variation of different mc4r alleles is responsible for the difference in puberty onset. To answer whether this is a special adaptation of the Mc4r signaling system in the lineage of Xiphophorus or a more widely conserved mechanism in teleosts, we studied the role of Mc4r in reproductive biology of medaka (Oryzias latipes), a close relative to Xiphophorus and a well-established model to study gonadal development. To understand the potential role of Mc4r in medaka, we characterized the major features of the Mc4r signaling system (mc4r, mrap2, pomc, agrp1). In medaka, all these genes are expressed before hatching. In adults, they are mainly expressed in the brain. The transcript of the receptor accessory protein mrap2 co-localizes with mc4r in the hypothalamus in adult brains indicating a conserved function of modulating Mc4r signaling. Comparing growth and puberty between wild-type and mc4r knockout medaka revealed that absence of Mc4r does not change puberty timing but significantly delays hatching. Embryonic development of knockout animals is retarded compared to wild-types. In conclusion, the Mc4r system in medaka is involved in regulation of growth rather than puberty.
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Affiliation(s)
- Ruiqi Liu
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Masato Kinoshita
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Mateus C Adolfi
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Manfred Schartl
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
- Comprehensive Cancer Center Mainfranken, University Clinic Wuerzburg, Wuerzburg, Germany
- Hagler Institute for Advanced Study and Department of Biology, Texas A&M University, College Station, TX, United States
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19
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Zhang KQ, Hou ZS, Wen HS, Li Y, Qi X, Li WJ, Tao YX. Melanocortin-4 Receptor in Spotted Sea Bass, Lateolabrax maculatus: Cloning, Tissue Distribution, Physiology, and Pharmacology. Front Endocrinol (Lausanne) 2019; 10:705. [PMID: 31681175 PMCID: PMC6813543 DOI: 10.3389/fendo.2019.00705] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/30/2019] [Indexed: 01/27/2023] Open
Abstract
Melanocortin-4 receptor (MC4R) plays important roles in regulation of multiple physiological processes including energy homeostasis, reproduction, sexual function, and other functions in mammals. Recent studies suggested that teleost MC4Rs have different physiological functions and pharmacological characteristics when compared to mammalian MC4Rs. In this study, we investigated spotted sea bass (Lateolabrax maculatus) MC4R (LmMC4R) physiology and pharmacology. Spotted sea bass mc4r consisted of a 984 bp open reading frame encoding a protein of 327 amino acids. LmMC4R was homologous to those of several teleost MC4Rs and human MC4R (hMC4R). qRT-PCR and in situ hybridization revealed that mc4r transcripts were highly expressed in the brain, followed by pituitary and liver. Brain mc4r transcripts were down-regulated in long-term and short-term fasting challenges. LmMC4R was a functional receptor with lower maximal binding and higher basal activity than hMC4R. THIQ was not able to displace 125I-NDP-MSH but could affect intracellular cAMP accumulation, suggesting that it was an allosteric ligand for LmMC4R. In vitro studies with spotted sea bass brain cells indicated that mRNA levels of neuropeptide Y and Agouti-related peptide were down-regulated by α-MSH. In summary, we cloned spotted sea bass MC4R, and showed that it had different pharmacological properties compared to hMC4R, and potentially different functions.
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Affiliation(s)
- Kai-Qiang Zhang
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Zhi-Shuai Hou
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
| | - Hai-Shen Wen
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Yun Li
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
- *Correspondence: Yun Li
| | - Xin Qi
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Wen-Juan Li
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
- Ya-Xiong Tao
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20
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Parolini M, Iacobuzio R, Bassano B, Pennati R, Saino N. Melanin-Based Skin Coloration Predicts Antioxidant Capacity in the Brown Trout (Salmo trutta). Physiol Biochem Zool 2018; 91:1026-1035. [PMID: 30084732 DOI: 10.1086/699522] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In many vertebrate species, individuals exhibit large variation in the degree of melanin-based coloration on their body. Dark and pale individuals differ in diverse physiological and behavioral traits, suggesting that melanic coloration may reveal individual quality. However, research into the relationships between physiological and skin traits, in terms of melanin-based skin coloration, in wild fish is scant. Our correlative study aimed at investigating the relationships between physiology and melanin-based coloration of the skin of free-living brown trout (Salmo trutta Linnaeus, 1758). We scrutinized the relationships between body condition (body mass and Fulton's K condition factor), oxidative status (plasma total antioxidant capacity and amount of pro-oxidant molecules), and the degree of melanin-based skin coloration assessed by digital photography and image analysis. We found heavier fish to be, on average, darker colored than paler conspecifics. Moreover, a significant covariation between plasma total antioxidant capacity and melanic coloration was noted. Our findings suggest that the melanin-based coloration of brown trout serves as a signal to communicate a better antioxidant defense to conspecifics.
