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Gauthier M, Defrance J, Jumarie C, Vulliet E, Garric J, Boily M, Geffard O. Disruption of oogenesis and molting by methoprene and glyphosate in Gammarus fossarum: involvement of retinoic acid? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:86060-86071. [PMID: 37394563 DOI: 10.1007/s11356-023-28327-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/14/2023] [Indexed: 07/04/2023]
Abstract
In the last decade, the freshwater amphipod Gammarus fossarum proved to be a promising sentinel species in active biomonitoring programs to assess the effects of environmental contamination on non-target organisms. Given that the highly conserved retinoid (RETs) metabolism supports many biological functions and is perturbed by xenobiotics and used as biomarker for vertebrates, we explored the RETs functions in the crustacean model Gammarus fossarum. More specifically, we studied the implication of all -trans retinoic acid (atRA) in the reproduction (embryo, oocyte, and juvenile production) and development (success and delay of molting) by exposing G. fossarum females to atRA and citral (CIT), a known inhibitor of RA synthesis. In parallel, we exposed gammarids to methoprene (MET) and glyphosate (GLY), two pesticides suspected to interfere with atRA metabolism and signaling and frequently found in water systems. After 14 days of exposure, atRA, CIT, and MET reduced the number of oocytes, whereas only MET caused a reduced number of embryos. After 44 days, MET and GLY showed a tendency to decrease juvenile production. The duration of the molting cycle increased following the exposures to atRA and MET, while the treatment with CIT caused a typical endocrine disruptive inverted U-shaped curve. The exposure to GLY led to increased duration of the molting cycle at the lowest concentrations and lowered molting success at the highest concentration tested. This study highlights for the first time the implication of RA in the oogenesis and molting of G. fossarum and suggests that it may be a potential mediator of MET-induced effects on these processes. This study adds to the comprehension of the reproductive and developmental control in G. fossarum and opens new research avenues to study the effects of xenobiotics on the RET system in this sentinel species. Ultimately, our study will drive the development of RET-based biomarkers for non-target aquatic invertebrates exposed to xenobiotics.
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Affiliation(s)
- Maxime Gauthier
- Unité de Recherche RiverLy Ecotoxicology Laboratory, INRAE, 5, Rue de La Doua C.S. 20244, 69625, Villeurbanne Cedex, France
- Université du Québec À Montréal (UQAM), Département Des Sciences Biologiques, 141, Avenue du Président-Kennedy, C.P. 8888, Succursale Centre-Ville, Montréal, Québec, H3C 3P8, Canada
| | - Jérémy Defrance
- Unité de Recherche RiverLy Ecotoxicology Laboratory, INRAE, 5, Rue de La Doua C.S. 20244, 69625, Villeurbanne Cedex, France
- École Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Univ. de Lyon, 15, Parvis René Descartes, 69342, Lyon Cedex 07, France
| | - Catherine Jumarie
- Université du Québec À Montréal (UQAM), Département Des Sciences Biologiques, 141, Avenue du Président-Kennedy, C.P. 8888, Succursale Centre-Ville, Montréal, Québec, H3C 3P8, Canada
| | - Emmanuelle Vulliet
- Univ. Lyon, CNRS, Université Claude Bernard Lyon 1, Institut Des Sciences Analytiques, UMR 5280, 5, Rue de La Doua, 69100, Villeurbanne, France
| | - Jeanne Garric
- Unité de Recherche RiverLy Ecotoxicology Laboratory, INRAE, 5, Rue de La Doua C.S. 20244, 69625, Villeurbanne Cedex, France
| | - Monique Boily
- Université du Québec À Montréal (UQAM), Département Des Sciences Biologiques, 141, Avenue du Président-Kennedy, C.P. 8888, Succursale Centre-Ville, Montréal, Québec, H3C 3P8, Canada
| | - Olivier Geffard
- Unité de Recherche RiverLy Ecotoxicology Laboratory, INRAE, 5, Rue de La Doua C.S. 20244, 69625, Villeurbanne Cedex, France.
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Wang J, Chen X, Hou X, Wang J, Yue W, Huang S, Xu G, Yan J, Lu G, Hofreiter M, Li C, Wang C. "Omics" data unveil early molecular response underlying limb regeneration in the Chinese mitten crab, Eriocheir sinensis. SCIENCE ADVANCES 2022; 8:eabl4642. [PMID: 36112682 PMCID: PMC9481118 DOI: 10.1126/sciadv.abl4642] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/01/2022] [Indexed: 05/22/2023]
Abstract
Limb regeneration is a fascinating and medically interesting trait that has been well preserved in arthropod lineages, particularly in crustaceans. However, the molecular mechanisms underlying arthropod limb regeneration remain largely elusive. The Chinese mitten crab Eriocheir sinensis shows strong regenerative capacity, a trait that has likely allowed it to become a worldwide invasive species. Here, we report a chromosome-level genome of E. sinensis as well as large-scale transcriptome data during the limb regeneration process. Our results reveal that arthropod-specific genes involved in signal transduction, immune response, histone methylation, and cuticle development all play fundamental roles during the regeneration process. Particularly, Innexin2-mediated signal transduction likely facilitates the early stage of the regeneration process, while an effective crustacean-specific prophenoloxidase system (ProPo-AS) plays crucial roles in the initial immune response. Collectively, our findings uncover novel genetic pathways pertaining to arthropod limb regeneration and provide valuable resources for studies on regeneration from a comparative perspective.
