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Tong H, Shao G, Wang L, Li J, Wang T, Zhang L, Lv Y, Ye F, Fu C, Jin Y. Association of a single amino acid replacement with dorsal pigmentation in a lizard from the Qinghai-Tibetan Plateau. Int J Biol Macromol 2023; 242:124907. [PMID: 37230451 DOI: 10.1016/j.ijbiomac.2023.124907] [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: 02/15/2023] [Revised: 05/08/2023] [Accepted: 05/13/2023] [Indexed: 05/27/2023]
Abstract
Reptiles can evolve adaptive colors in different environments, but relatively little is known about the genetic mechanisms. Here, we identified the MC1R gene and its association with intraspecific color variation in the lizard Phrynocephalus erythrurus. Analysis of the MC1R sequence in 143 individuals from dark South Qiangtang Plateau (SQP) and light North Qiangtang plateau (NQP) populations, revealed two amino acid sites that showed significant differences in frequency between two areas. One SNP, corresponding to Glu183Lys residue, was found to be a highly significant outlier and differentially fixed for SQP and NQP populations. This residue is located in an extracellular area in the second small extracellular loop within the secondary structure of MC1R, which represents an "attachment pocket" part of the 3D structure. Cytological expression of MC1R alleles with the Glu183Lys replacement showed a 39 % increase in intracellular agonist-induced cyclic AMP levels and a 23.18 % greater cell surface expression of MC1R protein in the SQP relative to the NQP allele. Further in silico 3D modeling and in vitro binding experiments indicated a higher MC1R-α-MSH binding for the SQP allele, and elevated melanin synthesis. We provide an overview of how a single amino acid replacement leads to fundamental changes in MC1R function, and hence shapes variation in dorsal pigmentation in lizards from different environments.
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Affiliation(s)
- Haojie Tong
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Gang Shao
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Leijie Wang
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Jiasheng Li
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Tao Wang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Lun Zhang
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yudie Lv
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China
| | - Fei Ye
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Caiyun Fu
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yuanting Jin
- College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China.
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Zolghadri S, Beygi M, Mohammad TF, Alijanianzadeh M, Pillaiyar T, Garcia-Molina P, Garcia-Canovas F, Luis Munoz-Munoz J, Akbar Saboury A. Targeting Tyrosinase in Hyperpigmentation: Current Status, Limitations and Future Promises. Biochem Pharmacol 2023; 212:115574. [PMID: 37127249 DOI: 10.1016/j.bcp.2023.115574] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/03/2023]
Abstract
Hyperpigmentation is a common and distressing dermatologic condition. Since tyrosinase (TYR) plays an essential role in melanogenesis, its inhibition is considered a logical approach along with other therapeutic methods to prevent the accumulation of melanin in the skin. Thus, TYR inhibitors are a tempting target as the medicinal and cosmetic active agents of hyperpigmentation disorder. Among TYR inhibitors, hydroquinone is a traditional lightening agent that is commonly used in clinical practice. However, despite good efficacy, prolonged use of hydroquinone is associated with side effects. To overcome these shortcomings, new approaches in targeting TYR and treating hyperpigmentation are desperately requiredessentialneeded. In line with this purpose, several non-hydroquinone lightening agents have been developed and suggested as hydroquinone alternatives. In addition to traditional approaches, nanomedicine and nanotheranostic platforms have been recently proposed in the treatment of hyperpigmentation. In this review, we discuss the available strategies for the management of hyperpigmentation with a focus on TYR inhibition. In addition, alternative treatment options to hydroquinone are discussed. Finally, we present nano-based strategies to improve the therapeutic effect of drugs prescribed to patients with skin disorders.
