1
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Wu Y, Zhou J, Zhang J, Tang Z, Chen X, Huang L, Liu S, Chen H, Wang Y. Pertinence of glioma and single nucleotide polymorphism of TERT, CCDC26, CDKN2A/B and RTEL1 genes in glioma: a meta-analysis. Front Oncol 2023; 13:1180099. [PMID: 37746290 PMCID: PMC10512948 DOI: 10.3389/fonc.2023.1180099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 08/08/2023] [Indexed: 09/26/2023] Open
Abstract
Background Previous genetic-epidemiological studies considered TERT (rs2736100), CCDC26 (rs4295627), CDKN2A/B (rs4977756) and RTEL1 (rs6010620) gene polymorphisms as the risk factors specific to glioma. However, the data samples of previous genetic-epidemiological studies are modest to determine whether they have definite association with glioma. Method The study paid attention to systematically searching databases of PubMed, Embase, Web of Science (WoS), Scopus, Cochrane Library and Google Scholars. Meta-analysis under 5 genetic models, namely recessive model (RM), over-dominant model (O-DM), allele model (AM), co-dominant model (C-DM) and dominant model (DM) was conducted for generating odds ratios (ORs) and 95% confidence intervals (CIs). That was accompanied by subgroup analyses according to various racial groups. The software STATA 17.0 MP was implemented in the study. Result 21 articles were collected. According to data analysis results, in four genetic models (AM, RM, DM and C-DM) TERT gene rs2736100 polymorphism, CCDC26 gene rs4295627 polymorphism, CDKN2A/B gene rs4977756 polymorphism and RTEL1 gene rs6010620 polymorphisms increased the risk of glioma in Caucasians to different degrees. In Asian populations, the CCDC26 gene rs4295627 polymorphism and CDKN2A/B gene rs4977756 polymorphism did not exhibit a relevance to the risk of glioma. It is suggested to cautiously explain these results as the sample size is small. Conclusion The current meta-analysis suggested that the SNP of TERT (rs2736100), CCDC26 (rs4295627), CDKN2A/B (rs4977756) and RTEL1 (rs6010620) genes in glioma might increase risk of glioma, but there are ethnic differences. Further studies evaluating these polymorphisms and glioma risk are warranted.
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Affiliation(s)
- Yaqi Wu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Zhou
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jun Zhang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhijian Tang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xi Chen
- School of Health, Brooks College, Sunnyvale, CA, United States
- Department of Epidemiology and Statistics, School of Public Health, Medical College, Zhejiang University, Hangzhou, China
| | - Lulu Huang
- Medical Affairs, the Department of ICON Pharma Development Solutions (IPD), ICON Public Limited Company (ICON Plc), Beijing, China
| | - Shengwen Liu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong Chen
- Dediatric Department, School of Clinical Medicine for Women and Children, China Three Gorges University, Yichang Maternal and Child Health Hospital, Yichang, China
| | - Yu Wang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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2
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Chousal JN, Sohni A, Vitting-Seerup K, Cho K, Kim M, Tan K, Porse B, Wilkinson MF, Cook-Andersen H. Progression of the pluripotent epiblast depends upon the NMD factor UPF2. Development 2022; 149:dev200764. [PMID: 36255229 PMCID: PMC9687065 DOI: 10.1242/dev.200764] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 09/09/2022] [Indexed: 11/09/2022]
Abstract
Nonsense-mediated RNA decay (NMD) is a highly conserved RNA turnover pathway that degrades RNAs harboring in-frame stop codons in specific contexts. Loss of NMD factors leads to embryonic lethality in organisms spanning the phylogenetic scale, but the mechanism remains unknown. Here, we report that the core NMD factor, UPF2, is required for expansion of epiblast cells within the inner cell mass of mice in vivo. We identify NMD target mRNAs in mouse blastocysts - both canonical and alternatively processed mRNAs - including those encoding cell cycle arrest and apoptosis factors, raising the possibility that NMD is essential for embryonic cell proliferation and survival. In support, the inner cell mass of Upf2-null blastocysts rapidly regresses with outgrowth and is incompetent for embryonic stem cell derivation in vitro. In addition, we uncovered concordant temporal- and lineage-specific regulation of NMD factors and mRNA targets, indicative of a shift in NMD magnitude during peri-implantation development. Together, our results reveal developmental and molecular functions of the NMD pathway in the early embryo.