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Affiliation(s)
- Jun Wang
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
| | - Xiaowen Chen
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
| | - Xin Hou
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
| | - Jingan Wang
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
| | - Wucheng Yue
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
| | - Shu Huang
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
| | - Gangchun Xu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization certified by the Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Jizhou Yan
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
| | - Guoqing Lu
- Department of Biology, University of Nebraska at Omaha, Omaha, NE 68182, USA
| | - Michael Hofreiter
- Evolutionary Adaptive Genomics, Institute of Biochemistry and Biology, Faculty of Science, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
- Corresponding author. Email (M.H.); (C.L.); (C.W.)
| | - Chenhong Li
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
- Corresponding author. Email (M.H.); (C.L.); (C.W.)
| | - Chenghui Wang
- Key Laboratory of Freshwater Aquatic Genetic Resources certified by the Ministry of Agriculture and Rural Affairs/National Demonstration Center for Experimental Fisheries Science Education/Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China
- Corresponding author. Email (M.H.); (C.L.); (C.W.)
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Johnson A, de Hoog E, Tolentino M, Nasser T, Spencer GE. Pharmacological evidence for the role of RAR in axon guidance and embryonic development of a protostome species. Genesis 2019; 57:e23301. [PMID: 31038837 DOI: 10.1002/dvg.23301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/07/2019] [Accepted: 04/08/2019] [Indexed: 01/26/2023]
Abstract
Retinoic acid (RA), the active metabolite of vitamin A, functions through nuclear receptors, one of which is the retinoic acid receptor (RAR). Though the RAR is essential for various aspects of vertebrate development, little is known about the role of RAR in nonchordate invertebrates. Here, we examined the potential role of an invertebrate RAR in mediating chemotropic effects of retinoic acid. The RAR of the protostome Lymnaea stagnalis is present in the growth cones of regenerating cultured motorneurons, and a synthetic RAR agonist (EC23), was able to mimic the effects of retinoic acid in inducing growth cone turning. We also examined the ability of the natural retinoids, all-trans RA and 9-cis RA, as well as the synthetic RAR agonists, to disrupt embryonic development in Lymnaea. Developmental defects included delays in embryo hatching, arrested eye, and shell development, as well as more severe abnormalities such as halted development. Developmental defects induced by some (but not all) synthetic RAR agonists were found to mimic those induced by addition of high concentrations of the natural retinoid isomers. These pharmacological data support a possible physiological role for the RAR in axon guidance and embryonic development of an invertebrate protostome species.
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Affiliation(s)
- Alysha Johnson
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Eric de Hoog
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Michael Tolentino
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Tamara Nasser
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Gaynor E Spencer
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada
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New Insights Into the Roles of Retinoic Acid Signaling in Nervous System Development and the Establishment of Neurotransmitter Systems. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 330:1-84. [PMID: 28215529 DOI: 10.1016/bs.ircmb.2016.09.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Secreted chiefly from the underlying mesoderm, the morphogen retinoic acid (RA) is well known to contribute to the specification, patterning, and differentiation of neural progenitors in the developing vertebrate nervous system. Furthermore, RA influences the subtype identity and neurotransmitter phenotype of subsets of maturing neurons, although relatively little is known about how these functions are mediated. This review provides a comprehensive overview of the roles played by RA signaling during the formation of the central and peripheral nervous systems of vertebrates and highlights its effects on the differentiation of several neurotransmitter systems. In addition, the evolutionary history of the RA signaling system is discussed, revealing both conserved properties and alternate modes of RA action. It is proposed that comparative approaches should be employed systematically to expand our knowledge of the context-dependent cellular mechanisms controlled by the multifunctional signaling molecule RA.
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Carter CJ, Rand C, Mohammad I, Lepp A, Vesprini N, Wiebe O, Carlone R, Spencer GE. Expression of a retinoic acid receptor (RAR)-like protein in the embryonic and adult nervous system of a protostome species. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 324:51-67. [DOI: 10.1002/jez.b.22604] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 10/18/2014] [Indexed: 01/08/2023]
Affiliation(s)
| | - Christopher Rand
- Department of Biological Sciences; Brock University; Ontario Canada
| | - Imtiaz Mohammad
- Department of Biological Sciences; Brock University; Ontario Canada
| | - Amanda Lepp
- Department of Biological Sciences; Brock University; Ontario Canada
| | | | - Olivia Wiebe
- Department of Biological Sciences; Brock University; Ontario Canada
| | - Robert Carlone
- Department of Biological Sciences; Brock University; Ontario Canada
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Gutierrez-Mazariegos J, Schubert M, Laudet V. Evolution of retinoic acid receptors and retinoic acid signaling. Subcell Biochem 2014; 70:55-73. [PMID: 24962881 DOI: 10.1007/978-94-017-9050-5_4] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Retinoic acid (RA) is a vitamin A-derived morphogen controlling important developmental processes in vertebrates, and more generally in chordates, including axial patterning and tissue formation and differentiation. In the embryo, endogenous RA levels are controlled by RA synthesizing and degrading enzymes and the RA signal is transduced by two retinoid receptors: the retinoic acid receptor (RAR) and the retinoid X receptor (RXR). Both RAR and RXR are members of the nuclear receptor superfamily of ligand-activated transcription factors and mainly act as heterodimers to activate the transcription of target genes in the presence of their ligand, all-trans RA. This signaling pathway was long thought to be a chordate innovation, however, recent findings of gene homologs involved in RA signaling in the genomes of a wide variety of non-chordate animals, including ambulacrarians (sea urchins and acorn worms) and lophotrochozoans (annelids and mollusks), challenged this traditional view and suggested that the RA signaling pathway might have a more ancient evolutionary origin than previously thought. In this chapter, we discuss the evolutionary history of the RA signaling pathway, and more particularly of the RARs, which might have experienced independent gene losses and duplications in different animal lineages. In sum, the available data reveal novel insights into the origin of the RA signaling pathway as well as into the evolutionary history of the RARs.
