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Ma X, Xu S, Zhou Y, Zhang Q, Yang H, Wan B, Yang Y, Miao Z, Xu X. Targeting Nr2e3 to Modulate Tet2 Expression: Therapeutic Potential for Depression Treatment. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2400726. [PMID: 38881534 DOI: 10.1002/advs.202400726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 06/01/2024] [Indexed: 06/18/2024]
Abstract
Epigenetic mechanisms such as DNA methylation and hydroxymethylation play a significant role in depression. This research has shown that Ten-eleven translocation 2 (Tet2) deficiency prompts depression-like behaviors, but Tet2's transcriptional regulation remains unclear. In the study, bioinformatics is used to identify nuclear receptor subfamily 2 group E member 3 (Nr2e3) as a potential Tet2 regulator. Nr2e3 is found to enhance Tet2's transcriptional activity by binding to its promoter region. Nr2e3 knockdown in mouse hippocampus leads to reduced Tet2 expression, depression-like behaviors, decreased hydroxymethylation of synaptic genes, and downregulation of synaptic proteins like postsynaptic density 95 KDa (PSD95) and N-methy-d-aspartate receptor 1 (NMDAR1). Fewer dendritic spines are also observed. Nr2e3 thus appears to play an antidepressant role under stress. In search of potential treatments, small molecule compounds to increase Nr2e3 expression are screened. Azacyclonal (AZA) is found to enhance the Nr2e3/Tet2 pathway and exhibited antidepressant effects in stressed mice, increasing PSD95 and NMDAR1 expression and dendritic spine density. This study illuminates Tet2's upstream regulatory mechanism, providing a new target for identifying early depression biomarkers and developing treatments.
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Affiliation(s)
- Xiaohua Ma
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, 215000, China
- Institute of Neuroscience, Soochow University, Suzhou, 215123, China
| | - Shiyao Xu
- Institute of Neuroscience, Soochow University, Suzhou, 215123, China
| | - Yaohui Zhou
- Institute of Neuroscience, Soochow University, Suzhou, 215123, China
| | - Qian Zhang
- Institute of Neuroscience, Soochow University, Suzhou, 215123, China
| | - Hao Yang
- Department of Fetology, the First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Bo Wan
- Institute of Neuroscience, Soochow University, Suzhou, 215123, China
| | - Yong Yang
- Department of Psychiatry, the Affiliated Guangji Hospital of Soochow University, Suzhou, Jiangsu, 215000, China
| | - Zhigang Miao
- Institute of Neuroscience, Soochow University, Suzhou, 215123, China
| | - Xingshun Xu
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, 215000, China
- Institute of Neuroscience, Soochow University, Suzhou, 215123, China
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Soochow University, Suzhou, Jiangsu, 215123, China
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Long GY, Yang XB, Wang Z, Zeng QH, Yang H, Jin DC. Wing expansion functional analysis of ion transport peptide gene in Sogatella furcifera (Horváth) (Hemiptera: Delphacidae). Comp Biochem Physiol B Biochem Mol Biol 2024; 271:110946. [PMID: 38266956 DOI: 10.1016/j.cbpb.2024.110946] [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: 06/13/2023] [Revised: 01/20/2024] [Accepted: 01/20/2024] [Indexed: 01/26/2024]
Abstract
Ion transport peptide (ITP), a superfamily of arthropod neuropeptides, serves a crucial role in regulating various physiological processes such as diuresis, ecdysis behavior, and wing expansion. However, the molecular characteristics, expression profile, and role of ITP in Sogatella furcifera are poorly understood. To elucidate the characteristics and biological function of ITP in S. furcifera, we employed reverse transcription-polymerase chain reaction (RT-PCR) and RNA interference (RNAi) methods. The identified SfITP gene encodes 117 amino acids. The expression of SfITP gradually increased followed the formation of 3-day-old of 5th instar nymph, peaking initially at 40 min after eclosion, and reaching another peak 24 h after eclosion, with particularly high expression levels in thorax and wing tissues. Notably, SfITP RNAi in 3rd instar nymphs of S. furcifera significantly inhibited the transcript levels of SfITP, resulting in 55% mortality and 78% wing deformity. These findings suggests that SfITP is involved in the regulation of wing expansion in S. furcifera, providing insights into the regulation of insect wing expansion and contributing to the molecular understanding of this process.