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Affiliation(s)
- Jennifer N. Chousal
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Abhishek Sohni
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kristoffer Vitting-Seerup
- The Bioinformatics Centre, Department of Biology and Biotech Research & Innovation Centre, University of Copenhagen, 2200 Copenhagen, Denmark
- Section for Bioinformatics, Health Technology, Technical University of Denmark (DTU), 2800 Kongens Lyngby, Denmark
| | - Kyucheol Cho
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Matthew Kim
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kun Tan
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Bo Porse
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, DK2200 Copenhagen, Denmark
- Biotech Research and Innovation Center (BRIC), University of Copenhagen, 2200 Copenhagen, Denmark
- Novo Nordisk Foundation Center for Stem Cell Biology, DanStem, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Miles F. Wilkinson
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heidi Cook-Andersen
- Department of Obstetrics, Gynecology and Reproductive Sciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
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3
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Tan K, Stupack DG, Wilkinson MF. Nonsense-mediated RNA decay: an emerging modulator of malignancy. Nat Rev Cancer 2022; 22:437-451. [PMID: 35624152 PMCID: PMC11009036 DOI: 10.1038/s41568-022-00481-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/19/2022] [Indexed: 12/11/2022]
Abstract
Nonsense-mediated RNA decay (NMD) is a highly conserved RNA turnover pathway that selectively degrades RNAs harbouring truncating mutations that prematurely terminate translation, including nonsense, frameshift and some splice-site mutations. Recent studies show that NMD shapes the mutational landscape of tumours by selecting for mutations that tend to downregulate the expression of tumour suppressor genes but not oncogenes. This suggests that NMD can benefit tumours, a notion further supported by the finding that mRNAs encoding immunogenic neoantigen peptides are typically targeted for decay by NMD. Together, this raises the possibility that NMD-inhibitory therapy could be of therapeutic benefit against many tumour types, including those with a high load of neoantigen-generating mutations. Complicating this scenario is the evidence that NMD can also be detrimental for many tumour types, and consequently tumours often have perturbed NMD. NMD may suppress tumour generation and progression by degrading subsets of specific normal mRNAs, including those encoding stress-response proteins, signalling factors and other proteins beneficial for tumours, as well as pro-tumour non-coding RNAs. Together, these findings suggest that NMD-modulatory therapy has the potential to provide widespread therapeutic benefit against diverse tumour types. However, whether NMD should be stimulated or repressed requires careful analysis of the tumour to be treated.
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Affiliation(s)
- Kun Tan
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Dwayne G Stupack
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA.
- UCSD Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA.
| | - Miles F Wilkinson
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA.
- Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA, USA.
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4
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Goetz AE, Wilkinson M. Stress and the nonsense-mediated RNA decay pathway. Cell Mol Life Sci 2017; 74:3509-3531. [PMID: 28503708 PMCID: PMC5683946 DOI: 10.1007/s00018-017-2537-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/04/2017] [Accepted: 05/05/2017] [Indexed: 01/09/2023]
Abstract
Cells respond to internal and external cellular stressors by activating stress-response pathways that re-establish homeostasis. If homeostasis is not achieved in a timely manner, stress pathways trigger programmed cell death (apoptosis) to preserve organism integrity. A highly conserved stress pathway is the unfolded protein response (UPR), which senses excessive amounts of unfolded proteins in the ER. While a physiologically beneficial pathway, the UPR requires tight regulation to provide a beneficial outcome and avoid deleterious consequences. Recent work has demonstrated that a conserved and highly selective RNA degradation pathway-nonsense-mediated RNA decay (NMD)-serves as a major regulator of the UPR pathway. NMD degrades mRNAs encoding UPR components to prevent UPR activation in response to innocuous ER stress. In response to strong ER stress, NMD is inhibited by the UPR to allow for a full-magnitude UPR response. Recent studies have indicated that NMD also has other stress-related functions, including promoting the timely termination of the UPR to avoid apoptosis; NMD also regulates responses to non-ER stressors, including hypoxia, amino-acid deprivation, and pathogen infection. NMD regulates stress responses in species across the phylogenetic scale, suggesting that it has conserved roles in shaping stress responses. Stress pathways are frequently constitutively activated or dysregulated in human disease, raising the possibility that "NMD therapy" may provide clinical benefit by downmodulating stress responses.