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Affiliation(s)
- Juliana Gutierrez-Mazariegos
- Molecular Zoology Team, Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon 1, CNRS, INRA, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364, Lyon Cedex 07, France,
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Durica DS, Das S, Najar F, Roe B, Phillips B, Kappalli S, Anilkumar G. Alternative splicing in the fiddler crab cognate ecdysteroid receptor: variation in receptor isoform expression and DNA binding properties in response to hormone. Gen Comp Endocrinol 2014; 206:80-95. [PMID: 25025945 DOI: 10.1016/j.ygcen.2014.05.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 04/19/2014] [Accepted: 05/16/2014] [Indexed: 01/07/2023]
Abstract
RXR cDNA cloning from three Uca species led to the identification of 4 conserved isoforms, indicative of alternative splicing in the hinge and ligand binding domains (LBD). Sequencing of overlapping clones from a Ucapugilator genomic library identified EcR isoforms matching previously identified cDNA variants; in addition, a cryptic exon in the LBD was detected and evidence for expression of this new isoform was obtained from next-generation sequencing. RNA-seq analysis also identified a new amino terminal EcR variant. EcR and RXR transcript abundance increases throughout ovarian maturation in U. pugilator, while cognate receptor transcript abundance remains constant in a related Indo-Pacific species with a different reproductive strategy. To examine if crab RXR LBD isoforms have different physical properties in vitro, electromobility shift assays were performed with different EcR isoforms. The cognate crab and fruit fly receptors differ in their responses to hormone. Ecdysteroids did not increase DNA binding for the crab heterodimers, while ecdysteroids stimulate binding for Drosophilamelanogaster EcR/USP heterodimers. In swapping experiments, UpEcR/USP heterodimers did not show ligand-responsive differences in DNA binding; both crab RXR LBD isoforms, however, conferred ligand-responsive increases in DNA binding with DmEcRs. These data indicate that both UpRXR LBD isoforms can heterodimerize with the heterologous DmEcR receptors and promote ligand and DNA binding. Unresponsiveness of the cognate receptors to ecdysteroid, however, suggest additional factors may be required to mediate endogenous, perhaps isoform-specific, differences in EcR conformation, consistent with previously reported effects of UpRXR isoforms on UpEcR ligand-binding affinities.
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Affiliation(s)
- David S Durica
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA.
| | - Sunetra Das
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Fares Najar
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA
| | - Bruce Roe
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA
| | - Barret Phillips
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | | | - Gopinathan Anilkumar
- School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore 632 014, India
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Rothwell CM, Spencer GE. Retinoid signaling is necessary for, and promotes long-term memory formation following operant conditioning. Neurobiol Learn Mem 2014; 114:127-40. [PMID: 24925874 DOI: 10.1016/j.nlm.2014.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 05/13/2014] [Accepted: 05/16/2014] [Indexed: 10/25/2022]
Abstract
Retinoic acid, a metabolite of vitamin A, is proposed to play an important role in vertebrate learning and memory, as well as hippocampal-dependent synaptic plasticity. However, it has not yet been determined whether retinoic acid plays a similar role in learning and memory in invertebrates. In this study, we report that retinoid signaling in the mollusc Lymnaea stagnalis, is required for long-term memory formation following operant conditioning of its aerial respiratory behaviour. Animals were exposed to inhibitors of the RALDH enzyme (which synthesizes retinoic acid), or various retinoid receptor antagonists. Following exposure to these inhibitors, neither learning nor intermediate-term memory (lasting 2 h) was affected, but long-term memory formation (tested at either 24 or 72 h) was inhibited. We next demonstrated that various retinoid receptor agonists promoted long-term memory formation. Using a training paradigm shown only to produce intermediate-term memory (lasting 2 h, but not 24 h) we found that exposure of animals to synthetic retinoids promoted memory formation that lasted up to 30 h. These findings suggest that the role of retinoids in memory formation is ancient in origin, and that retinoid signaling is also important for the formation of implicit memories, in addition to its previously demonstrated role in hippocampal-dependent memories.
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Affiliation(s)
- Cailin M Rothwell
- Department of Biological Sciences, Brock University, 500 Glenridge Ave, St. Catharines, ON L2S 3A1, Canada
| | - Gaynor E Spencer
- Department of Biological Sciences, Brock University, 500 Glenridge Ave, St. Catharines, ON L2S 3A1, Canada.