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21
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Morris MR, Friebertshauser RJ, Zupi M, Liotta MN, Dunn G, Kleinas N, Rios-Cardenas O. Feeding Rates in the Swordtail Fish Xiphophorus multilineatus: A Model System for Genetic Variation in Nutritional Programming. Zebrafish 2018; 15:484-491. [DOI: 10.1089/zeb.2018.1624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Molly R. Morris
- Department of Biological Sciences, Ohio University, Athens, Ohio
| | | | - Megan Zupi
- Department of Biological Sciences, Ohio University, Athens, Ohio
| | | | - Garrett Dunn
- Department of Biology, Washington and Jefferson College, Washington, Pennsylvania
| | - Nicole Kleinas
- Department of Biological Sciences, Ohio University, Athens, Ohio
| | - Oscar Rios-Cardenas
- Instituto de Ecología A.C., Red de Biología Evolutiva, Xalapa, Veracruz, México
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22
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Yi TL, Yang LK, Ruan GL, Yang DQ, Tao YX. Melanocortin-4 receptor in swamp eel (Monopterus albus): Cloning, tissue distribution, and pharmacology. Gene 2018; 678:79-89. [PMID: 30075196 DOI: 10.1016/j.gene.2018.07.056] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/14/2018] [Accepted: 07/23/2018] [Indexed: 01/10/2023]
Abstract
Melanocortin-4 receptor (MC4R) plays critical roles in the regulation of various physiological processes, such as energy homeostasis, reproduction and sexual function, cardiovascular function, and other functions in mammals. Although the functions of the MC4R in fish have not been extensively studied, the importance of MC4R in regulation of piscine energy expenditure and sexual functions is emerging. Swamp eel (Monopterus albus) is an economically and evolutionarily important fish widely distributed in tropics and subtropics. We cloned swamp eel mc4r (mamc4r), consisting of a 981 bp open reading frame encoding a protein of 326 amino acids. The sequence of maMC4R was homologous to those of several teleost MC4Rs. Phylogenetic and chromosomal synteny analyses showed that maMC4R was closely related to piscine MC4Rs. qRT-PCR revealed that mc4r transcripts were highly expressed in brain and gonads of swamp eel. The maMC4R was further demonstrated to be a functional receptor by pharmacological studies. Four agonists, α-melanocyte stimulating hormone (α-MSH), β-MSH, [Nle4, D-Phe7]-α-MSH (NDP-MSH), and adrenocorticotropin, could bind to maMC4R and induce intracellular cAMP production dose-dependently. Small molecule agonist THIQ allosterically bound to maMC4R and exerted its effect. Similar to other fish MC4Rs, maMC4R also exhibited significantly increased basal activity compared with that of human MC4R. The high basal activity of maMC4R could be decreased by inverse agonist ML00253764, suggesting that maMC4R was indeed constitutively active. The availability of maMC4R and its pharmacological characteristics will facilitate the investigation of its function in regulating diverse physiological processes in swamp eel.
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Affiliation(s)
- Ti-Lin Yi
- School of Animal Science, Yangtze University, Jingzhou 434020, Hubei, China
| | - Li-Kun Yang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States
| | - Guo-Liang Ruan
- School of Animal Science, Yangtze University, Jingzhou 434020, Hubei, China
| | - Dai-Qin Yang
- School of Animal Science, Yangtze University, Jingzhou 434020, Hubei, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States.
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Kim JH, Chatchaiphan S, Crown MT, White SL, Devlin RH. Effect of growth hormone overexpression on gastric evacuation rate in coho salmon. FISH PHYSIOLOGY AND BIOCHEMISTRY 2018; 44:119-135. [PMID: 28894993 DOI: 10.1007/s10695-017-0418-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 08/22/2017] [Indexed: 06/07/2023]
Abstract
Growth hormone (GH) transgenic (T) coho salmon consistently show remarkably enhanced growth associated with increased appetite and food consumption compared to non-transgenic wild-type (NT) coho salmon. To improve understanding of the mechanism by which GH overexpression mediates food intake and digestion in T fish, feed intake and gastric evacuation rate (over 7 days) were measured in size-matched T and NT coho salmon. T fish displayed greatly enhanced feed intake levels (~ 2.5-fold), and more than 3-fold increase in gastric evacuation rates relative to NT coho salmon. Despite the differences in feed intake, no differences were noted in the time taken from first ingestion of food to stomach evacuation between genotypes. These results indicate that enhanced feed intake is coupled with an overall increased processing rate to enhance energy intake by T fish. To further investigate the molecular basis of these responses, we examined the messenger RNA (mRNA) levels of several genes in appetite- and gastric-regulation pathways (Agrp1, Bbs, Cart, Cck, Glp, Ghrelin, Grp, Leptin, Mc4r, Npy, and Pomc) by qPCR analyses in the brain (hypothalamus, preoptic area) and pituitary, and in peripheral tissues associated with digestion (liver, stomach, intestine, and adipose tissue). Significant increases in mRNA levels were found for Agrp1 in the preoptic area (POA) of the brain, and Grp and Pomc in pituitary for T coho salmon relative to NT. Mch and Npy showed significantly lower mRNA levels than NT fish in all brain tissues examined across all time-points after feeding. Mc4r and Cart for T showed significantly lower mRNA levels than NT in the POA and hypothalamus, respectively. In the case of peripheral tissues, T fish had lower mRNA levels of Glp and Leptin than NT fish in the intestine and adipose tissue, respectively. Grp, Cck, Bbs, Glp, and Leptin in stomach, adipose tissue, and/or intestine showed significant differences across the time-points after feeding, but Ghrelin showed no significant difference between T and NT fish in all tested tissues.
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Affiliation(s)
- Jin-Hyoung Kim
- Fisheries and Oceans Canada, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, BC, Canada
- Unit of Polar Genomics, Korea Polar Research Institute, 26, Songdomirae-ro, Yeonsu-gu, Incheon, Republic of Korea
| | - Satid Chatchaiphan
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, 50 Phaholyothin Road, Bangkok, Thailand
| | - Michelle T Crown
- Fisheries and Oceans Canada, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, BC, Canada
| | - Samantha L White
- Fisheries and Oceans Canada, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, BC, Canada
| | - Robert H Devlin
- Fisheries and Oceans Canada, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, BC, Canada.