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Affiliation(s)
- Alexandra E Goetz
- Department of Reproductive Medicine, School of Medicine, University of California San Diego, 9500 Gilman Dr., La Jolla, 92093, USA
| | - Miles Wilkinson
- Department of Reproductive Medicine, School of Medicine, University of California San Diego, 9500 Gilman Dr., La Jolla, 92093, USA.
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5
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Li XY, Liu GC, Sheng WJ, Dong ZW, Chen L, Zhao RP, Wang W. Genome editing in the butterfly type-species Papilio machaon. INSECT SCIENCE 2017; 24:708-711. [PMID: 28150375 DOI: 10.1111/1744-7917.12421] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/28/2016] [Accepted: 11/03/2016] [Indexed: 06/06/2023]
Affiliation(s)
- Xue-Yan Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Gui-Chun Liu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Wen-Jing Sheng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhi-Wei Dong
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Lei Chen
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruo-Ping Zhao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Wen Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
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6
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Geyer A, Koltsaki I, Hessinger C, Renner S, Rogulja-Ortmann A. Impact of Ultrabithorax alternative splicing on Drosophila embryonic nervous system development. Mech Dev 2015; 138 Pt 2:177-189. [PMID: 26299253 DOI: 10.1016/j.mod.2015.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 08/13/2015] [Accepted: 08/17/2015] [Indexed: 11/17/2022]
Abstract
Hox genes control divergent segment identities along the anteroposterior body axis of bilateral animals by regulating a large number of processes in a cell context-specific manner. How Hox proteins achieve this functional diversity is a long-standing question in developmental biology. In this study we investigate the role of alternative splicing in functional specificity of the Drosophila Hox gene Ultrabithorax (Ubx). We focus specifically on the embryonic central nervous system (CNS) and provide a description of temporal expression patterns of three major Ubx isoforms during development of this tissue. These analyses imply distinct functions for individual isoforms in different stages of neural development. We also examine the set of Ubx isoforms expressed in two isoform-specific Ubx mutant strains and analyze for the first time the effects of splicing defects on regional neural stem cell (neuroblast) identity. Our findings support the notion of specific isoforms having different effects in providing individual neuroblasts with positional identity along the anteroposterior body axis, as well as being involved in regulation of progeny cell fate.
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Affiliation(s)
- Aenne Geyer
- Institute of Genetics, University of Mainz, Mainz, Germany
| | | | | | - Simone Renner
- Institute of Genetics, University of Mainz, Mainz, Germany
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7
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Casadio A, Longman D, Hug N, Delavaine L, Vallejos Baier R, Alonso CR, Cáceres JF. Identification and characterization of novel factors that act in the nonsense-mediated mRNA decay pathway in nematodes, flies and mammals. EMBO Rep 2014; 16:71-8. [PMID: 25452588 PMCID: PMC4304730 DOI: 10.15252/embr.201439183] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a surveillance mechanism that degrades mRNAs harboring premature termination codons (PTCs). We have conducted a genome-wide RNAi screen in Caenorhabditis elegans that resulted in the identification of five novel NMD genes that are conserved throughout evolution. Two of their human homologs, GNL2 (ngp-1) and SEC13 (npp-20), are also required for NMD in human cells. We also show that the C. elegans gene noah-2, which is present in Drosophila melanogaster but absent in humans, is an NMD factor in fruit flies. Altogether, these data identify novel NMD factors that are conserved throughout evolution, highlighting the complexity of the NMD pathway and suggesting that yet uncovered novel factors may act to regulate this process.