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Affiliation(s)
- Gui-Yun Long
- School of Chinese Ethnic Medicine, Guizhou Minzu University, Key Laboratory of Guizhou Ethnic Medicine Resource Development and Utilization in Guizhou Minzu University, State Ethnic Affairs Commission, Guiyang 550025, China; Institute of Entomology, Guizhou University, Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions and Scientific Observation and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Guiyang 550025, China
| | - Xi-Bin Yang
- Institute of Entomology, Guizhou University, Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions and Scientific Observation and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Guiyang 550025, China; Plant Protection and Quarantine Station, Department of Agriculture and Rural Affairs of Guizhou Province, Guiyang 550001, People's Republic of China
| | - Zhao Wang
- College of Environment and Life Sciences, Kaili University, Kaili 556011, China
| | - Qing-Hui Zeng
- Institute of Entomology, Guizhou University, Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions and Scientific Observation and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Guiyang 550025, China
| | - Hong Yang
- Institute of Entomology, Guizhou University, Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions and Scientific Observation and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Guiyang 550025, China.
| | - Dao-Chao Jin
- Institute of Entomology, Guizhou University, Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions and Scientific Observation and Experimental Station of Crop Pests in Guiyang, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Guiyang 550025, China.
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Yang PJ, Chen EH, Song ZH, He W, Liu SH, Dou W, Wang JJ. Molecular Characterization and Expression Profiling of Nuclear Receptor Gene Families in Oriental Fruit Fly, Bactrocera Dorsalis (Hendel). INSECTS 2020; 11:E126. [PMID: 32079114 PMCID: PMC7074177 DOI: 10.3390/insects11020126] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 12/11/2022]
Abstract
The oriental fruit fly (Bactrocera dorsalis) is a pest that causes large economic losses in the fruit and vegetable industry, so its control is a major challenge. Nuclear receptors (NRs) are a superfamily of ligand-dependent transcription factors that directly combine with DNA to regulate the expression of downstream target genes. NRs are closely associated with multiple physiological processes such as metabolism, reproduction, and development. Through sequence searches and analysis, we identified 21 B. dorsalis NR genes, all of which contained at least one of the two characteristic binding domains. On the basis of the conserved sequences and phylogenetic relationships, we divided the 21 NR genes into seven subfamilies. All members of the NR0 subfamily and BdHR83, which belonged to the NR2E group, lacked ligand-binding domains. The BdDSF and BdHR51, which also belonged to the NR2Egroup, and BdE78 (which belonged to the NR1E group) all lacked DNA-binding domains. The BdDSF and BdHR83 sequences were incomplete, and were not successfully amplified. Development- and tissue-specific expression profiling demonstrated that the transcript levels of the 19 NR genes varied considerably among eggs, larva, pupae, and adults, as well as among larval and adult male and female tissues. Our results will contribute to a better understanding of NR evolution and expand our knowledge of B. dorsalis physiology.
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Affiliation(s)
- Pei-Jin Yang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Er-Hu Chen
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Zhong-Hao Song
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Wang He
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Shi-Huo Liu
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Wei Dou
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Jin-Jun Wang
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
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A Screening of UNF Targets Identifies Rnb, a Novel Regulator of Drosophila Circadian Rhythms. J Neurosci 2017; 37:6673-6685. [PMID: 28592698 DOI: 10.1523/jneurosci.3286-16.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 05/12/2017] [Accepted: 05/13/2017] [Indexed: 11/21/2022] Open
Abstract
Behavioral circadian rhythms are controlled by multioscillator networks comprising functionally different subgroups of clock neurons. Studies have demonstrated that molecular clocks in the fruit fly Drosophila melanogaster are regulated differently in clock neuron subclasses to support their specific functions (Lee et al., 2016; Top et al., 2016). The nuclear receptor unfulfilled (unf) represents a regulatory node that provides the small ventral lateral neurons (s-LNvs) unique characteristics as the master pacemaker (Beuchle et al., 2012). We previously showed that UNF interacts with the s-LNv molecular clocks by regulating transcription of the core clock gene period (per) (Jaumouillé et al., 2015). To gain more insight into the mechanisms by which UNF contributes to the functioning of the circadian master pacemaker, we identified UNF target genes using chromatin immunoprecipitation. Our data demonstrate that a previously uncharacterized gene CG7837, which we termed R and B (Rnb), acts downstream of UNF to regulate the function of the s-LNvs as the master circadian pacemaker. Mutations and LNv-targeted adult-restricted knockdown of Rnb impair locomotor rhythms. RNB localizes to the nucleus, and its loss-of-function blunts the molecular rhythms and output rhythms of the s-LNvs, particularly the circadian rhythms in PDF accumulation and axonal arbor remodeling. These results establish a second pathway by which UNF interacts with the molecular clocks in the s-LNvs and highlight the mechanistic differences in the molecular clockwork within the pacemaker circuit.SIGNIFICANCE STATEMENT Circadian behavior is generated by a pacemaker circuit comprising diverse classes of pacemaker neurons, each of which contains a molecular clock. In addition to the anatomical and functional diversity, recent studies have shown the mechanistic differences in the molecular clockwork among the pacemaker neurons in Drosophila Here, we identified the molecular characteristics distinguishing the s-LNvs, the master pacemaker of the locomotor rhythms, from other clock neuron subtypes. We demonstrated that a newly identified gene Rnb is an s-LNv-specific regulator of the molecular clock and essential for the generation of circadian locomotor behavior. Our results provide additional evidence to the emerging view that the differential regulation of the molecular clocks underlies the functional differences among the pacemaker neuron subgroups.