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Zhang J, Li X, Zhou Y, Cui L, Li J, Wu C, Wan Y, Li J, Wang Y. The interaction of MC3R and MC4R with MRAP2, ACTH, α-MSH and AgRP in chickens. J Endocrinol 2017; 234:155-174. [PMID: 28512117 DOI: 10.1530/joe-17-0131] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 05/15/2017] [Indexed: 02/05/2023]
Abstract
The interaction of melanocortin-4 (MC4R) and melanocortin-3 (MC3R) receptors with proopiomelanocortin (POMC)-derived peptides (e.g. α-MSH), agouti-related protein (AgRP) and melanocortin-2 receptor accessory protein 2 (MRAP2) is suggested to play critical roles in energy balance of vertebrates. However, evidence on their interaction in birds remains scarce. Our study aims to reveal their interaction in chickens and the results showed that (1) chicken (c-)MC3R and cMC4R expressed in Chinese hamster ovary (CHO) cells can be activated by α-MSH and ACTH1-39 equipotently, monitored by a pGL3-CRE-luciferase reporter system; (2) cMC3R and cMC4R, when co-expressed with cMRAP2 (or cMRAP, a cMRAP2 homolog), show increased sensitivity to ACTH treatment and thus likely act as ACTH-preferring receptors, and the interaction between cMC3R/cMC4R and cMRAP2 was demonstrated by co-immunoprecipitation assay; (3) both cMC3R and cMC4R display constitutive activity when expressed in CHO cells, as monitored by dual-luciferase reporter assay, and cMRAP2 (and cMRAP) can modulate their constitutive activity; (4) AgRP inhibits the constitutive activity of cMC3R/cMC4R, and it also antagonizes ACTH/α-MSH action on cMC4R/cMC3R, indicating that AgRP functions as the inverse agonist and antagonist for both receptors. These findings, together with the co-expression of cMC4R, cMC3R, cMRAP2, cAgRP and cPOMC in chicken hypothalamus detected by quantitative real-time PCR, suggest that within the hypothalamus, α-MSH/ACTH, AgRP and MRAP2 may interact at the MC4R(/MC3R) interface to control energy balance. Furthermore, our data provide novel proof for the involvement of MRAP2 (and MRAP) in fine-tuning the constitutive activity and ligand sensitivity and selectivity of both MC3R and MC4R in vertebrates.
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MESH Headings
- Adrenocorticotropic Hormone/genetics
- Adrenocorticotropic Hormone/metabolism
- Agouti-Related Protein/genetics
- Agouti-Related Protein/metabolism
- Amino Acid Sequence
- Animals
- CHO Cells
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Chickens/genetics
- Chickens/metabolism
- Cloning, Molecular
- Cricetinae
- Cricetulus
- DNA, Complementary
- Gene Expression Regulation/physiology
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Melanocortin, Type 3/metabolism
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- alpha-MSH/genetics
- alpha-MSH/metabolism
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Affiliation(s)
- Jiannan Zhang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Xin Li
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Yawei Zhou
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Lin Cui
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Jing Li
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Chenlei Wu
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Yiping Wan
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Juan Li
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Yajun Wang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
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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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26
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Lu Y, Klimovich CM, Robeson KZ, Boswell W, Ríos-Cardenas O, Walter RB, Morris MR. Transcriptome assembly and candidate genes involved in nutritional programming in the swordtail fish Xiphophorus multilineatus. PeerJ 2017; 5:e3275. [PMID: 28480144 PMCID: PMC5417068 DOI: 10.7717/peerj.3275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 04/04/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Nutritional programming takes place in early development. Variation in the quality and/or quantity of nutrients in early development can influence long-term health and viability. However, little is known about the mechanisms of nutritional programming. The live-bearing fish Xiphophorus multilineatus has the potential to be a new model for understanding these mechanisms, given prior evidence of nutritional programming influencing behavior and juvenile growth rate. We tested the hypotheses that nutritional programming would influence behaviors involved in energy homeostasis as well gene expression in X. multilineatus. METHODS We first examined the influence of both juvenile environment (varied in nutrition and density) and adult environment (varied in nutrition) on behaviors involved in energy acquisition and energy expenditure in adult male X. multilineatus. We also compared the behavioral responses across the genetically influenced size classes of males. Males stop growing at sexual maturity, and the size classes of can be identified based on phenotypes (adult size and pigment patterns). To study the molecular signatures of nutritional programming, we assembled a de novo transcriptome for X. multilineatus using RNA from brain, liver, skin, testis and gonad tissues, and used RNA-Seq to profile gene expression in the brains of males reared in low quality (reduced food, increased density) and high quality (increased food, decreased density) juvenile environments. RESULTS We found that both the juvenile and adult environments influenced the energy intake behavior, while only the adult environment influenced energy expenditure. In addition, there were significant interactions between the genetically influenced size classes and the environments that influenced energy intake and energy expenditure, with males from one of the four size classes (Y-II) responding in the opposite direction as compared to the other males examined. When we compared the brains of males of the Y-II size class reared in a low quality juvenile environment to males from the same size class reared in high quality juvenile environment, 131 genes were differentially expressed, including metabolism and appetite master regulator agrp gene. DISCUSSION Our study provides evidence for nutritional programming in X. multilineatus, with variation across size classes of males in how juvenile environment and adult diet influences behaviors involved in energy homeostasis. In addition, we provide the first transcriptome of X. multilineatus, and identify a group of candidate genes involved in nutritional programming.
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Affiliation(s)
- Yuan Lu
- Molecular Bioscience Research Group, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA
| | | | - Kalen Z Robeson
- Department of Biological Sciences, Ohio University, Athens, OH, USA
| | - William Boswell
- Molecular Bioscience Research Group, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA
| | - Oscar Ríos-Cardenas
- Red de Biología Evolutiva, Instituto de Ecología A.C, Xalapa, Veracruz, Mexico
| | - Ronald B Walter
- Molecular Bioscience Research Group, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA
| | - Molly R Morris
- Department of Biological Sciences, Ohio University, Athens, OH, USA
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27
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Rønnestad I, Gomes AS, Murashita K, Angotzi R, Jönsson E, Volkoff H. Appetite-Controlling Endocrine Systems in Teleosts. Front Endocrinol (Lausanne) 2017; 8:73. [PMID: 28458653 PMCID: PMC5394176 DOI: 10.3389/fendo.2017.00073] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/27/2017] [Indexed: 12/15/2022] Open
Abstract
Mammalian studies have shaped our understanding of the endocrine control of appetite and body weight in vertebrates and provided the basic vertebrate model that involves central (brain) and peripheral signaling pathways as well as environmental cues. The hypothalamus has a crucial function in the control of food intake, but other parts of the brain are also involved. The description of a range of key neuropeptides and hormones as well as more details of their specific roles in appetite control continues to be in progress. Endocrine signals are based on hormones that can be divided into two groups: those that induce (orexigenic), and those that inhibit (anorexigenic) appetite and food consumption. Peripheral signals originate in the gastrointestinal tract, liver, adipose tissue, and other tissues and reach the hypothalamus through both endocrine and neuroendocrine actions. While many mammalian-like endocrine appetite-controlling networks and mechanisms have been described for some key model teleosts, mainly zebrafish and goldfish, very little knowledge exists on these systems in fishes as a group. Fishes represent over 30,000 species, and there is a large variability in their ecological niches and habitats as well as life history adaptations, transitions between life stages and feeding behaviors. In the context of food intake and appetite control, common adaptations to extended periods of starvation or periods of abundant food availability are of particular interest. This review summarizes the recent findings on endocrine appetite-controlling systems in fish, highlights their impact on growth and survival, and discusses the perspectives in this research field to shed light on the intriguing adaptations that exist in fish and their underlying mechanisms.