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Affiliation(s)
- Angela Casadio
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital University of Edinburgh, Edinburgh, UK
| | - Dasa Longman
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital University of Edinburgh, Edinburgh, UK
| | - Nele Hug
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital University of Edinburgh, Edinburgh, UK
| | - Laurent Delavaine
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital University of Edinburgh, Edinburgh, UK
| | | | | | - Javier F Cáceres
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital University of Edinburgh, Edinburgh, UK
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8
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Rogulja-Ortmann A, Picao-Osorio J, Villava C, Patraquim P, Lafuente E, Aspden J, Thomsen S, Technau GM, Alonso CR. The RNA-binding protein ELAV regulates Hox RNA processing, expression and function within the Drosophila nervous system. Development 2014; 141:2046-56. [PMID: 24803653 PMCID: PMC4132933 DOI: 10.1242/dev.101519] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The regulated head-to-tail expression of Hox genes provides a coordinate system for the activation of specific programmes of cell differentiation according to axial level. Recent work indicates that Hox expression can be regulated via RNA processing but the underlying mechanisms and biological significance of this form of regulation remain poorly understood. Here we explore these issues within the developing Drosophila central nervous system (CNS). We show that the pan-neural RNA-binding protein (RBP) ELAV (Hu antigen) regulates the RNA processing patterns of the Hox gene Ultrabithorax (Ubx) within the embryonic CNS. Using a combination of biochemical, genetic and imaging approaches we demonstrate that ELAV binds to discrete elements within Ubx RNAs and that its genetic removal reduces Ubx protein expression in the CNS leading to the respecification of cellular subroutines under Ubx control, thus defining for the first time a specific cellular role of ELAV within the developing CNS. Artificial provision of ELAV in glial cells (a cell type that lacks ELAV) promotes Ubx expression, suggesting that ELAV-dependent regulation might contribute to cell type-specific Hox expression patterns within the CNS. Finally, we note that expression of abdominal A and Abdominal B is reduced in elav mutant embryos, whereas other Hox genes (Antennapedia) are not affected. Based on these results and the evolutionary conservation of ELAV and Hox genes we propose that the modulation of Hox RNA processing by ELAV serves to adapt the morphogenesis of the CNS to axial level by regulating Hox expression and consequently activating local programmes of neural differentiation.
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9
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Vannier JB, Sarek G, Boulton SJ. RTEL1: functions of a disease-associated helicase. Trends Cell Biol 2014; 24:416-25. [PMID: 24582487 DOI: 10.1016/j.tcb.2014.01.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 01/25/2014] [Accepted: 01/27/2014] [Indexed: 11/29/2022]
Abstract
DNA secondary structures that arise during DNA replication, repair, and recombination (3R) must be processed correctly to prevent genetic instability. Regulator of telomere length 1 (RTEL1) is an essential DNA helicase that disassembles a variety of DNA secondary structures to facilitate 3R processes and to maintain telomere integrity. The past few years have witnessed the emergence of RTEL1 variants that confer increased susceptibility to high-grade glioma, astrocytomas, and glioblastomas. Mutations in RTEL1 have also been implicated in Hoyeraal-Hreidarsson syndrome, a severe form of the bone-marrow failure and cancer predisposition disorder, dyskeratosis congenita. We review these recent findings and highlight its crucial link between DNA secondary-structure metabolism and human disease.
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Affiliation(s)
- Jean-Baptiste Vannier
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - Grzegorz Sarek
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK
| | - Simon J Boulton
- DNA Damage Response Laboratory, London Research Institute, Cancer Research UK, Clare Hall, South Mimms, EN6 3LD, UK.
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10
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Mallo M, Alonso CR. The regulation of Hox gene expression during animal development. Development 2013; 140:3951-63. [PMID: 24046316 DOI: 10.1242/dev.068346] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hox genes encode a family of transcriptional regulators that elicit distinct developmental programmes along the head-to-tail axis of animals. The specific regional functions of individual Hox genes largely reflect their restricted expression patterns, the disruption of which can lead to developmental defects and disease. Here, we examine the spectrum of molecular mechanisms controlling Hox gene expression in model vertebrates and invertebrates and find that a diverse range of mechanisms, including nuclear dynamics, RNA processing, microRNA and translational regulation, all concur to control Hox gene outputs. We propose that this complex multi-tiered regulation might contribute to the robustness of Hox expression during development.
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Affiliation(s)
- Moisés Mallo
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
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11
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Huang L, Wilkinson MF. Regulation of nonsense-mediated mRNA decay. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 3:807-28. [PMID: 23027648 DOI: 10.1002/wrna.1137] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) is a highly conserved pathway that was originally identified as a RNA surveillance mechanism that degrades aberrant mRNAs harboring premature termination (nonsense) codons. Recently, it was discovered that NMD also regulates normal gene expression. Genome-wide studies showed that ablation of NMD alters the expression of ∼10% of transcripts in a wide variety of eukaryotes. In general, NMD specifically targets normal transcripts that harbor a stop codon in a premature context. The finding that NMD regulates normal gene expression raises the possibility that NMD itself is subject to regulation. Indeed, recent studies have shown that NMD efficiency varies in different cell types and tissues. NMD is also subject to developmental control in both higher and lower eukaryotic species. Molecular mechanisms have been defined-including those involving microRNAs and other RNA decay pathways-that regulate the magnitude of NMD in some developmental settings. This developmental regulation of NMD appears to have physiological roles, at least in some model systems. In addition to mechanisms that modulate the efficiency of NMD, mechanisms have recently been identified that serve the opposite purpose: to maintain the efficiency of NMD in the face of insults. This 'buffering' is achieved by feedback networks that serve to regulate the stability of NMD factors. The discovery of NMD homeostasis and NMD regulatory mechanisms has important implications for how NMD acts in biological processes and how its magnitude could potentially be manipulated for clinical benefit.