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Blum N, Begemann G. The roles of endogenous retinoid signaling in organ and appendage regeneration. Cell Mol Life Sci 2013; 70:3907-27. [PMID: 23479131 PMCID: PMC11113817 DOI: 10.1007/s00018-013-1303-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/29/2013] [Accepted: 02/14/2013] [Indexed: 12/20/2022]
Abstract
The ability to regenerate injured or lost body parts has been an age-old ambition of medical science. In contrast to humans, teleost fish and urodele amphibians can regrow almost any part of the body with seeming effortlessness. Retinoic acid is a molecule that has long been associated with these impressive regenerative capacities. The discovery 30 years ago that addition of retinoic acid to regenerating amphibian limbs causes "super-regeneration" initiated investigations into the presumptive roles of retinoic acid in regeneration of appendages and other organs. However, the evidence favoring or dismissing a role for endogenous retinoids in regeneration processes remained sparse and ambiguous. Now, the availability of genetic tools to manipulate and visualize the retinoic acid signaling pathway has opened up new routes to dissect its roles in regeneration. Here, we review the current understanding on endogenous functions of retinoic acid in regeneration and discuss key questions to be addressed in future research.
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Affiliation(s)
- Nicola Blum
- Developmental Biology, University of Bayreuth, 95440 Bayreuth, Germany
| | - Gerrit Begemann
- Developmental Biology, University of Bayreuth, 95440 Bayreuth, Germany
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Sainath S, Swetha CH, Reddy PS. What Do We (Need to) Know About the Melatonin in Crustaceans? ACTA ACUST UNITED AC 2013; 319:365-77. [DOI: 10.1002/jez.1800] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 03/25/2013] [Accepted: 04/01/2013] [Indexed: 11/06/2022]
Affiliation(s)
- S.B. Sainath
- Department of Biotechnology; Sri Venkateswara University; Tirupati, Andhra Pradesh; India
| | - CH. Swetha
- Department of Biotechnology; Sri Venkateswara University; Tirupati, Andhra Pradesh; India
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Das S, Durica DS. Ecdysteroid receptor signaling disruption obstructs blastemal cell proliferation during limb regeneration in the fiddler crab, Uca pugilator. Mol Cell Endocrinol 2013; 365:249-59. [PMID: 23142248 DOI: 10.1016/j.mce.2012.10.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/22/2012] [Accepted: 10/26/2012] [Indexed: 12/31/2022]
Abstract
To study ecdysteroid signaling during limb regeneration, we have applied RNAi (dsRNA) mediated silencing to EcR/RXR, the genes encoding the ecdysteroid receptor heterodimer, in the fiddler crab Uca pugilator. We injected RNAi into the blastemal chamber during early limb regeneration. Silencing was evaluated by knockdown in receptor transcript abundance, and disruption was evaluated by changes in growth rate and morphology of limb regenerates. q-PCR results indicated a 50% drop in transcript abundance 48h post injection in both RNAi (dsEcR/dsRXR) injected ipsilateral and uninjected contralateral blastemas in experimental animals relative to controls. EcR/RXR transcript levels further decreased over time. Several phenotypes were associated with knockdown. The experimental blastema failed to develop; microscopic examination of the arrested blastema revealed an absence of the cuticular ingrowths characteristic of the beginnings of limb segmentation and cell proliferation assays revealed that the arrested blastema had few dividing cells. Ecdysteroid levels were also lowered in experimental animals; given the bilateral effects of RNAi on limb buds in experimental animals, these results suggest RNAi had a systemic effect. Although hormone titers in experimental animals rose to comparable control levels during the late proecdysial phase of limb regeneration, most experimental crabs failed to molt and died. The overall failure to molt indicates that RNAi receptor knockdown has long-term effects. The combined effects of receptor knockdown indicate that, although circulating ecdysteroid titers are normally low during basal limb bud growth, signaling via the ecdysteroid receptor pathway is necessary for establishment of blastemal cell proliferation and development in the regenerating limbs of U. pugilator.
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Affiliation(s)
- Sunetra Das
- Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA
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Nagaraju GPC, Rajitha B, Borst DW. Molecular cloning and sequence of retinoid X receptor in the green crab Carcinus maenas: a possible role in female reproduction. J Endocrinol 2011; 210:379-90. [PMID: 21730047 DOI: 10.1530/joe-11-0154] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Retinoid X receptor (RXR) belongs to an ancient superfamily of nuclear hormone receptors, and plays an important role in reproduction of vertebrates. However, the reproductive role of RXR has not been clarified in crustaceans. In this investigation, we first report the cloning of two alternative splice variants of RXR cDNA from green crab ovarian RNA. RXR mRNA levels were quantified in different vitellogenic stages of the crab hepatopancreas (HP) and ovary. The expression of RXR mRNA relative to the arginine kinase mRNA was significantly increased in the HP of vitellogenic crabs in a stage-dependent manner. The relative levels of RXR mRNA in the ovary were significantly lower in vitellogenic stage III crabs than in crabs in the other three stages. These data indicate that the HP and ovary of the crab are capable of expressing RXR, which may regulate, in part, vitellogenesis in the crab. We also examined the effects of methyl farnesoate (MF) and RXR-dsRNA treatments on vitellogenin and RXR gene expression. Vitellogenin and RXR mRNA levels in HP and ovarian fragments incubated in MF were significantly (P<0.001) higher than in control tissue fragments prepared from the same animal. Treatment of crabs with RXR-dsRNA significantly (P<0.001) reduced mRNA levels for RXR and for vitellogenin as well as MF levels in hemolymph. These results indicate that, MF and RXR form a complex (MF-RXR) directly and together stimulate ovarian development in these green crabs. This interaction of RXR, MF, and ovary development axis is a novel finding and is the first report to the best of our knowledge.