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Affiliation(s)
- Ivar Rønnestad
- Department of Biology, University of Bergen, Bergen, Norway
| | - Ana S. Gomes
- Department of Biology, University of Bergen, Bergen, Norway
| | - Koji Murashita
- Department of Biology, University of Bergen, Bergen, Norway
- Research Center for Aquaculture Systems, National Research Institute of Aquaculture, Japan Fisheries Research and Education Agency, Tamaki, Mie, Japan
| | - Rita Angotzi
- Department of Biology, University of Bergen, Bergen, Norway
| | - Elisabeth Jönsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Hélène Volkoff
- Departments of Biology and Biochemistry, Memorial University of Newfoundland, St John’s, NL, Canada
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28
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Shainer I, Buchshtab A, Hawkins TA, Wilson SW, Cone RD, Gothilf Y. Novel hypophysiotropic AgRP2 neurons and pineal cells revealed by BAC transgenesis in zebrafish. Sci Rep 2017; 7:44777. [PMID: 28317906 PMCID: PMC5357965 DOI: 10.1038/srep44777] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/13/2017] [Indexed: 11/21/2022] Open
Abstract
The neuropeptide agouti-related protein (AgRP) is expressed in the arcuate nucleus of the mammalian hypothalamus and plays a key role in regulating food consumption and energy homeostasis. Fish express two agrp genes in the brain: agrp1, considered functionally homologous with the mammalian AgRP, and agrp2. The role of agrp2 and its relationship to agrp1 are not fully understood. Utilizing BAC transgenesis, we generated transgenic zebrafish in which agrp1- and agrp2-expressing cells can be visualized and manipulated. By characterizing these transgenic lines, we showed that agrp1-expressing neurons are located in the ventral periventricular hypothalamus (the equivalent of the mammalian arcuate nucleus), projecting throughout the hypothalamus and towards the preoptic area. The agrp2 gene was expressed in the pineal gland in a previously uncharacterized subgroup of cells. Additionally, agrp2 was expressed in a small group of neurons in the preoptic area that project directly towards the pituitary and form an interface with the pituitary vasculature, suggesting that preoptic AgRP2 neurons are hypophysiotropic. We showed that direct synaptic connection can exist between AgRP1 and AgRP2 neurons in the hypothalamus, suggesting communication and coordination between AgRP1 and AgRP2 neurons and, therefore, probably also between the processes they regulate.
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Affiliation(s)
- Inbal Shainer
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Adi Buchshtab
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Thomas A. Hawkins
- The Department of Cell and Developmental Biology, Faculty of Life Sciences, University College London, London, UK
| | - Stephen W. Wilson
- The Department of Cell and Developmental Biology, Faculty of Life Sciences, University College London, London, UK
| | - Roger D. Cone
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Yoav Gothilf
- Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
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29
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Liu L, Ang KP, Elliott JAK, Kent MP, Lien S, MacDonald D, Boulding EG. A genome scan for selection signatures comparing farmed Atlantic salmon with two wild populations: Testing colocalization among outlier markers, candidate genes, and quantitative trait loci for production traits. Evol Appl 2016; 10:276-296. [PMID: 28250812 PMCID: PMC5322405 DOI: 10.1111/eva.12450] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 11/16/2016] [Indexed: 01/08/2023] Open
Abstract
Comparative genome scans can be used to identify chromosome regions, but not traits, that are putatively under selection. Identification of targeted traits may be more likely in recently domesticated populations under strong artificial selection for increased production. We used a North American Atlantic salmon 6K SNP dataset to locate genome regions of an aquaculture strain (Saint John River) that were highly diverged from that of its putative wild founder population (Tobique River). First, admixed individuals with partial European ancestry were detected using STRUCTURE and removed from the dataset. Outlier loci were then identified as those showing extreme differentiation between the aquaculture population and the founder population. All Arlequin methods identified an overlapping subset of 17 outlier loci, three of which were also identified by BayeScan. Many outlier loci were near candidate genes and some were near published quantitative trait loci (QTLs) for growth, appetite, maturity, or disease resistance. Parallel comparisons using a wild, nonfounder population (Stewiacke River) yielded only one overlapping outlier locus as well as a known maturity QTL. We conclude that genome scans comparing a recently domesticated strain with its wild founder population can facilitate identification of candidate genes for traits known to have been under strong artificial selection.