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The Function and Evolution of Nuclear Receptors in Insect Embryonic Development. Curr Top Dev Biol 2017; 125:39-70. [DOI: 10.1016/bs.ctdb.2017.01.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Bodofsky S, Koitz F, Wightman B. CONSERVED AND EXAPTED FUNCTIONS OF NUCLEAR RECEPTORS IN ANIMAL DEVELOPMENT. NUCLEAR RECEPTOR RESEARCH 2017; 4:101305. [PMID: 29333434 PMCID: PMC5761748 DOI: 10.11131/2017/101305] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The nuclear receptor gene family includes 18 members that are broadly conserved among multiple disparate animal phyla, indicating that they trace their evolutionary origins to the time at which animal life arose. Typical nuclear receptors contain two major domains: a DNA-binding domain and a C-terminal domain that may bind a lipophilic hormone. Many of these nuclear receptors play varied roles in animal development, including coordination of life cycle events and cellular differentiation. The well-studied genetic model systems of Drosophila, C. elegans, and mouse permit an evaluation of the extent to which nuclear receptor function in development is conserved or exapted (repurposed) over animal evolution. While there are some specific examples of conserved functions and pathways, there are many clear examples of exaptation. Overall, the evolutionary theme of exaptation appears to be favored over strict functional conservation. Despite strong conservation of DNA-binding domain sequences and activity, the nuclear receptors prove to be highly-flexible regulators of animal development.
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Affiliation(s)
- Shari Bodofsky
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Francine Koitz
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Bruce Wightman
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
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Yaniv SP, Schuldiner O. A fly's view of neuronal remodeling. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:618-35. [PMID: 27351747 PMCID: PMC5086085 DOI: 10.1002/wdev.241] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 04/10/2016] [Accepted: 04/18/2016] [Indexed: 11/17/2022]
Abstract
Developmental neuronal remodeling is a crucial step in sculpting the final and mature brain connectivity in both vertebrates and invertebrates. Remodeling includes degenerative events, such as neurite pruning, that may be followed by regeneration to form novel connections during normal development. Drosophila provides an excellent model to study both steps of remodeling since its nervous system undergoes massive and stereotypic remodeling during metamorphosis. Although pruning has been widely studied, our knowledge of the molecular and cellular mechanisms is far from complete. Our understanding of the processes underlying regrowth is even more fragmentary. In this review, we discuss recent progress by focusing on three groups of neurons that undergo stereotypic pruning and regrowth during metamorphosis, the mushroom body γ neurons, the dendritic arborization neurons and the crustacean cardioactive peptide peptidergic neurons. By comparing and contrasting the mechanisms involved in remodeling of these three neuronal types, we highlight the common themes and differences as well as raise key questions for future investigation in the field. WIREs Dev Biol 2016, 5:618–635. doi: 10.1002/wdev.241 For further resources related to this article, please visit the WIREs website
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Affiliation(s)
- Shiri P Yaniv
- Dept of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Oren Schuldiner
- Dept of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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Bates KE, Molnar J, Robinow S. The unfulfilled gene and nervous system development in Drosophila. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:217-23. [PMID: 24953188 DOI: 10.1016/j.bbagrm.2014.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 06/07/2014] [Accepted: 06/10/2014] [Indexed: 11/29/2022]
Abstract
The unfulfilled gene of Drosophila encodes a member of the NR2E subfamily of nuclear receptors. Like related members of the NR2E subfamily, UNFULFILLED is anticipated to function as a dimer, binding to DNA response elements and regulating the expression of target genes. The UNFULFILLED protein may be regulated by ligand-binding and may also be post-transcriptionally modified by sumoylation and phosphorylation. unfulfilled mutants display a range of aberrant phenotypes, problems with eclosion and post-eclosion behaviors, compromised fertility, arrhythmicity, and a lack of all adult mushroom body lobes. The locus of the fertility problem has not been determined. The behavioral arrhythmicity is due to the unfulfilled-dependent disruption of gene expression in a set of pacemaker neurons. The eclosion and the mushroom body lobe phenotypes of unfulfilled mutants are the result of developmental problems associated with failures in axon pathfinding or re-extension. Interest in genes that act downstream of unfulfilled has resulted in the identification of a growing number of unfulfilled interacting loci, providing the first glimpse into the composition of unfulfilled-dependent gene networks. This article is part of a Special Issue entitled: Nuclear receptors in animal development.