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Hopkins PM, Durica D, Washington T. RXR isoforms and endogenous retinoids in the fiddler crab, Uca pugilator. Comp Biochem Physiol A Mol Integr Physiol 2008; 151:602-14. [DOI: 10.1016/j.cbpa.2008.07.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 07/15/2008] [Accepted: 07/21/2008] [Indexed: 10/21/2022]
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Stueckle TA, Likens J, Foran CM. Limb regeneration and molting processes under chronic methoprene exposure in the mud fiddler crab, Uca pugnax. Comp Biochem Physiol C Toxicol Pharmacol 2008; 147:366-77. [PMID: 18280794 DOI: 10.1016/j.cbpc.2008.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 12/28/2007] [Accepted: 01/04/2008] [Indexed: 11/26/2022]
Abstract
Insect growth regulator application for wetland mosquito control remains controversial due to the potential for disruption of normal development and growth processes in non-target crustaceans and beneficial arthropods, e.g. Apis mellifera. Concerns include slow-release methoprene formulations and its environmental breakdown products which mimic an endogenous crustacean hormone and retinoids, respectively. Our primary objective was to evaluate the effect that a chronic methoprene exposure would have on male and female Uca pugnax limb regeneration and molting. After single limb autonomy, limb growth and molt stage were monitored every two days while eyestalk ablation was used to induce proecdysis. Dorsal carapace was collected 6 days post-molt to determine protein and chitin content. In post-molt crabs, methoprene-exposed individuals displayed lower percent gain in body weight. Male crabs lost more weight per body volume than females, took significantly longer to proceed through proecdysis than females exposed to 0.1 microg/L methoprene and exhibited significantly elevated frequency for abnormal limb formation at 1.0 microg/L while females displayed no such trend. Methoprene did not significantly alter extractable exoskeleton protein or chitin content. However, variable water-soluble protein expression increased with exposure at 1.0 microg/L (1 ppb) which contributed to overall variability in total protein content. Our findings suggest that adult male U. pugnax possess greater sensitivity to chronic methoprene exposure during limb regeneration and molting, potentially affecting their post-molt fitness. Furthermore, methoprene has the potential to impact post-molt biomass and exocuticle quality.
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Affiliation(s)
- Todd A Stueckle
- Biology Department, West Virginia University, Morgantown, WV 26506-6057, USA.
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Simões-Costa MS, Azambuja AP, Xavier-Neto J. The search for non-chordate retinoic acid signaling: lessons from chordates. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2008; 310:54-72. [PMID: 17109394 DOI: 10.1002/jez.b.21139] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Signaling by retinoic acid (RA) is an important pathway in the development and homeostasis of vertebrate and invertebrate chordates, with a critical role in mesoderm patterning. Classical studies on the distribution of nuclear receptors of animals suggested that the family of RA receptors (RARs/NR1B) was restricted to chordates, while the family of RA X receptors (RXR/NR2B) was distributed from cnidarians to chordates. However, the accumulation of data from genome projects and studies in non-model species is questioning this traditional view. Here we discuss the evidence for non-chordate RA signaling systems in the light of recent advances in our understanding of carotene (pro-Vitamin A) metabolism and of the identification of potential RARs and members of the NR1 family in echinoderms and lophotrochozoan trematodes, respectively. We conclude, as have others before (Bertrand et al., 2004. Mol Biol Evol 21(10):1923-1937), that signaling by RA is more likely an ancestral feature of bilaterians than a chordate innovation.
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Affiliation(s)
- Marcos S Simões-Costa
- Laboratório de Genética e Cardiologia Molecular InCor--HC.FMUSP São Paulo-SP, Brazil
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16
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Reddy PS, Sainath SB. Effect of retinoic acid on hemolymph glucose regulation in the fresh water edible crab Oziotelphusa senex senex. Gen Comp Endocrinol 2008; 155:496-502. [PMID: 17964575 DOI: 10.1016/j.ygcen.2007.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 09/16/2007] [Accepted: 09/18/2007] [Indexed: 11/16/2022]
Abstract
9-cis-Retinoic acid (9CRA) and all-trans-retinoic acid (ATRA) are known to be involved in the regulation of glucose homeostasis in vertebrates by inducing insulin release and expression of glucose reporter proteins. In view of the fact that 9CRA and ATRA are endogenous in crustaceans and a retinoic acid X-receptor exists in crabs, we investigated whether 9CRA and ATRA also plays a role in glucose homeostasis in freshwater crab, Oziotelphusa senex senex. Injection of 9CRA into intact crabs significantly increased the hemolymph glucose level in a dose-dependent manner. Such 9CRA-induced hyperglycemia was apparently mediated by the CHH since injection of 9CRA into eyestalk-ablated crabs did not result in hyperglycemia. In support of this, administration of 9CRA in to crabs resulted in reduced hyperglycemic activity of eyestalks and elevated titers of CHH in hemolymph. ATRA injection did not cause any changes in hemolymph glucose and CHH levels. The results provide the first evidence that 9-cis-retinoic acid, but not all-trans-retinoic acid, is involved in the regulation of glucose homeostasis and apparently mediated by the eyestalk hormone CHH.
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Affiliation(s)
- P Sreenivasula Reddy
- Department of Biotechnology, Sri Venkateswara University, Tirupati 517502, India.