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Affiliation(s)
- Samaneh Zolghadri
- Department of Biology, Jahrom Branch, Islamic Azad University, Jahrom, Iran.
| | - Mohammad Beygi
- Department of Agricultural Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran
| | | | - Mahdi Alijanianzadeh
- Department of Cell & Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Thanigaimalai Pillaiyar
- Institute of Pharmacy, Pharmaceutical/Medicinal Chemistry and Tuebingen Center for Academic Drug Discovery, Eberhard Karls University Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany
| | - Pablo Garcia-Molina
- GENZ-Group of Research on Enzymology, Department of Biochemistry and Molecular Biology-A, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain
| | - Francisco Garcia-Canovas
- GENZ-Group of Research on Enzymology, Department of Biochemistry and Molecular Biology-A, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Espinardo, Murcia, Spain
| | - Jose Luis Munoz-Munoz
- Microbial Enzymology Lab, Department of Applied Sciences, Ellison Building A, University of Northumbria, Newcastle Upon Tyne, UK
| | - Ali Akbar Saboury
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
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Zhou BB, Liu D, Qian JC, Tan RX. Vegetable-derived indole enhances the melanoma-treating efficacy of chemotherapeutics. Phytother Res 2022; 36:4278-4292. [PMID: 35883268 DOI: 10.1002/ptr.7565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 11/08/2022]
Abstract
Food-drug interaction is an important but overlooked issue. For example, little is known concerning whether or not the chemotherapy of cancers is affected by the well-defined dietary chemicals such as 2-(indol-3-ylmethyl)-3,3'-diindolylmethane (LTr1) derived from daily consumed cruciferous vegetables. This work, inspired by the described melanogenesis reduction by certain indoles, presents that LTr1 mitigates the melanogenesis and thus potentiates the in vitro and in vivo anti-melanoma effectiveness of different chemotherapeutic agents including dacarbazine, vemurafenib, and sorafenib. In B16 melanoma cells, LTr1 was shown to inhibit the melanogenesis by acting towards the regulatory (R) subunit of protein kinase A (PRKAR1a) associated with the phosphorylation of cAMP-response element binding protein (CREB). This allows LTr1 to reduce the expression of melanogenesis-related enzymes such as tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), and tyrosinase-related protein 2 (TYRP2). Furthermore, LTr1 was addressed to bind to the aryl hydrocarbon receptor (AhR) and up-regulate the expression of CYP1A1 encoding cytochrome P450 1A1, leading to the escalation of reactive oxygen species (ROS) level. The increased ROS generation promotes the cysteine-to-cystine transformation to inhibit the pheomelanogenesis in melanomas. Collectively, the work identifies LTr1 as a new melanogenesis inhibitor that modulates the PKA/CREB/MITF and AhR/CYP1A1/ROS pathways, thereby providing a new option for (re)sensitizing melanomas to chemotherapeutics.
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Affiliation(s)
- Bei Bei Zhou
- State Key Laboratory Cultivation Base for Traditional Chinese Medicine Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Dan Liu
- State Key Laboratory Cultivation Base for Traditional Chinese Medicine Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jia Cheng Qian
- State Key Laboratory Cultivation Base for Traditional Chinese Medicine Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Ren Xiang Tan
- State Key Laboratory Cultivation Base for Traditional Chinese Medicine Quality and Efficacy, Nanjing University of Chinese Medicine, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, Institute of Functional Biomolecules, Nanjing University, Nanjing, China
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Galván I, Schwartz TS, Garland T. Evolutionary physiology at 30+: Has the promise been fulfilled?: Advances in Evolutionary Physiology: Advances in Evolutionary Physiology. Bioessays 2021; 44:e2100167. [PMID: 34802161 DOI: 10.1002/bies.202100167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 12/19/2022]
Abstract
Three decades ago, interactions between evolutionary biology and physiology gave rise to evolutionary physiology. This caused comparative physiologists to improve their research methods by incorporating evolutionary thinking. Simultaneously, evolutionary biologists began focusing more on physiological mechanisms that may help to explain constraints on and trade-offs during microevolutionary processes, as well as macroevolutionary patterns in physiological diversity. Here we argue that evolutionary physiology has yet to reach its full potential, and propose new avenues that may lead to unexpected advances. Viewing physiological adaptations in wild animals as potential solutions to human diseases offers enormous possibilities for biomedicine. New evidence of epigenetic modifications as mechanisms of phenotypic plasticity that regulate physiological traits may also arise in coming years, which may also represent an overlooked enhancer of adaptation via natural selection to explain physiological evolution. Synergistic interactions at these intersections and other areas will lead to a novel understanding of organismal biology.