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Affiliation(s)
- Lei Liu
- Department of Integrative Biology University of Guelph Guelph ON Canada; Present address: School of Marine Sciences Ningbo University Ningbo China
| | | | | | - Matthew Peter Kent
- Department of Animal and Aquacultural Sciences (IHA) Center for Integrative Genetics (CIGENE) Norwegian University of Life Sciences Ås Norway
| | - Sigbjørn Lien
- Department of Animal and Aquacultural Sciences (IHA) Center for Integrative Genetics (CIGENE) Norwegian University of Life Sciences Ås Norway
| | - Danielle MacDonald
- Saint Andrews Biological Station Department of Fisheries and Oceans Canada Saint Andrews NB Canada
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30
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Jørgensen EH, Bernier NJ, Maule AG, Vijayan MM. Effect of long-term fasting and a subsequent meal on mRNA abundances of hypothalamic appetite regulators, central and peripheral leptin expression and plasma leptin levels in rainbow trout. Peptides 2016; 86:162-170. [PMID: 26471905 DOI: 10.1016/j.peptides.2015.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/11/2015] [Accepted: 08/14/2015] [Indexed: 01/02/2023]
Abstract
Knowledge about neuroendocrine mechanisms regulating appetite in fish, including the role of leptin, is inconclusive. We investigated leptin mRNA abundance in various tissues, plasma leptin levels and the hypothalamic gene expression of putative orexigenic (neuropeptide Y and agouti-regulated peptide) and anorexigenic (melanocortin receptor, proopiomelanocortins (POMCs), cocaine- and amphetamine-regulated transcript and corticotropin-releasing factor) neuropeptides in relation to feeding status in rainbow trout (Oncorhynchus mykiss). Blood and tissues were first (Day 1) sampled from trout that had been fed or fasted for 4 months and the day after (Day 2) from fasted fish after they had been given a large meal, and their continuously fed counterparts. The fasted fish ate vigorously when they were presented a meal. There were no differences between fed, fasted and re-fed fish in hypothalamic neuropeptide transcript levels, except for pomca1 and pomcb, which were higher in fasted fish than in fed fish at Day 1, and which, for pomcb, decreased to the level in fed fish after the meal at Day 2. Plasma leptin levels did not differ between fasted, re-fed and fed fish. A higher leptina1 transcript level was seen in the belly flap of fasted fish than in fed fish, even after re-feeding on Day 2. The data do not reveal causative roles of the investigated brain neuropeptides, or leptin, in appetite regulation. It is suggested that the elevated pomc transcript levels provide a satiety signal that reduces energy expenditure during prolonged fasting. The increase in belly flap leptin transcript with fasting, which did not decrease upon re-feeding, indicates a tissue-specific role of leptin in long-term regulation of energy homeostasis.
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Affiliation(s)
- Even H Jørgensen
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, NO-9037 Tromsø, Norway.
| | - Nicholas J Bernier
- Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Alec G Maule
- USGS, WFRC, Columbia River Research Laboratory, 5501 Cook-Underwood Rd. Cook, WA 98605, USA
| | - Mathilakath M Vijayan
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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31
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White SL, Volkoff H, Devlin RH. Regulation of feeding behavior and food intake by appetite-regulating peptides in wild-type and growth hormone-transgenic coho salmon. Horm Behav 2016; 84:18-28. [PMID: 27149948 DOI: 10.1016/j.yhbeh.2016.04.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 04/01/2016] [Accepted: 04/16/2016] [Indexed: 12/17/2022]
Abstract
Survival, competition, growth and reproductive success in fishes are highly dependent on food intake, food availability and feeding behavior and are all influenced by a complex set of metabolic and neuroendocrine mechanisms. Overexpression of growth hormone (GH) in transgenic fish can result in greatly enhanced growth rates, feed conversion, feeding motivation and food intake. The objectives of this study were to compare seasonal feeding behavior of non-transgenic wild-type (NT) and GH-transgenic (T) coho salmon (Oncorhynchus kisutch), and to examine the effects of intraperitoneal injections of the appetite-regulating peptides cholecystokinin (CCK-8), bombesin (BBS), glucagon-like peptide-1 (GLP-1), and alpha-melanocyte-stimulating hormone (α-MSH) on feeding behavior. T salmon fed consistently across all seasons, whereas NT dramatically reduced their food intake in winter, indicating the seasonal regulation of appetite can be altered by overexpression of GH in T fish. Intraperitoneal injections of CCK-8 and BBS caused a significant and rapid decrease in food intake for both genotypes. Treatment with either GLP-1 or α-MSH resulted in a significant suppression of food intake for NT but had no effect in T coho salmon. The differential response of T and NT fish to α-MSH is consistent with the melanocortin-4 receptor system being a significant pathway by which GH acts to stimulate appetite. Taken together, these results suggest that chronically increased levels of GH alter feeding regulatory pathways to different extents for individual peptides, and that altered feeding behavior in transgenic coho salmon may arise, in part, from changes in sensitivity to peripheral appetite-regulating signals.
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Affiliation(s)
- Samantha L White
- Fisheries and Oceans Canada, 4160 Marine Drive, West Vancouver, BC V7V 1N6, Canada.
| | - Helene Volkoff
- Departments of Biology and Biochemistry, Memorial University of Newfoundland, St John's, NL A1B 3X9, Canada.
| | - Robert H Devlin
- Fisheries and Oceans Canada, 4160 Marine Drive, West Vancouver, BC V7V 1N6, Canada.
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32
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The potential for disruptive selection on growth rates across genetically influenced alternative reproductive tactics. Evol Ecol 2016. [DOI: 10.1007/s10682-016-9823-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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33
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Food intake inhibition in rainbow trout induced by activation of serotonin 5-HT2C receptors is associated with increases in POMC, CART and CRF mRNA abundance in hypothalamus. J Comp Physiol B 2016; 186:313-21. [PMID: 26832922 DOI: 10.1007/s00360-016-0961-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 01/05/2016] [Accepted: 01/15/2016] [Indexed: 11/27/2022]
Abstract
In rainbow trout, the food intake inhibition induced by serotonin occurs through 5-HT2C and 5-HT1A receptors, though the mechanisms involved are still unknown. Therefore, we assessed if a direct stimulation of 5-HT2C and 5-HT1A serotonin receptors (resulting in decreased food intake in rainbow trout), affects gene expression of neuropeptides involved in the control of food intake, such as pro-opiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), corticotrophin releasing factor (CRF), and agouti-related peptide (AgRP). In a first set of experiments, the injection of the 5-HT2C receptor agonists MK212 (60 μg kg(-1) icv) and WAY 161503 (1 mg kg(-1) ip), and of the 5-HT1A receptor agonist 8-OH-DPAT (1 mg kg(-1) ip and 30 μg kg(-1) icv) induced food intake inhibition. In a second set of experiments, we observed that the injection of MK212 or WAY 161503 (1 and 3 mg kg(-1)) significantly increased hypothalamic POMC mRNA abundance. CART mRNA abundance in hypothalamus was enhanced by treatment with MK212 and unaffected by WAY 161503. The administration of the 5-HT1A receptor agonist 8-OH-DPAT did not induce any significant variation in the hypothalamic POMC or CART mRNA levels. CRF mRNA abundance was only affected by MK212 that increased hypothalamic values. Finally, hypothalamic AgRP mRNA abundance was only evaluated with the agonist 5-HT2C MK212 resulting in no significant effects. The results show that the reduction in food intake mediated by 5-HT2C receptors is associated with increases in hypothalamic POMC, CART and CRF mRNA abundance.