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Affiliation(s)
- Lulu Huang
- Department of Reproductive Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, USA
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12
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Huang L, Lou CH, Chan W, Shum EY, Shao A, Stone E, Karam R, Song HW, Wilkinson MF. RNA homeostasis governed by cell type-specific and branched feedback loops acting on NMD. Mol Cell 2011; 43:950-61. [PMID: 21925383 DOI: 10.1016/j.molcel.2011.06.031] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 03/28/2011] [Accepted: 06/22/2011] [Indexed: 11/17/2022]
Abstract
Nonsense-mediated mRNA decay (NMD) is a conserved RNA decay pathway that degrades aberrant mRNAs and directly regulates many normal mRNAs. This dual role for NMD raises the possibility that its magnitude is buffered to prevent the potentially catastrophic alterations in gene expression that would otherwise occur if NMD were perturbed by environmental or genetic insults. In support of this, here we report the existence of a negative feedback regulatory network that directly acts on seven NMD factors. Feedback regulation is conferred by different branches of the NMD pathway in a cell type-specific and developmentally regulated manner. We identify feedback-regulated NMD factors that are rate limiting for NMD and demonstrate that reversal of feedback regulation in response to NMD perturbation is crucial for maintaining NMD. Together, our results suggest the existence of an intricate feedback network that maintains both RNA surveillance and the homeostasis of normal gene expression in mammalian cells.
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Affiliation(s)
- Lulu Huang
- Department of Reproductive Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
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13
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Matkovich SJ, Van Booven DJ, Cappola TP, Dorn GW. Association of an intronic, but not any exonic, FRMD4B sequence variant and heart failure. Clin Transl Sci 2010; 3:134-9. [PMID: 20718813 DOI: 10.1111/j.1752-8062.2010.00220.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Common forms of heart failure (HF) exhibit familial clustering, but specific genetic risk factors have been challenging to identify. A recent single-nucleotide polymorphism (SNP) microarray study implicated a locus within an intron of FRMD4B in Caucasian HF. Here, we used next-generation resequencing of pooled DNA and individual Sequenom genotyping to test for associations between FRMD4B SNPs and ischemic and/or nonischemic cardiomyopathy in two independent populations. Exonic resequencing of Caucasians and African-Americans identified 32 FRMD4B SNPs, 13 of which had allele frequencies greater than 1%. None of these common FRMD4B SNPs were significantly associated with ischemic, nonischemic, or all-cause HF in either of the study populations. We individually genotyped the seminal intronic rs6787362 FRMD4B SNP in the primary study population and compared genotypes between HF cases and controls. The rs6787362 variant allele was more frequent in Caucasians with ischemic cardiomyopathy, and carriers (heterozygous or homozygous) of the variant allele had increased risk of HF (OR 1.437, CI 1.085-1.904; p= 0.0118). No such association was seen for African-American HF. These results confirm an association between the intronic rs6787362 FRMD4B SNP and ischemic cardiomyopathy in a European-derived population, but do not support the proposition that coding FRMD4B variants are susceptibility factors in common HF.