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Affiliation(s)
- Karen E Bates
- Department of Biology, University of Hawaii, Honolulu, HI 96822, USA
| | - Janos Molnar
- Department of Biology, University of Hawaii, Honolulu, HI 96822, USA
| | - Steven Robinow
- Department of Biology, University of Hawaii, Honolulu, HI 96822, USA.
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unfulfilled interacting genes display branch-specific roles in the development of mushroom body axons in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2014; 4:693-706. [PMID: 24558265 PMCID: PMC4577660 DOI: 10.1534/g3.113.009829] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The mushroom body (MB) of Drosophila melanogaster is an organized collection of interneurons that is required for learning and memory. Each of the three subtypes of MB neurons, γ, α´/β´, and α/β, branch at some point during their development, providing an excellent model in which to study the genetic regulation of axon branching. Given the sequential birth order and the unique patterning of MB neurons, it is likely that specific gene cascades are required for the different guidance events that form the characteristic lobes of the MB. The nuclear receptor UNFULFILLED (UNF), a transcription factor, is required for the differentiation of all MB neurons. We have developed and used a classical genetic suppressor screen that takes advantage of the fact that ectopic expression of unf causes lethality to identify candidate genes that act downstream of UNF. We hypothesized that reducing the copy number of unf-interacting genes will suppress the unf-induced lethality. We have identified 19 candidate genes that when mutated suppress the unf-induced lethality. To test whether candidate genes impact MB development, we performed a secondary phenotypic screen in which the morphologies of the MBs in animals heterozygous for unf and a specific candidate gene were analyzed. Medial MB lobes were thin, missing, or misguided dorsally in five double heterozygote combinations (;unf/+;axin/+, unf/+;Fps85D/+, ;unf/+;Tsc1/+, ;unf/+;Rheb/+, ;unf/+;msn/+). Dorsal MB lobes were missing in ;unf/+;DopR2/+ or misprojecting beyond the termination point in ;unf/+;Sytβ double heterozygotes. These data suggest that unf and unf-interacting genes play specific roles in axon development in a branch-specific manner.
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Yaniv SP, Issman-Zecharya N, Oren-Suissa M, Podbilewicz B, Schuldiner O. Axon regrowth during development and regeneration following injury share molecular mechanisms. Curr Biol 2012; 22:1774-82. [PMID: 22921367 DOI: 10.1016/j.cub.2012.07.044] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 07/19/2012] [Accepted: 07/19/2012] [Indexed: 11/24/2022]
Abstract
BACKGROUND The molecular mechanisms that determine axonal growth potential are poorly understood. Intrinsic growth potential decreases with age, and thus one strategy to identify molecular pathways controlling intrinsic growth potential is by studying developing young neurons. The programmed and stereotypic remodeling of Drosophila mushroom body (MB) neurons during metamorphosis offers a unique opportunity to uncover such mechanisms. Despite emerging insights into MB γ-neuron axon pruning, nothing is known about the ensuing axon re-extension. RESULTS Using mosaic loss of function, we found that the nuclear receptor UNF (Nr2e3) is cell autonomously required for the re-extension of MB γ-axons following pruning, but not for the initial growth or guidance of any MB neuron type. We found that UNF promotes this process of developmental axon regrowth via the TOR pathway as well as a late axon guidance program via an unknown mechanism. We have thus uncovered a novel developmental program of axon regrowth that is cell autonomously regulated by the UNF nuclear receptor and the TOR pathway. CONCLUSIONS Our results suggest that UNF activates neuronal re-extension during development. Taken together, we show that axon growth during developmental remodeling is mechanistically distinct from initial axon outgrowth. Due to the involvement of the TOR pathway in axon regeneration following injury, our results also suggests that developmental regrowth shares common molecular mechanisms with regeneration following injury.