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34
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Gesto M, Soengas JL, Rodríguez-Illamola A, Míguez JM. Arginine vasotocin treatment induces a stress response and exerts a potent anorexigenic effect in rainbow trout, Oncorhynchus mykiss. J Neuroendocrinol 2014; 26:89-99. [PMID: 24341528 DOI: 10.1111/jne.12126] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/28/2013] [Accepted: 12/12/2013] [Indexed: 12/16/2022]
Abstract
The peptide arginine vasotocin (AVT), homologous to mammalian arginine vasopressin, is involved in many aspects of fish physiology, such as osmoregulation, regulation of biological rhythms, reproduction, metabolism or responses to stress, and the modulation of social behaviours. Because a decrease in appetite is a general response to stress in fish and other vertebrates, we investigated the role of AVT as a possible food intake regulator in fish. We used i.c.v. injections for central administration of AVT to rainbow trout (Oncorhynchus mykiss). In a first experiment, we evaluated the temporal response of food intake after AVT treatment. In a second experiment, we investigated the effects of central AVT administration on the response of typical stress markers (plasma cortisol, glucose and lactate), as well as brain serotonergic, noradrenergic and dopaminergic activity. In addition, the mRNA levels of genes involved in food intake regulation [neuropetide Y, pro-opiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART) and corticotrophin-releasing factor (CRF)] and in CRF- (CRF-binding protein) and AVT-signalling (pro-VT and AVT receptor), were also assessed after AVT treatment. Our results showed that AVT is a potent anorexigenic factor in fish. Increases of plasma cortisol and glucose after AVT treatment strongly suggest that AVT administration induced a stress response and that AVT action was mediated by hypothalamic-pituitary-interrenal axis activation, which was also supported by the increase of the serotonergic activity in trout telencephalon and hypothalamus. The increased hypothalamic levels of POMC and CART suggest that these peptides might have a role in the anorexigenic action of AVT, whereas the involvement of CRF signalling is unclear.
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Affiliation(s)
- M Gesto
- Laboratorio de Fisiología animal, Departamento de Biología Funcional y CC. de la Salud, Facultad de Biología, Universidade de Vigo, Vigo, Spain
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Shahjahan M, Kitahashi T, Parhar IS. Central pathways integrating metabolism and reproduction in teleosts. Front Endocrinol (Lausanne) 2014; 5:36. [PMID: 24723910 PMCID: PMC3971181 DOI: 10.3389/fendo.2014.00036] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/11/2014] [Indexed: 01/08/2023] Open
Abstract
Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropeptide-Y, ghrelin, pituitary adenylate cyclase-activating polypeptide, α-melanocyte stimulating hormone, melanin-concentrating hormone, cholecystokinin, 26RFamide, nesfatin, kisspeptin, and gonadotropin-inhibitory hormone. These neuropeptides are involved in the control of energy balance and reproduction either directly or indirectly. On the other hand, synthesis and release of these hypothalamic neuropeptides are regulated by metabolic signals from the gut and the adipose tissue. Furthermore, neurons producing these neuropeptides interact with each other, providing neuronal basis of the link between energy balance and reproduction. This review summarizes the advances made in our understanding of the physiological roles of the hypothalamic neuropeptides in energy balance and reproduction in teleosts, and discusses how they interact with GnRH, kisspeptin, and pituitary gonadotropins to control reproduction in teleosts.
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Affiliation(s)
- Md. Shahjahan
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
| | - Takashi Kitahashi
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
| | - Ishwar S. Parhar
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
- *Correspondence: Ishwar S. Parhar, Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya 46150, Malaysia e-mail:
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Domené S, Bumaschny VF, de Souza FSJ, Franchini LF, Nasif S, Low MJ, Rubinstein M. Enhancer turnover and conserved regulatory function in vertebrate evolution. Philos Trans R Soc Lond B Biol Sci 2013; 368:20130027. [PMID: 24218639 DOI: 10.1098/rstb.2013.0027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mutations in regulatory regions including enhancers are an important source of variation and innovation during evolution. Enhancers can evolve by changes in the sequence, arrangement and repertoire of transcription factor binding sites, but whole enhancers can also be lost or gained in certain lineages in a process of turnover. The proopiomelanocortin gene (Pomc), which encodes a prohormone, is expressed in the pituitary and hypothalamus of all jawed vertebrates. We have previously described that hypothalamic Pomc expression in mammals is controlled by two enhancers-nPE1 and nPE2-that are derived from transposable elements and that presumably replaced the ancestral neuronal Pomc regulatory regions. Here, we show that nPE1 and nPE2, even though they are mammalian novelties with no homologous counterpart in other vertebrates, nevertheless can drive gene expression specifically to POMC neurons in the hypothalamus of larval and adult transgenic zebrafish. This indicates that when neuronal Pomc enhancers originated de novo during early mammalian evolution, the newly created cis- and trans-codes were similar to the ancestral ones. We also identify the neuronal regulatory region of zebrafish pomca and confirm that it is not homologous to the mammalian enhancers. Our work sheds light on the process of gene regulatory evolution by showing how a locus can undergo enhancer turnover and nevertheless maintain the ancestral transcriptional output.