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Affiliation(s)
- Scot J Matkovich
- The Center for Pharmacogenomics, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
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14
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Hansen KD, Lareau LF, Blanchette M, Green RE, Meng Q, Rehwinkel J, Gallusser FL, Izaurralde E, Rio DC, Dudoit S, Brenner SE. Genome-wide identification of alternative splice forms down-regulated by nonsense-mediated mRNA decay in Drosophila. PLoS Genet 2009; 5:e1000525. [PMID: 19543372 PMCID: PMC2689934 DOI: 10.1371/journal.pgen.1000525] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 05/18/2009] [Indexed: 01/21/2023] Open
Abstract
Alternative mRNA splicing adds a layer of regulation to the expression of thousands of genes in Drosophila melanogaster. Not all alternative splicing results in functional protein; it can also yield mRNA isoforms with premature stop codons that are degraded by the nonsense-mediated mRNA decay (NMD) pathway. This coupling of alternative splicing and NMD provides a mechanism for gene regulation that is highly conserved in mammals. NMD is also active in Drosophila, but its effect on the repertoire of alternative splice forms has been unknown, as has the mechanism by which it recognizes targets. Here, we have employed a custom splicing-sensitive microarray to globally measure the effect of alternative mRNA processing and NMD on Drosophila gene expression. We have developed a new algorithm to infer the expression change of each mRNA isoform of a gene based on the microarray measurements. This method is of general utility for interpreting splicing-sensitive microarrays and high-throughput sequence data. Using this approach, we have identified a high-confidence set of 45 genes where NMD has a differential effect on distinct alternative isoforms, including numerous RNA–binding and ribosomal proteins. Coupled alternative splicing and NMD decrease expression of these genes, which may in turn have a downstream effect on expression of other genes. The NMD–affected genes are enriched for roles in translation and mitosis, perhaps underlying the previously observed role of NMD factors in cell cycle progression. Our results have general implications for understanding the NMD mechanism in fly. Most notably, we found that the NMD–target mRNAs had significantly longer 3′ untranslated regions (UTRs) than the nontarget isoforms of the same genes, supporting a role for 3′ UTR length in the recognition of NMD targets in fly. A gene can be processed into multiple mRNAs through alternative splicing. Alternative splicing increases the number of proteins encoded by the genome, but not all alternative mRNAs produce protein. Instead, some are degraded by nonsense-mediated mRNA decay (NMD), a surveillance system that was originally identified as a means of clearing the cell of mRNAs with nonsense, or stop codon, mutations. Alternative splicing that introduces early stop codons will lead to NMD, offering a way for the cell to down-regulate gene expression after a gene has been transcribed. In this paper, we have developed a new analysis method to study the combined effect of alternative splicing and degradation in the fruit fly Drosophila melanogaster using microarrays. We have found a stringently defined set of 45 genes that can be spliced either into an mRNA that encodes a protein or into an mRNA that is degraded by NMD, down-regulating the overall gene expression. The affected genes include a number that are central to the cell's regulatory processes, including translation, RNA splicing, and cell cycle progression. Our results also help shed light on how NMD determines whether a stop codon is premature, and thus whether to target an mRNA for degradation.
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Affiliation(s)
- Kasper Daniel Hansen
- Division of Biostatistics, School of Public Health, University of California Berkeley, Berkeley, California, United States of America
| | - Liana F. Lareau
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Marco Blanchette
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Richard E. Green
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
- Max-Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Qi Meng
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Jan Rehwinkel
- Max-Planck Institute for Developmental Biology, Tuebingen, Germany
| | - Fabian L. Gallusser
- Division of Biostatistics, School of Public Health, University of California Berkeley, Berkeley, California, United States of America
| | - Elisa Izaurralde
- Max-Planck Institute for Developmental Biology, Tuebingen, Germany
| | - Donald C. Rio
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Sandrine Dudoit
- Division of Biostatistics, School of Public Health, University of California Berkeley, Berkeley, California, United States of America
| | - Steven E. Brenner
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
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15
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Analysis of the sequence and phenotype of Drosophila Sex combs reduced alleles reveals potential functions of conserved protein motifs of the Sex combs reduced protein. Genetics 2009; 182:191-203. [PMID: 19293143 DOI: 10.1534/genetics.109.100438] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Drosophila Hox gene, Sex combs reduced (Scr), is required for patterning the larval and adult, labial and prothoracic segments. Fifteen Scr alleles were sequenced and the phenotypes analyzed in detail. Six null alleles were nonsense mutations (Scr(2), Scr(4), Scr(11), Scr(13), Scr(13A), and Scr(16)) and one was an intragenic deletion (Scr(17)). Five hypomorphic alleles were missense mutations (Scr(1), Scr(3), Scr(5), Scr(6), and Scr(8)) and one was a small protein deletion (Scr(15)). Protein sequence changes were found in four of the five highly conserved domains of SCR: the DYTQL motif (Scr(15)), YPWM motif (Scr(3)), Homeodomain (Scr(1)), and C-terminal domain (CTD) (Scr(6)), indicating importance for SCR function. Analysis of the pleiotropy of viable Scr alleles for the formation of pseudotracheae suggests that the DYTQL motif and the CTD mediate a genetic interaction with proboscipedia. One allele Scr(14), a missense allele in the conserved octapeptide, was an antimorphic allele that exhibited three interesting genetic properties. First, Scr(14)/Df had the same phenotype as Scr(+)/Df. Second, the ability of the Scr(14) allele to interact intragenetically with Scr alleles mapped to the first 82 amino acids of SCR, which contains the octapeptide motif. Third, Scr(6), which has two missense changes in the CTD, did not interact genetically with Scr(14).