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Affiliation(s)
- Shiri P Yaniv
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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Weber KP, Alvaro CG, Baer GM, Reinert K, Cheng G, Clever S, Wightman B. Analysis of C. elegans NR2E nuclear receptors defines three conserved clades and ligand-independent functions. BMC Evol Biol 2012; 12:81. [PMID: 22690911 PMCID: PMC3517510 DOI: 10.1186/1471-2148-12-81] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 05/31/2012] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The nuclear receptors (NRs) are an important class of transcription factors that are conserved across animal phyla. Canonical NRs consist of a DNA-binding domain (DBD) and ligand-binding domain (LBD). While most animals have 20-40 NRs, nematodes of the genus Caenorhabditis have experienced a spectacular proliferation and divergence of NR genes. The LBDs of evolutionarily-conserved Caenorhabditis NRs have diverged sharply from their Drosophila and vertebrate orthologs, while the DBDs have been strongly conserved. The NR2E family of NRs play critical roles in development, especially in the nervous system. In this study, we explore the phylogenetics and function of the NR2E family of Caenorhabditis elegans, using an in vivo assay to test LBD function. RESULTS Phylogenetic analysis reveals that the NR2E family of NRs consists of three broadly-conserved clades of orthologous NRs. In C. elegans, these clades are defined by nhr-67, fax-1 and nhr-239. The vertebrate orthologs of nhr-67 and fax-1 are Tlx and PNR, respectively. While the nhr-239 clade includes orthologs in insects (Hr83), an echinoderm, and a hemichordate, the gene appears to have been lost from vertebrate lineages. The C. elegans and C. briggsae nhr-239 genes have an apparently-truncated and highly-diverged LBD region. An additional C. elegans NR2E gene, nhr-111, appears to be a recently-evolved paralog of fax-1; it is present in C. elegans, but not C. briggsae or other animals with completely-sequenced genomes. Analysis of the relatively unstudied nhr-111 and nhr-239 genes demonstrates that they are both expressed--nhr-111 very broadly and nhr-239 in a small subset of neurons. Analysis of the FAX-1 LBD in an in vivo assay revealed that it is not required for at least some developmental functions. CONCLUSIONS Our analysis supports three conserved clades of NR2E receptors, only two of which are represented in vertebrates, indicating three ancestral NR2E genes in the urbilateria. The lack of a requirement for a FAX-1 LBD suggests that the relatively high level of sequence divergence for Caenorhabditis LBDs reflects relaxed selection on the primary sequence as opposed to divergent positive selection. This observation is consistent with a model in which divergence of some Caenorhabditis LBDs is allowed, at least in part, by the absence of a ligand requirement.
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Affiliation(s)
| | | | - G Michael Baer
- Biology Department, Muhlenberg College, Allentown, PA, 18104, USA
| | - Kristy Reinert
- Biology Department, Muhlenberg College, Allentown, PA, 18104, USA
| | - Genevieve Cheng
- Biology Department, Muhlenberg College, Allentown, PA, 18104, USA
| | - Sheila Clever
- Biology Department, Muhlenberg College, Allentown, PA, 18104, USA
| | - Bruce Wightman
- Biology Department, Muhlenberg College, Allentown, PA, 18104, USA
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Beuchle D, Jaumouillé E, Nagoshi E. The nuclear receptor unfulfilled is required for free-running clocks in Drosophila pacemaker neurons. Curr Biol 2012; 22:1221-7. [PMID: 22658597 DOI: 10.1016/j.cub.2012.04.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 01/26/2012] [Accepted: 04/24/2012] [Indexed: 10/28/2022]
Abstract
An intricate neural circuit composed of multiple classes of clock neurons controls circadian locomotor rhythms in Drosophila. Evidence indicates that the small ventral lateral neurons (s-LNvs, M cells) are the dominant pacemaker neurons that synchronize the clocks throughout the circuit and drive free-running locomotor rhythms. Little is known, however, about the molecular underpinning of this unique function of the s-LNvs. Here, we show that the nuclear receptor gene unfulfilled (unf; DHR51) is required for the function of the s-LNvs. UNFULFILLED (UNF) is rhythmically expressed in the s-LNvs, and unf mutant flies are behaviorally arrhythmic. Knockdown of unf in developing LNvs irreversibly destroys the ability of adult s-LNvs to generate free-running rhythms, whereas depletion of UNF from adult LNvs dampens the rhythms of the s-LNvs only in constant darkness. These temporally controlled LNv-targeted unf knockdowns desynchronize circuit-wide molecular rhythms and disrupt behavioral rhythms. Therefore, UNF is a prerequisite for free-running clocks in the s-LNvs and for the function of the entire circadian circuit.