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17
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Abstract
Crustaceans are major constituents to aquatic ecosystems that provide a variety of ecological and economic services. Individual crustacean species are adept at occupying diverse niches and their success, in part, stems from neuro-endocrine signaling cascades that regulate physiology in response to environmental and internal cues. Peptide hormones are major signal transducers in crustaceans. The crustacean hyperglycemic hormone family of peptides regulates various aspects of growth, reproduction, and metabolism. These peptides may function as the terminal hormone to regulate some physiological activities or may function as intermediates in a signaling cascade. Ecdysteroids and terpenoids are two major classes of terminal signaling molecules in these cascades. Hormones from these two classes function independently or in concert to regulate various processes. Ecdysteroid signaling is subject to toxicological disruption through disturbances in ecdysteroid synthesis or binding of toxicants to the ecdysteroid receptor. Methyl farnesoate is the major terpenoid hormone of crustaceans and also is susceptible to disruption by environmental chemicals. However, the methyl farnesoate signaling pathway is poorly understood and only limited mechanistic confirmation for disruption of this endocrine signaling pathway exists. Disruption of the ecdysteroid/terpenoid signaling pathways in crustaceans has been associated with aberrations in growth, metamorphosis, reproductive maturation, sex determination, and sex differentiation. Population studies have revealed disruptions in crustacean growth, molting, sexual development, and recruitment that are indicative of environmental endocrine disruption. However, environmental factors other that pollution (i.e., temperature, parasitism) also can elicit these effects and definitive causal relationships between endocrine disruption in field populations of crustaceans and chemical pollution is generally lacking.
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Affiliation(s)
- Gerald A LeBlanc
- Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695-7633, USA.
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18
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Effects of All-trans retinoic acid on germ cell development of embryos and larvae of the giant freshwater prawn, Macrobrachium rosenbergii. Biologia (Bratisl) 2006. [DOI: 10.2478/s11756-006-0099-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Söderhäll I, Tangprasittipap A, Liu H, Sritunyalucksana K, Prasertsan P, Jiravanichpaisal P, Söderhäll K. Characterization of a hemocyte intracellular fatty acid-binding protein from crayfish (Pacifastacus leniusculus) and shrimp (Penaeus monodon). FEBS J 2006; 273:2902-12. [PMID: 16734719 DOI: 10.1111/j.1742-4658.2006.05303.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Intracellular fatty acid-binding proteins (FABPs) are small members of the superfamily of lipid-binding proteins, which occur in invertebrates and vertebrates. Included in this superfamily are the cellular retinoic acid-binding proteins and retinol-binding proteins, which seem to be restricted to vertebrates. Here, we report the cDNA cloning and characterization of two FABPs from hemocytes of the freshwater crayfish Pacifastacus leniusculus and the shrimp Penaeus monodon. In both these proteins, the binding triad residues involved in interaction with ligand carboxylate groups are present. From the sequence and homology modeling, the proteins are probably FABPs and not retinoic acid-binding proteins. The crayfish transcript (plFABP) was detected at high level in hemocytes, hepatopancreas, intestine and ovary and at low level in hematopoietic tissue and testis. Its expression in hematopoietic cells varied depending on the state of the crayfish from which it was isolated. Expression was 10-15 times higher in cultures isolated from crayfish with red colored plasma, in which hemocyte synthesis was high, if retinoic acid was added to the culture medium. In normal colored crayfish, with normal levels of hemocytes, no increase in expression of p1FABP was detected. Two other putative plFABP ligands, stearic acid and oleic acid, did not have any effect on plFABP expression in hematopoietic cells. These results suggest that retinoic acid-dependent signaling may be present in crustaceans.
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Affiliation(s)
- Irene Söderhäll
- Department of Comparative Physiology, Evolutionary Biology Centre, Uppsala University, Sweden.
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20
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Abstract
Retinoic acid (RA) is required for the differentiation and morphogenesis of chordate-specific features, such as the antero-posterior regionalization of the dorsal hollow nerve cord and neural crest cells. RA receptors (RARs) have been reported exclusively in chordates, suggesting that the acquisition of the RAR gene was important for chordate evolution. A scenario is presented here for the establishment of an RAR-mediated developmental regulatory system during the course of chordate evolution. In the common chordate ancestor, RAR came to control the spatial expression pattern of Hox genes in the ectoderm and endoderm along the antero-posterior axis. In these germ layers, RA was required for the differentiation of epidermal sensory neurons and the morphogenesis of pharyngeal gill slits, respectively. As the diffuse epidermal nerve net in the chordate ancestor became centralized to form the dorsal nerve cord, the epidermal Hox expression pattern was carried into the central nervous system. Because the Hox code here came to specify neuronal identity along the antero-posterior axis, RA became inextricably linked to the antero-posterior patterning of the chordate central nervous system.
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Affiliation(s)
- Shigeki Fujiwara
- Department of Materials Science, Kochi University, Kochi 780-8520, Japan.