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16
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Lugassy J, McGrath JA, Itin P, Shemer R, Verbov J, Murphy HR, Ishida-Yamamoto A, Digiovanna JJ, Bercovich D, Karin N, Vitenshtein A, Uitto J, Bergman R, Richard G, Sprecher E. KRT14 haploinsufficiency results in increased susceptibility of keratinocytes to TNF-alpha-induced apoptosis and causes Naegeli-Franceschetti-Jadassohn syndrome. J Invest Dermatol 2007; 128:1517-24. [PMID: 18049449 DOI: 10.1038/sj.jid.5701187] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Naegeli-Franceschetti-Jadassohn syndrome (NFJS) is a rare autosomal dominant disorder characterized by loss of dermatoglyphics, reticulate hyperpigmentation of the skin, palmoplantar keratoderma, abnormal sweating, and other developmental anomalies of the teeth, hair, and skin. We recently demonstrated that NFJS is caused by heterozygous nonsense or frameshift mutations in the E1/V1-encoding region of KRT14, but the mechanisms for their deleterious effects in NFJS remain elusive. In this study, we further expand the spectrum of NFJS-causing mutations and demonstrate that these mutations result in haploinsufficiency for keratin 14 (K14). As increased apoptotic activity was observed in the epidermal basal cell layer in NFJS patients and as previous data suggested that type I keratins may confer resistance to tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis in epithelial tissues, we assessed the effect of down-regulation of KRT14 expression on apoptotic activity in keratinocytes. Using a HaCaT cell-based assay, we found that decreased KRT14 expression is associated with increased susceptibility to TNF-alpha-induced apoptosis. This phenomenon was not observed when cells were cultured in the presence of doxycycline, a known negative regulator of TNF-alpha-dependant pro-apoptotic signaling. Collectively, our results indicate that NFJS results from haploinsufficiency for K14 and suggest that increased susceptibility of keratinocytes to pro-apoptotic signals may be involved in the pathogenesis of this ectodermal dysplasia syndrome.
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Affiliation(s)
- Jennie Lugassy
- Laboratory of Molecular Dermatology and Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
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17
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Metzstein MM, Krasnow MA. Functions of the nonsense-mediated mRNA decay pathway in Drosophila development. PLoS Genet 2006; 2:e180. [PMID: 17196039 PMCID: PMC1756896 DOI: 10.1371/journal.pgen.0020180] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Accepted: 09/06/2006] [Indexed: 11/18/2022] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a cellular surveillance mechanism that degrades transcripts containing premature translation termination codons, and it also influences expression of certain wild-type transcripts. Although the biochemical mechanisms of NMD have been studied intensively, its developmental functions and importance are less clear. Here, we describe the isolation and characterization of Drosophila “photoshop” mutations, which increase expression of green fluorescent protein and other transgenes. Mapping and molecular analyses show that photoshop mutations are loss-of-function mutations in the Drosophila homologs of NMD genes Upf1, Upf2, and Smg1. We find that Upf1 and Upf2 are broadly active during development, and they are required for NMD as well as for proper expression of dozens of wild-type genes during development and for larval viability. Genetic mosaic analysis shows that Upf1 and Upf2 are required for growth and/or survival of imaginal cell clones, but this defect can be overcome if surrounding wild-type cells are eliminated. By contrast, we find that the PI3K-related kinase Smg1 potentiates but is not required for NMD or for viability, implying that the Upf1 phosphorylation cycle that is required for mammalian and Caenorhabditis elegans NMD has a more limited role during Drosophila development. Finally, we show that the SV40 3′ UTR, present in many Drosophila transgenes, targets the transgenes for regulation by the NMD pathway. The results establish that the Drosophila NMD pathway is broadly active and essential for development, and one critical function of the pathway is to endow proliferating imaginal cells with a competitive growth advantage that prevents them from being overtaken by other proliferating cells. Cells possess a variety of surveillance mechanisms that detect and dispose of defective gene products. One such system is the nonsense-mediated mRNA decay (NMD) pathway, which degrades aberrant mRNAs containing nonsense mutations or other premature translation stop signals. In a genetic screen in Drosophila, the authors identified a set of mutations they call “photoshop” mutations because they increase expression of green fluorescent protein transgenes such that cells expressing green fluorescent protein are more easily visualized. They found that the photoshop mutations are mutations in three different genes implicated in NMD. Using these mutations, they show that the NMD pathway not only degrades mutant mRNAs but also influences expression of many transgenes and dozens of endogenous genes during development and is essential for development beyond the larval stage. One important function of the pathway is to provide proliferating cells with a competitive growth advantage that prevents them from being overtaken by other proliferating cells during development. Thus, the Drosophila NMD pathway has critical cellular and developmental roles beyond the classical surveillance function of eliminating mutant transcripts.