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Affiliation(s)
- Dirk Beuchle
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland
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Xu J, Tan A, Palli SR. The function of nuclear receptors in regulation of female reproduction and embryogenesis in the red flour beetle, Tribolium castaneum. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:1471-80. [PMID: 20416316 PMCID: PMC2918696 DOI: 10.1016/j.jinsphys.2010.04.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 04/05/2010] [Accepted: 04/06/2010] [Indexed: 05/09/2023]
Abstract
Nineteen canonical and two Knirps-like family nuclear receptors (NRs) were identified in the genome of Tribolium castaneum. The current study was conducted to determine the function of these NRs in regulation of female reproduction and embryogenesis. RNA interference (RNAi)-aided knock-down in the expression of genes coding for 21 NRs showed that seven NRs E75, hormone receptor 3 (HR3), ecdysone receptor (EcR), ultraspiracle (USP), seven-up (SVP), FTZ transcription factor 1 (FTZ-F1) and hormone receptor 4 (HR4) are required for successful vitellogenesis and oogenesis. Knocking down the expression of genes coding for these seven NRs affected egg production by reducing the levels of vitellogenin mRNAs as well as by affecting the oocyte maturation. Expression of seven additional NRs hormone receptor 96 (HR96), hormone receptor 51 (HR51), hormone receptor 38 (HR38), hormone receptor 39 (HR39), Tailless (Tll), Dissatisfaction (Dsf) and Knirps-like is required for successful embryogenesis. The knock-down in the expression of genes coding for three other NRs (E78, hepatocyte nuclear factor 4, HNF4 and Eagle) partially blocked embryogenesis. This study showed that at least 17 out of the 21 NRs identified in T. castaneum play key roles in female reproduction and embryogenesis.
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Bates KE, Sung CS, Robinow S. The unfulfilled gene is required for the development of mushroom body neuropil in Drosophila. Neural Dev 2010; 5:4. [PMID: 20122139 PMCID: PMC2829026 DOI: 10.1186/1749-8104-5-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 02/01/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mushroom bodies (MBs) of Drosophila are required for complex behaviors and consist of three types of neurons, gamma, alpha'/beta' and alpha/beta. Previously, roles for transcription factors in MB neuronal differentiation have only been described for a subset of MB neurons. We are investigating the roles of unfulfilled (unf; HR51, CG16801) in MB development. unf encodes a nuclear receptor that is orthologous to the nuclear receptors fasciculation of axons defective 1 (FAX-1) of the nematode and photoreceptor specific nuclear receptor (PNR) of mammals. Based on our previous observations that unf transcripts accumulate in MB neurons at all developmental stages and the presence of axon pathfinding defects in fax-1 mutants, we hypothesized that unf regulates MB axon growth and pathfinding. RESULTS We show that unf mutants exhibit a range of highly penetrant axon stalling phenotypes affecting all neurons of the larval and adult MBs. Phenotypic analysis of unfX1 mutants revealed that alpha'/beta' and alpha/beta neurons initially project axons but stall prior to the formation of medial or dorsal MB lobes. unfZ0001 mutants form medial lobes, although these axons fail to branch, which results in a failure to form the alpha or alpha' dorsal lobes. In either mutant background, gamma neurons fail to develop larval-specific dorsal projections. These mutant gamma neurons undergo normal pruning, but fail to re-extend axons medially during pupal development. unfRNAi animals displayed phenotypes similar to those seen in unfZ0001 mutants. Unique asymmetrical phenotypes were observed in unfX1/unfZ0001 compound heterozygotes. Expression of UAS-unf transgenes in MB neurons rescues the larval and adult unf mutant phenotypes. CONCLUSIONS These data support the hypothesis that unf plays a common role in the development of all types of MB neurons. Our data indicate that unf is necessary for MB axon extension and branching and that the formation of dorsal collaterals is more sensitive to the loss of unf function than medial projections. The asymmetrical phenotypes observed in compound heterozygotes support the hypothesis that the earliest MB axons may serve as pioneers for the later-born MB neurons, providing evidence for pioneer MB axon guidance in post-embryonic development.