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21
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Zou E, Bonvillain R. Effects of 9-cis- and all-trans-retinoic acids on blood glucose homeostasis in the fiddler crab, Uca pugilator. Comp Biochem Physiol C Toxicol Pharmacol 2003; 136:199-204. [PMID: 14659453 DOI: 10.1016/j.cca.2003.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
9-cis-Retinoic acid (9CRA) and all-trans-retinoic acid (ATRA) are known to be involved in the regulation of glucose homeostasis in vertebrates by inducing insulin release and expression of glucose transporter proteins. In view of the fact that both 9CRA and ATRA are endogenous to the fiddler crab, Uca pugilator, that a retinoid X receptor exists in this fiddler crab and that activities of insulin-like and insulin-like growth factor-like peptides have been reported for crustaceans, we investigated whether 9CRA and ATRA also play a role in glucose homeostasis in U. pugilator. Neither 9CRA nor ATRA was found to produce hypoglycemic effects at a dose of 10 microg/g live mass. However, 9CRA, but not ATRA, induced hyperglycemia. Such 9CRA-induced hyperglycemia was apparently mediated by the eyestalk hormone CHH since injection of 9CRA into eyestalk-ablated crabs did not result in hyperglycemia. ATRA was found to have an inhibitory effect on the recovery of blood glucose concentration following ATRA administration. Discussion on the possible mechanisms for the actions of 9CRA and ATRA was presented.
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Affiliation(s)
- Enmin Zou
- Department of Biological Sciences, Nicholls State University, Highway 1, Thibodaux, LA 70310, USA.
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22
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Nagatomo KI, Ishibashi T, Satou Y, Satoh N, Fujiwara S. Retinoic acid affects gene expression and morphogenesis without upregulating the retinoic acid receptor in the ascidian Ciona intestinalis. Mech Dev 2003; 120:363-72. [PMID: 12591605 DOI: 10.1016/s0925-4773(02)00441-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Many chordate-specific morphological features develop depending on retinoic acid (RA). We isolated cDNA clones encoding a retinoic acid receptor (CiRAR) and a retinoid X receptor (CiRXR) in the ascidian Ciona intestinalis. CiRAR mRNA was detected in the anterior ectoderm and endoderm during gastrulation. The expression persists in the head endoderm and two discrete regions of the nerve cord in the tailbud embryo. CiRXR mRNA was ubiquitously expressed. RA affected closure of the neural tube and formation of the adhesive papillae. However, no obvious upregulation in CiRAR expression was observed. Expression of some, but not all, of the neural and papilla-specific genes was reduced in the RA-treated embryo. These results suggest limited roles of CiRAR in ascidian embryos.
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Affiliation(s)
- Kan-ichiro Nagatomo
- Department of Biology, Faculty of Science, Kochi University, Kochi 780-8520, Japan
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23
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Gu PL, Gunawardene YINS, Chow BCK, He JG, Chan SM. Characterization of a novel cellular retinoic acid/retinol binding protein from shrimp: expression of the recombinant protein for immunohistochemical detection and binding assay. Gene 2002; 288:77-84. [PMID: 12034496 DOI: 10.1016/s0378-1119(02)00430-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Members of the cellular retinoic acid (CRABP) and retinol binding (CRBP) proteins family are involved in the metabolic pathways of retinoic acid (RA) and retinal respectively. The objective of this study is to determine whether such proteins are present in crustaceans. We report here the cloning and isolation of a novel complementary DNA (cDNA) that showed characteristics of the CRABP/CRBP from the ovary and eyestalk of the shrimp. The cDNA is 0.9 Kb in size and the deduced shrimp protein is encoded for a protein of 14 kDa. Although it shows high amino acids sequence similarity to both the vertebrate and invertebrate CRABP, some conserved amino acids identified in other CRABPs were not found in MeCRABP. MeCRABP is expressed in the ovary, eyestalk, testis, epidermis and early larvae. The presence of MeCRABP in early larval stages suggests that the protein may be involved in the early larval development. Recombinant MeCRABP was produced and used to generate a polyclonal antibody. In the immunohistochemical detection study, anti-rCRABP antibody recognized the presence of CRABP in several cell types of the eyestalk as well as the smaller oocytes of the ovary. Although MeCRABP messenger RNA transcripts can be detected in the ovary throughout the ovarian maturation period, CRABP was detected only in the primary oocytes of the ovary. The results suggest that CRABP transcripts in the mature ovary are not translated and may be supplied to the oocyte as maternal messages. The binding property of the recombinant MeCRABP was also tested by a fluorometeric method. The result indicates that rMeCRABP binds to both RA and retinal with similar affinity. This study represents the first cloning and characterization of a cDNA that belongs to a member of retinoid/fatty acid binding protein family in crustaceans.
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Affiliation(s)
- Pei-Li Gu
- Department of Zoology, The University of Hong Kong, Pokfulam Road, Hong Kong
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24
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Durica DS, Wu X, Anilkumar G, Hopkins PM, Chung ACK. Characterization of crab EcR and RXR homologs and expression during limb regeneration and oocyte maturation. Mol Cell Endocrinol 2002; 189:59-76. [PMID: 12039065 DOI: 10.1016/s0303-7207(01)00740-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report here complete coding sequences for the Uca pugilator homologs of the ecdysteroid (UpEcR) and retinoid-X receptors (UpRXR). Library screenings recovered cDNA clones containing a unique amino terminal open-reading frame (A/B domain) for each gene, most similar to insect B1 EcR and USP1/RXR isoforms. Splicing variants in the UpRXR ligand-binding domain were also identified, in a region critical for folding of Drosophila and lepidopteran USP. UpEcR and UpRXR proteins were able to associate, and both are required for binding to an ecdysteroid HRE; these interactions were not hormone-dependent. Ribonuclease protection assays (RPA) were conducted using A/B domain and 'common' (C or E) domain probes on RNA isolated from various stages of regenerating limb buds and ovaries. For several of the limb bud and ovarian stages examined, the relative level of A/B domain sequence protected was significantly less than common domain suggesting alternative amino terminal isoforms other than those isolated through cloning. This is the first report of UpEcR and UpRXR transcription during ovarian maturation, implicating the ovary as a potential target for hormonal control in Crustacea.