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Affiliation(s)
- Mark M Metzstein
- Howard Hughes Medical Institute and Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
| | - Mark A Krasnow
- Howard Hughes Medical Institute and Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
- * To whom correspondence should be addressed. E-mail:
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18
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Alonso CR. Nonsense-mediated RNA decay: a molecular system micromanaging individual gene activities and suppressing genomic noise. Bioessays 2005; 27:463-6. [PMID: 15832387 DOI: 10.1002/bies.20227] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Nonsense-mediated RNA decay (NMD) is an evolutionary conserved system of RNA surveillance that detects and degrades RNA transcripts containing nonsense mutations. Given that these mutations arise at a relatively low frequency, are there any as yet unknown substrates of NMD in a wild-type cell? With this question in mind, Mendell et al. have used a microarray assay to identify those human genes under NMD regulation. Their results show that, in human cells, NMD regulates hundreds of physiologic transcripts and not just those containing nonsense mutations. Among the NMD targets are a number of non-functional RNAs expressed from vestigial sequences derived from retroviral and transposable elements. These findings support the notion that NMD is a high profile post-transcriptional mechanism micromanaging the activity of multiple gene batteries and suppressing the expression of genetic remnants.
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Affiliation(s)
- Claudio R Alonso
- Laboratory for Development and Evolution, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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19
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Negre B, Casillas S, Suzanne M, Sánchez-Herrero E, Akam M, Nefedov M, Barbadilla A, de Jong P, Ruiz A. Conservation of regulatory sequences and gene expression patterns in the disintegrating Drosophila Hox gene complex. Genome Res 2005; 15:692-700. [PMID: 15867430 PMCID: PMC1088297 DOI: 10.1101/gr.3468605] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Accepted: 01/26/2005] [Indexed: 11/25/2022]
Abstract
Homeotic (Hox) genes are usually clustered and arranged in the same order as they are expressed along the anteroposterior body axis of metazoans. The mechanistic explanation for this colinearity has been elusive, and it may well be that a single and universal cause does not exist. The Hox-gene complex (HOM-C) has been rearranged differently in several Drosophila species, producing a striking diversity of Hox gene organizations. We investigated the genomic and functional consequences of the two HOM-C splits present in Drosophila buzzatii. Firstly, we sequenced two regions of the D. buzzatii genome, one containing the genes labial and abdominal A, and another one including proboscipedia, and compared their organization with that of D. melanogaster and D. pseudoobscura in order to map precisely the two splits. Then, a plethora of conserved noncoding sequences, which are putative enhancers, were identified around the three Hox genes closer to the splits. The position and order of these enhancers are conserved, with minor exceptions, between the three Drosophila species. Finally, we analyzed the expression patterns of the same three genes in embryos and imaginal discs of four Drosophila species with different Hox-gene organizations. The results show that their expression patterns are conserved despite the HOM-C splits. We conclude that, in Drosophila, Hox-gene clustering is not an absolute requirement for proper function. Rather, the organization of Hox genes is modular, and their clustering seems the result of phylogenetic inertia more than functional necessity.
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Affiliation(s)
- Bárbara Negre
- Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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