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Affiliation(s)
- Karen E Bates
- Department of Zoology, University of Hawaii, Honolulu, HI 96822, USA
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Lin S, Huang Y, Lee T. Nuclear receptor unfulfilled regulates axonal guidance and cell identity of Drosophila mushroom body neurons. PLoS One 2009; 4:e8392. [PMID: 20027309 PMCID: PMC2793019 DOI: 10.1371/journal.pone.0008392] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 11/25/2009] [Indexed: 11/12/2022] Open
Abstract
Nuclear receptors (NRs) comprise a family of ligand-regulated transcription factors that control diverse critical biological processes including various aspects of brain development. Eighteen NR genes exist in the Drosophila genome. To explore their roles in brain development, we knocked down individual NRs through the development of the mushroom bodies (MBs) by targeted RNAi. Besides recapitulating the known MB phenotypes for three NRs, we found that unfulfilled (unf), an ortholog of human photoreceptor specific nuclear receptor (PNR), regulates axonal morphogenesis and neuronal subtype identity. The adult MBs develop through remodeling of γ neurons plus de-novo elaboration of both α′/β′ and α/β neurons. Notably, unf is largely dispensable for the initial elaboration of γ neurons, but plays an essential role in their re-extension of axons after pruning during early metamorphosis. The subsequently derived MB neuron types also require unf for extension of axons beyond the terminus of the pruned bundle. Tracing single axons revealed misrouting rather than simple truncation. Further, silencing unf in single-cell clones elicited misguidance of axons in otherwise unperturbed MBs. Such axon guidance defects may occur as MB neurons partially lose their subtype identity, as evidenced by suppression of various MB subtype markers in unf knockdown MBs. In sum, unf governs axonal morphogenesis of multiple MB neuron types, possibly through regulating neuronal subtype identity.
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Affiliation(s)
- Suewei Lin
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Abstract
The molting process in arthropods is regulated by steroid hormones acting via nuclear receptor proteins. The most common molting hormone is the ecdysteroid, 20-hydroxyecdysone. The receptors of 20-hydroxyecdysone have also been identified in many arthropod species, and the amino acid sequences determined. The functional molting hormone receptors consist of two members of the nuclear receptor superfamily, namely the ecdysone receptor and the ultraspiracle, although the ecdysone receptor may be functional, in some instances, without the ultraspiracle. Generally, the ecdysone receptor/ultraspiracle heterodimer binds to a number of ecdysone response elements, sequence motifs that reside in the promoter of various ecdysteroid-responsive genes. In the ensuing transcriptional induction, the ecdysone receptor/ultraspiracle complex binds to 20-hydroxyecdysone or to a cognate ligand that, in turn, leads to the release of a corepressor and the recruitment of coactivators. 3D structures of the ligand-binding domains of the ecdysone receptor and the ultraspiracle have been solved for a few insect species. Ecdysone agonists bind to ecdysone receptors specifically, and ligand-ecdysone receptor binding is enhanced in the presence of the ultraspiracle in insects. The basic mode of ecdysteroid receptor action is highly conserved, but substantial functional differences exist among the receptors of individual species. Even though the transcriptional effects are apparently similar for ecdysteroids and nonsteroidal compounds such as diacylhydrazines, the binding shapes are different between them. The compounds having the strongest binding affinity to receptors ordinarily have strong molting hormone activity. The ability of the ecdysone receptor/ultraspiracle complex to manifest the effects of small lipophilic agonists has led to their use as gene switches for medical and agricultural applications.
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Affiliation(s)
- Yoshiaki Nakagawa
- Division of Applied Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo-Ku, Kyoto 606-8502, Japan.
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