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Affiliation(s)
- Ismael Galván
- Department of Evolutionary Ecology, National Museum of Natural Sciences, CSIC, Madrid, Spain
| | - Tonia S Schwartz
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Theodore Garland
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, California, USA
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Kulikova IV. Molecular Mechanisms and Gene Regulation of Melanic Plumage Coloration in Birds. RUSS J GENET+ 2021. [DOI: 10.1134/s102279542108007x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zhou S, Zeng H, Huang J, Lei L, Tong X, Li S, Zhou Y, Guo H, Khan M, Luo L, Xiao R, Chen J, Zeng Q. Epigenetic regulation of melanogenesis. Ageing Res Rev 2021; 69:101349. [PMID: 33984527 DOI: 10.1016/j.arr.2021.101349] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 02/07/2023]
Abstract
Melanogenesis is a complex process in which melanin is synthesized in melanocytes and transported to keratinocytes, which involves multiple genes and signaling pathways. Epigenetics refers to the potential genetic changes that affect gene expression without involving changes in the original sequence of DNA nucleotides. DNA methylation regulates the expression of key genes such as tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), dopachrome tautomerase (DCT) and microphthalmia-associated transcription factor (MITF), as well as paracrine factors such as stem cell factor (SCF) and endothelin-1 (ET-1) in melanogenesis. Potential DNA methylation sites are present in the genes of melanogenesis-related signaling pathways such as "Wnt", "PI3K/Akt/CREB" and "MAPK". H3K27 acetylation is abundant in melanogenesis-related genes. Both the upstream activation and downstream regulation of MITF depend on histone acetyltransferase CBP/p300, and pH-induced H3K27 acetylation may be the amplifying mechanism of MITF's effect. HDAC1 and HDAC10 catalyze histone deacetylation of melanogenesis-related gene promoters. Chromatin remodelers SWI/SNF complex and ISWI complex use the energy of ATP hydrolysis to rearrange nucleosomes, while their active subunits BRG1, BRM and BPTF, act as activators and cofactors of MITF. MicroRNAs (miRNAs) can directly target a large number of melanogenesis-related genes, while long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) regulate melanogenesis in a variety of ways. Interactions exist among the epigenetic mechanisms of melanogenesis. For example, the methyl CpG binding domain protein 2 (MeCP2) links DNA methylation, histone deacetylation, and histone methylation. Epigenetic-based therapy provides novel opportunities for treating dermatoses that are caused by pigmentation disturbances. This review summarizes the epigenetic regulation mechanisms of melanogenesis, and examines the pathogenesis and treatment of epigenetics in pigmentation disorders.
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Manganelli M, Guida S, Ferretta A, Pellacani G, Porcelli L, Azzariti A, Guida G. Behind the Scene: Exploiting MC1R in Skin Cancer Risk and Prevention. Genes (Basel) 2021; 12:1093. [PMID: 34356109 PMCID: PMC8305013 DOI: 10.3390/genes12071093] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 02/06/2023] Open
Abstract
Melanoma and non-melanoma skin cancers (NMSCs) are the most frequent cancers of the skin in white populations. An increased risk in the development of skin cancers has been associated with the combination of several environmental factors (i.e., ultraviolet exposure) and genetic background, including melanocortin-1 receptor (MC1R) status. In the last few years, advances in the diagnosis of skin cancers provided a great impact on clinical practice. Despite these advances, NMSCs are still the most common malignancy in humans and melanoma still shows a rising incidence and a poor prognosis when diagnosed at an advanced stage. Efforts are required to underlie the genetic and clinical heterogeneity of melanoma and NMSCs, leading to an optimization of the management of affected patients. The clinical implications of the impact of germline MC1R variants in melanoma and NMSCs' risk, together with the additional risk conferred by somatic mutations in other peculiar genes, as well as the role of MC1R screening in skin cancers' prevention will be addressed in the current review.