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Affiliation(s)
- Sabina Domené
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, , C1428ADN Buenos Aires, Argentina
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Gene amplification and functional diversification of melanocortin 4 receptor at an extremely polymorphic locus controlling sexual maturation in the platyfish. Genetics 2013; 195:1337-52. [PMID: 24077304 DOI: 10.1534/genetics.113.155952] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In two swordtail species of the genus Xiphophorus, the onset of puberty has been shown to be modulated at the P locus by sequence polymorphism and gene copy-number variation affecting the type 4 melanocortin hormone receptor Mc4r. The system works through the interaction of two allelic types, one encoding wild type and the other dominant-negative receptors. We have analyzed the structure and evolution of the P locus in the platyfish Xiphophorus maculatus, where as many as nine alleles of P determining the onset of sexual maturity in males and females, fecundity in females, and adult size in males are located on both the X and Y chromosomes in a region linked to the master sex-determining locus. In this species, mc4r has been amplified to up to 10 copies on both the X and Y chromosomes through recent large serial duplications. Subsequently, mc4r paralogues have diverged considerably into many different subtypes. Certain copies have acquired new untranslated regions through genomic rearrangements, and transposable element insertions and other mutations have accumulated in promoter regions, possibly explaining observed deviations from the classical mc4r transcriptional pattern. In the mc4r-coding sequence, in-frame insertions and deletions as well as nonsense and missense mutations have generated a high diversity of Mc4r-predicted proteins. Most of these variants are expressed in embryos, adults, and/or tumors. Functional receptor characterization demonstrated major divergence in pharmacological behavior for Mc4r receptors encoded by different copies of platyfish mc4r, with differences in constitutive activity as well as binding and stimulation by hormones. The high degree of allelic and copy-number variation observed between individuals can explain the high level of polymorphism for sexual maturation, fecundity, and body size in the platyfish: multiple combinations of Mc4r variants with different biochemical properties might interact to modulate the melanocortin signaling that regulates the hypothalamus-pituitary-gonadal axis.
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Schneider JE, Wise JD, Benton NA, Brozek JM, Keen-Rhinehart E. When do we eat? Ingestive behavior, survival, and reproductive success. Horm Behav 2013; 64:702-28. [PMID: 23911282 DOI: 10.1016/j.yhbeh.2013.07.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 07/21/2013] [Accepted: 07/22/2013] [Indexed: 12/13/2022]
Abstract
The neuroendocrinology of ingestive behavior is a topic central to human health, particularly in light of the prevalence of obesity, eating disorders, and diabetes. The study of food intake in laboratory rats and mice has yielded some useful hypotheses, but there are still many gaps in our knowledge. Ingestive behavior is more complex than the consummatory act of eating, and decisions about when and how much to eat usually take place in the context of potential mating partners, competitors, predators, and environmental fluctuations that are not present in the laboratory. We emphasize appetitive behaviors, actions that bring animals in contact with a goal object, precede consummatory behaviors, and provide a window into motivation. Appetitive ingestive behaviors are under the control of neural circuits and neuropeptide systems that control appetitive sex behaviors and differ from those that control consummatory ingestive behaviors. Decreases in the availability of oxidizable metabolic fuels enhance the stimulatory effects of peripheral hormones on appetitive ingestive behavior and the inhibitory effects on appetitive sex behavior, putting a new twist on the notion of leptin, insulin, and ghrelin "resistance." The ratio of hormone concentrations to the availability of oxidizable metabolic fuels may generate a critical signal that schedules conflicting behaviors, e.g., mate searching vs. foraging, food hoarding vs. courtship, and fat accumulation vs. parental care. In species representing every vertebrate taxa and even in some invertebrates, many putative "satiety" or "hunger" hormones function to schedule ingestive behavior in order to optimize reproductive success in environments where energy availability fluctuates.
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Affiliation(s)
- Jill E Schneider
- Department of Biological Sciences, Lehigh University, 111 Research Drive, Bethlehem, PA 18015, USA
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Mancebo MJ, Ceballos FC, Pérez-Maceira J, Aldegunde M. Hypothalamic neuropeptide Y (NPY) gene expression is not affected by central serotonin in the rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol A Mol Integr Physiol 2013; 166:186-90. [DOI: 10.1016/j.cbpa.2013.05.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/30/2013] [Accepted: 05/30/2013] [Indexed: 11/29/2022]
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Boonanuntanasarn S, Jangprai A, Yoshizaki G. Characterization of neuropeptide Y in snakeskin gourami and the change in its expression due to feeding status and melanocortin 4 receptor expression. Gen Comp Endocrinol 2012; 179:184-95. [PMID: 22898434 DOI: 10.1016/j.ygcen.2012.07.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/22/2012] [Accepted: 07/26/2012] [Indexed: 11/17/2022]
Abstract
In this study, we characterized the neuropeptide Y (NPY) mRNA in snakeskin gourami (Trichogaster pectoralis) (TpNPY). TpNPY displayed characteristics typical of previously reported NPYs, and it exhibited a high degree of homology with the NPY proteins of other vertebrates. A phylogenetic analysis demonstrated that TpNPY was closely related to the NPYs found in the acanthomorpha and salmoniformes fish species. TpNPY was found to be ubiquitously expressed in all brain regions when assessed by real-time RT-PCR and in situ hybridization. In addition, a graded expression level of TpNPY was observed in peripheral tissues; for example, a moderate level of TpNPY was found in the gills, liver, kidney, stomach, intestine, spleen and gonads, while a low level of TpNPY was found in the muscle. The change in expression of TpNPY with respect to daily feeding habits was investigated in distinct brain regions, including the telencephalon, mesencephalon, metencephalon, and diencephalon. Fluctuations in the expression level of TpNPY were observed for a 24h post-prandial period. Except for the telencephalon, a reduction in TpNPY expression was found after a meal, while a peak level of TpNPY was observed 1h before the scheduled breakfast. Furthermore, there was a positive correlation between TpNPY and TpMC4R in the telencephalon and diencephalon throughout the circadian feeding cycle, which suggests that there is a connection between the function of NPY and the melanocortin system for the regulation of daily feeding. Fish brains were incubated with an MC4R antagonist (i.e., HS024), and the expression of TpNPY and TpMC4R was measured. Interestingly, there was a significant relationship between the expression of TpNPY and TpMC4R under the effects of HS024, which demonstrates that there are interactions between MC4R and NPY, particularly in a hyperphagic state.