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Affiliation(s)
- David S Durica
- Department of Zoology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA.
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25
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Hopkins PM. Limb Regeneration in the Fiddler Crab,Uca pugilator: Hormonal and Growth Factor Control. ACTA ACUST UNITED AC 2001. [DOI: 10.1093/icb/41.3.389] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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26
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27
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Riddiford LM, Cherbas P, Truman JW. Ecdysone receptors and their biological actions. VITAMINS AND HORMONES 2001; 60:1-73. [PMID: 11037621 DOI: 10.1016/s0083-6729(00)60016-x] [Citation(s) in RCA: 365] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Affiliation(s)
- L M Riddiford
- Department of Zoology, University of Washington, Seattle 98195-1800, USA
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28
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Abstract
A homolog of retinoid X receptors (RXR), named PmRXR, was cloned from the budding ascidian, Polyandrocarpa misakiensis. Gel-shift assays revealed that PmRXR and a previously identified P. misakiensis retinoic acid receptor (PmRAR) formed a complex to bind vertebrate-type retinoic acid response element (RARE). Transfection assays were carried out using a reporter gene containing a RARE upstream of lacZ. Two chimeric effector genes were constructed by placing PmRXR and PmRAR cDNA fragments (containing the DNA-binding, ligand-binding and ligand-dependent transactivation domains) downstream of the human RXR alpha and RAR alpha cDNA (covering the N-terminal coding region), respectively. Each chimeric cDNA was ligated to a notochord-specific enhancer. In case the embryos were transfected with all three transgenes and treated with retinoic acid (RA), the reporter gene was activated in the notochord cells. The result suggests that the PmRXR/PmRAR complex functions as an RA-dependent transcriptional activator. The PmRXR mRNA was detected in a mesenchymal cell type, called glomerulocyte, in the developing Polyandrocarpa bud. As this cell type has been shown to express PmRAR mRNA, it seems possible that the PmRXR/PmRAR complex mediates RA signaling in this cell type to induce the expression of genes involved in the morphogenesis of the developing bud.
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Affiliation(s)
- M Kamimura
- Laboratory of Molecular and Cellular Biotechnology Faculty of Science, Kochi University, Japan
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29
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Chung AC, Durica DS, Clifton SW, Roe BA, Hopkins PM. Cloning of crustacean ecdysteroid receptor and retinoid-X receptor gene homologs and elevation of retinoid-X receptor mRNA by retinoic acid. Mol Cell Endocrinol 1998; 139:209-27. [PMID: 9705089 DOI: 10.1016/s0303-7207(98)00056-2] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report the cloning and analysis of ecdysteroid receptor (bpEcR) and retinoid-X receptor (UpRXR) cDNA homologs from the fiddler crab Uca pugilator. The deduced amino acid sequence of this crustacean EcR most closely resembles the insect EcRs within the DNA binding and ligand binding domains (LBDs). For UpRXR, the DNA binding domain (DBD) shares greatest identity to the insect USPs. The ligand binding domain, however, is closer to vertebrate RXRs but may have a nonfunctional AF-2 domain. Probes derived from these clones were used to examine transcript levels in blastemas during early limb regeneration. Both UpEcR and UpRXR transcripts were detected in low amounts 1 day after limb loss, but increased during the next 4 days. Immersion of crabs in sea water containing all-trans retinoic acid increased the steady state concentrations of UpRXR transcript and altered the pattern of circulating ecdysteroids. These effects correlate with the disruptive effects of retinoic acid on blastemal differentiation observed in earlier studies.
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Affiliation(s)
- A C Chung
- Department of Zoology, University of Oklahoma, Norman 73019, USA
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30
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Durica DS, Hopkins PM. Expression of the genes encoding the ecdysteroid and retinoid receptors in regenerating limb tissues from the fiddler crab, Uca pugilator. Gene X 1996; 171:237-41. [PMID: 8666279 DOI: 10.1016/0378-1119(96)00047-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Using sequence information derived from the Drosophila melanogaster (Dm) ecdysteroid receptor (EcR)- and retinoid X receptor (RXR)-encoding gene homologs, we have isolated cDNA clones corresponding to the DNA-binding domains (DBD) for these two nuclear receptors from the fiddler crab, Uca pugilator (Up). Both genes appear to be represented in 1-2 copies in the Up genome, and unlike Dm, contain an intron within the DBD-encoding region. Sequence comparisons to the Dm EcR and RXR homologs indicate 76 and 82% nucleotide identity, respectively, corresponding to 6 and 4 single-amino acid substitutions which primarily cluster in the region of the molecule involved in dimerization. RT-PCR analysis indicates that both the EcR and RXR homologs are expressed during the initial stages of limb regeneration, temporally concomitant with early blastema formation and the secretion of a flexible sac cuticle at the site of limb loss.
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Affiliation(s)
- D S Durica
- Department of Zoology, University of Oklahoma, Norman 73019, USA.
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