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Affiliation(s)
- Michele Manganelli
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari-“Aldo Moro”, 70125 Bari, Italy; (M.M.); (A.F.)
- DMMT-Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
| | - Stefania Guida
- Department of Surgical-Medical-Dental and Morphological Science with Interest Transplant-Oncological and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy;
| | - Anna Ferretta
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari-“Aldo Moro”, 70125 Bari, Italy; (M.M.); (A.F.)
| | - Giovanni Pellacani
- Department of Clinical Internal, Anesthesiological and Cardiovascular Sciences, Dermatology Clinic, Sapienza University of Rome, 00161 Rome, Italy;
| | - Letizia Porcelli
- Laboratory of Experimental Pharmacology, IRCCS Istituto Tumori Giovanni Paolo II, 70124 Bari, Italy; (L.P.); (A.A.)
| | - Amalia Azzariti
- Laboratory of Experimental Pharmacology, IRCCS Istituto Tumori Giovanni Paolo II, 70124 Bari, Italy; (L.P.); (A.A.)
| | - Gabriella Guida
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari-“Aldo Moro”, 70125 Bari, Italy; (M.M.); (A.F.)
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Slc7a11 downregulation is rapidly reversed after cessation of competitive social stress in zebra finches. Mol Biol Rep 2021; 48:3007-3010. [PMID: 33740177 DOI: 10.1007/s11033-021-06256-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
Gene expression can be modulated by epigenetic modifications, which may lead to a rapid adaptation to environmental stress. After stress cessation, changes in gene expression could be reversed, which would allow organisms to maintain their phenotype under transient environments, but this mechanism is poorly understood. Social stress downregulates a gene directly involved in pheomelanin synthesis (Slc7a11) by changing DNA m5C levels, avoiding cellular damage caused by stress. We thus investigated if Slc7a11 expression is reversed in melanocytes of growing flank feathers to avoid changes in the pigmentation phenotype. We measured the expression level of Slc7a11 at three time points: before stress exposure, immediately after stress exposure and six weeks after stress cessation in 37 male zebra finches (Taeniopygia guttata). No differences in Slc7a11 expression were detected between birds exposed to stress and controls six weeks after stress elimination, indicating that stress removal led to a cessation of Slc7a11 downregulation. Reversibility in Slc7a11 expression, probably mediated by reversible changes in DNA methylation, may thus avoid altering the pigmentation phenotype during transient stressful conditions. This is one of the few studies in vertebrates supporting the idea that reversible gene expression responses allow organisms adapting to changing environmental conditions.
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de Oliveira Neves AC, Galván I. Models for human porphyrias: Have animals in the wild been overlooked?: Some birds and mammals accumulate significant amounts of porphyrins in the body without showing the injurious symptoms observed in human porphyrias. Bioessays 2020; 42:e2000155. [PMID: 33155299 DOI: 10.1002/bies.202000155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/27/2020] [Indexed: 11/06/2022]
Abstract
Humans accumulate porphyrins in the body mostly during the course of porphyrias, diseases caused by defects in the enzymes of the heme biosynthesis pathway and that produce acute attacks, skin lesions and liver cancer. In contrast, some wild mammals and birds are adapted to accumulate porphyrins without injurious consequences. Here we propose viewing such physiological adaptations as potential solutions to human porphyrias, and suggest certain wild animals as models. Given the enzymatic activity and/or the patterns of porphyrin excretion and accumulation, the fox squirrel, the great bustard and the Eurasian eagle owl may constitute overlooked models for different porphyrias. The Harderian gland of rodents, where large amounts of porphyrins are synthesized, presents an underexplored potential for understanding the carcinogenic/toxic effect of porphyrin accumulation. Investigating how these animals avoid porphyrin pathogenicity may complement the use of laboratory models for porphyrias and provide new insights into the treatment of these disorders.