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Affiliation(s)
- Surintorn Boonanuntanasarn
- School of Animal Production Technology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Muang, Nakhon Ratchasima 30000, Thailand.
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Zhang C, Forlano PM, Cone RD. AgRP and POMC neurons are hypophysiotropic and coordinately regulate multiple endocrine axes in a larval teleost. Cell Metab 2012; 15:256-64. [PMID: 22245570 PMCID: PMC3332529 DOI: 10.1016/j.cmet.2011.12.014] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 11/23/2011] [Accepted: 12/23/2011] [Indexed: 11/18/2022]
Abstract
Plasticity in growth and reproductive behavior is found in many vertebrate species, but is common in male teleost fish. Typically, "bourgeois" males are considerably larger and defend breeding territories while "parasitic" variants are small and use opportunistic breeding strategies. The P locus mediates this phenotypic variation in Xiphophorus and encodes variant alleles of the melanocortin-4 receptor (MC4R). However, deletion of the MC4R has modest effects on somatic growth and reproduction in mammals, suggesting a fundamental difference in the neuroendocrine function of central melanocortin signaling in teleosts. Here we show in a teleost that the hypothalamic pro-opiomelanocortin and AgRP neurons are hypophysiotropic, projecting to the pituitary to coordinately regulate multiple pituitary hormones. Indeed, AgRP-mediated suppression of MC4R appears essential for early larval growth. This identifies the mechanism by which the central melanocortin system coordinately regulates growth and reproduction in teleosts and suggests it is an important anatomical substrate for evolutionary adaptation.
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Affiliation(s)
- Chao Zhang
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Department of Cell and Developmental Biology, Oregon Health Science University, Portland, OR 97239
| | - Paul M. Forlano
- Department of Biology and The Aquatic Research and Environmental Assessment Center, Brooklyn College of The City University of New York, Brooklyn, NY 11210
| | - Roger D. Cone
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Cerdá-Reverter JM, Agulleiro MJ, R RG, Sánchez E, Ceinos R, Rotllant J. Fish melanocortin system. Eur J Pharmacol 2011; 660:53-60. [DOI: 10.1016/j.ejphar.2010.10.108] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Revised: 09/30/2010] [Accepted: 10/12/2010] [Indexed: 12/26/2022]
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Abstract
The melanocortin-4 receptor (MC4R) was cloned in 1993 by degenerate PCR; however, its function was unknown. Subsequent studies suggest that the MC4R might be involved in regulating energy homeostasis. This hypothesis was confirmed in 1997 by a series of seminal studies in mice. In 1998, human genetic studies demonstrated that mutations in the MC4R gene can cause monogenic obesity. We now know that mutations in the MC4R are the most common monogenic form of obesity, with more than 150 distinct mutations reported thus far. This review will summarize the studies on the MC4R, from its cloning and tissue distribution to its physiological roles in regulating energy homeostasis, cachexia, cardiovascular function, glucose and lipid homeostasis, reproduction and sexual function, drug abuse, pain perception, brain inflammation, and anxiety. I will then review the studies on the pharmacology of the receptor, including ligand binding and receptor activation, signaling pathways, as well as its regulation. Finally, the pathophysiology of the MC4R in obesity pathogenesis will be reviewed. Functional studies of the mutant MC4Rs and the therapeutic implications, including small molecules in correcting binding and signaling defect, and their potential as pharmacological chaperones in rescuing intracellularly retained mutants, will be highlighted.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology, Auburn University, Alabama 36849-5519, USA.
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Kittilsen S, Schjolden J, Beitnes-Johansen I, Shaw JC, Pottinger TG, Sørensen C, Braastad BO, Bakken M, Overli O. Melanin-based skin spots reflect stress responsiveness in salmonid fish. Horm Behav 2009; 56:292-8. [PMID: 19539629 DOI: 10.1016/j.yhbeh.2009.06.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 06/10/2009] [Accepted: 06/11/2009] [Indexed: 12/16/2022]
Abstract
Within animal populations, genetic, epigenetic and environmental factors interact to shape individual neuroendocrine and behavioural profiles, conferring variable vulnerability to stress and disease. It remains debated how alternative behavioural syndromes and stress coping styles evolve and are maintained by natural selection. Here we show that individual variation in stress responsiveness is reflected in the visual appearance of two species of teleost fish; rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Salmon and trout skin vary from nearly immaculate to densely spotted, with black spots formed by eumelanin-producing chromatophores. In rainbow trout, selection for divergent hypothalamus-pituitary-interrenal responsiveness has led to a change in dermal pigmentation patterns, with low cortisol-responsive fish being consistently more spotted. In an aquaculture population of Atlantic salmon individuals with more spots showed a reduced physiological and behavioural response to stress. Taken together, these data demonstrate a heritable behavioural-physiological and morphological trait correlation that may be specific to alternative coping styles. This observation may illuminate the evolution of contrasting coping styles and behavioural syndromes, as occurrence of phenotypes in different environments and their response to selective pressures can be precisely and easily recorded.
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Affiliation(s)
- S Kittilsen
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, N-1432, As, Norway.
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Chapter 6 Regulation And Contribution Of The Corticotropic, Melanotropic And Thyrotropic Axes To The Stress Response In Fishes. FISH PHYSIOLOGY 2009. [DOI: 10.1016/s1546-5098(09)28006-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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