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Affiliation(s)
| | - Ismael Galván
- Department of Evolutionary Ecology, Doñana Biological Station, CSIC, Sevilla, 41092, Spain
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Rodríguez-Martínez S, Galván I. A source of exogenous oxidative stress improves oxidative status and favors pheomelanin synthesis in zebra finches. Comp Biochem Physiol C Toxicol Pharmacol 2020; 228:108667. [PMID: 31712186 DOI: 10.1016/j.cbpc.2019.108667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/25/2019] [Accepted: 11/05/2019] [Indexed: 11/22/2022]
Abstract
Some organisms can modulate gene expression to trigger physiological responses that help adapt to environmental stress. The synthesis of the pigment pheomelanin in melanocytes seems to be one of these responses, as it may contribute to cellular homeostasis. We experimentally induced environmental oxidative stress in male zebra finches Taeniopygia guttata by the administration of the herbicide diquat dibromide during feather growth to test if the expression of genes involved in pheomelanin synthesis shows epigenetic lability. As pheomelanin synthesis implies decreasing the availability of the main cellular antioxidant (glutathione), it is expected to cause oxidative stress unless a protective mechanism limits pheomelanin synthesis and thus favors the antioxidant capacity. However, diquat exposure did not only improve the antioxidant capacity of birds, but also upregulated the expression of a gene (AGRP) that promotes pheomelanin synthesis in feather melanocytes, leading to the development of darker plumage coloration. No changes in the expression of other genes involved in pheomelanin synthesis (Slc7a11, Slc45a2, MC1R, ASIP and CTNS) were detected. DNA methylation levels only changed in MC1R, suggesting that epigenetic modifications other than changes in methylation may regulate AGRP expression lability. Our results suggest that exogenous oxidative stress induced a hormetic response that enhanced the oxidative status of birds and, consequently, promoted pheomelanin-based pigmentation, supporting the idea that birds adjust pheomelanin synthesis to their oxidative stress conditions.
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Affiliation(s)
| | - Ismael Galván
- Departamento de Ecología Evolutiva, Estación Biológica de Doñana, CSIC, Sevilla, Spain
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Pheomelanin-based coloration is related to individual quality and oxidative stress in blue petrels. Evol Ecol 2019. [DOI: 10.1007/s10682-019-10010-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Rodríguez-Martínez S, Galván I. Exposure to a competitive social environment activates an epigenetic mechanism that limits pheomelanin synthesis in zebra finches. Mol Ecol 2019; 28:3698-3708. [PMID: 31290207 DOI: 10.1111/mec.15171] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/07/2019] [Accepted: 06/17/2019] [Indexed: 12/17/2022]
Abstract
Competitive environments promote high testosterone levels, produce oxidative stress and, consequently, impair cellular homeostasis. The regulation of genes involved in the synthesis of the pigment pheomelanin in melanocytes seems to help to maintain homeostasis against environmental oxidative stress. Here, we experimentally increased social interactions in some zebra finch (Taeniopygia guttata) males by keeping them in groups of six birds during feather growth, while others were kept alone, to test if melanocytes show epigenetic lability under a competitive social environment. As these changes may depend on the oxidative status, we administrated buthionine sulfoximine (BSO) to decrease the antioxidant capacity of some birds. The competitive environment downregulated a gene involved in pheomelanin synthesis (Slc7a11) by changing the level of DNA methylation in feather melanocytes. In other genes involved in pheomelanin synthesis (Slc45a2, MC1R and AGRP), DNA methylation was also affected, but no changes in expression were detected. Exposure to the competitive environment did not affect systemic oxidative stress and damage, indicating that a protective epigenetic mechanism that changes the expression of Slc7a11 may have been activated. However, no changes to the pigmentation phenotype of birds were found, probably due to the short duration or low intensity of the competitive environment. BSO treatment did not affect the epigenetic mechanism, suggesting that the antioxidant capacity of birds was high enough to deal with the competitive environment. An epigenetic mechanism limiting pheomelanin synthesis therefore becomes activated under exposure to a competitive environment in male zebra finches, which may help to avoid damage caused by competitive interactions.
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Affiliation(s)
| | - Ismael Galván
- Departamento de Ecología Evolutiva, Estación Biológica de Doñana, CSIC, Sevilla, Spain
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