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Blum JA, Wells M, Huxley-Reicher Z, Johnson JE, Bateman JR. Transvection between nonallelic genomic positions in Drosophila. G3 (Bethesda) 2024; 14:jkad255. [PMID: 37949840 PMCID: PMC10849331 DOI: 10.1093/g3journal/jkad255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
In Drosophila, pairing of maternal and paternal homologous chromosomes can permit trans-interactions between enhancers on one homolog and promoters on another, an example of transvection. Although trans-interactions have been observed at many loci in the Drosophila genome and in other organisms, the parameters that govern enhancer action in trans remain poorly understood. Using a transgenic reporter system, we asked whether enhancers and promoters at nonallelic, but nearby, genomic positions can communication in trans. Using one transgenic insertion carrying the synthetic enhancer GMR and another nearby insertion carrying the hsp70 promoter driving a fluorescent reporter, we show that transgenes separated by 2.6 kb of linear distance can support enhancer action in trans at the 53F8 locus. Furthermore, transvection between the nonallelic insertions can be augmented by a small deletion flanking one insert, likely via changes to the paired configuration of the homologs. Subsequent analyses of other insertions in 53F8 that carry different transgenic sequences demonstrate that the capacity to support transvection between nonallelic sites varies greatly, suggesting that factors beyond the linear distance between insertion sites play an important role. Finally, analysis of transvection between nearby nonallelic sites at other genomic locations shows evidence of position effects, where one locus supported GMR action in trans over a linear distance of over 10 kb, whereas another locus showed no evidence of transvection over a span <200 bp. Overall, our data demonstrate that transvection between nonallelic sites represents a complex interplay between genomic context, interallelic distance, and promoter identity.
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Affiliation(s)
- Jacob A Blum
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
| | - Michelle Wells
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
| | | | - Justine E Johnson
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
| | - Jack R Bateman
- Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, ME 04011, USA
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2
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Tav C, Fournier É, Fournier M, Khadangi F, Baguette A, Côté MC, Silveira MAD, Bérubé-Simard FA, Bourque G, Droit A, Bilodeau S. Glucocorticoid stimulation induces regionalized gene responses within topologically associating domains. Front Genet 2023; 14:1237092. [PMID: 37576549 PMCID: PMC10413275 DOI: 10.3389/fgene.2023.1237092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/07/2023] [Indexed: 08/15/2023] Open
Abstract
Transcription-factor binding to cis-regulatory regions regulates the gene expression program of a cell, but occupancy is often a poor predictor of the gene response. Here, we show that glucocorticoid stimulation led to the reorganization of transcriptional coregulators MED1 and BRD4 within topologically associating domains (TADs), resulting in active or repressive gene environments. Indeed, we observed a bias toward the activation or repression of a TAD when their activities were defined by the number of regions gaining and losing MED1 and BRD4 following dexamethasone (Dex) stimulation. Variations in Dex-responsive genes at the RNA levels were consistent with the redistribution of MED1 and BRD4 at the associated cis-regulatory regions. Interestingly, Dex-responsive genes without the differential recruitment of MED1 and BRD4 or binding by the glucocorticoid receptor were found within TADs, which gained or lost MED1 and BRD4, suggesting a role of the surrounding environment in gene regulation. However, the amplitude of the response of Dex-regulated genes was higher when the differential recruitment of the glucocorticoid receptor and transcriptional coregulators was observed, reaffirming the role of transcription factor-driven gene regulation and attributing a lesser role to the TAD environment. These results support a model where a signal-induced transcription factor induces a regionalized effect throughout the TAD, redefining the notion of direct and indirect effects of transcription factors on target genes.
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Affiliation(s)
- Christophe Tav
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Éric Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Michèle Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Fatemeh Khadangi
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Audrey Baguette
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
| | - Maxime C. Côté
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Maruhen A. D. Silveira
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Félix-Antoine Bérubé-Simard
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Guillaume Bourque
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
- Canadian Center for Computational Genomics, McGill University, Montréal, QC, Canada
| | - Arnaud Droit
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Centre de Recherche du CHU de Québec—Université Laval, Axe Endocrinologie et Néphrologie, Québec, QC, Canada
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Steve Bilodeau
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
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3
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Cittadino GM, Andrews J, Purewal H, Estanislao Acuña Avila P, Arnone JT. Functional Clustering of Metabolically Related Genes Is Conserved across Dikarya. J Fungi (Basel) 2023; 9:jof9050523. [PMID: 37233234 DOI: 10.3390/jof9050523] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/08/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023] Open
Abstract
Transcriptional regulation is vital for organismal survival, with many layers and mechanisms collaborating to balance gene expression. One layer of this regulation is genome organization, specifically the clustering of functionally related, co-expressed genes along the chromosomes. Spatial organization allows for position effects to stabilize RNA expression and balance transcription, which can be advantageous for a number of reasons, including reductions in stochastic influences between the gene products. The organization of co-regulated gene families into functional clusters occurs extensively in Ascomycota fungi. However, this is less characterized within the related Basidiomycota fungi despite the many uses and applications for the species within this clade. This review will provide insight into the prevalence, purpose, and significance of the clustering of functionally related genes across Dikarya, including foundational studies from Ascomycetes and the current state of our understanding throughout representative Basidiomycete species.
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Affiliation(s)
- Gina M Cittadino
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
| | - Johnathan Andrews
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
| | - Harpreet Purewal
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
| | | | - James T Arnone
- Department of Biological and Environmental Sciences, Le Moyne College, Syracuse, NY 13214, USA
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Nickels JF, Della-Rosa ME, Miguelez Goyeneche I, Charlton SJ, Sneppen K, Thon G. The transcription factor Atf1 lowers the transition barrier for nucleosome-mediated establishment of heterochromatin. Cell Rep 2022; 39:110828. [PMID: 35584672 DOI: 10.1016/j.celrep.2022.110828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/09/2022] [Accepted: 04/26/2022] [Indexed: 11/22/2022] Open
Abstract
Transcription factors can exert opposite effects depending on the chromosomal context. The fission yeast transcription factor Atf1 both activates numerous genes in response to stresses and mediates heterochromatic gene silencing in the mating-type region. Investigating this context dependency, we report here that the establishment of silent heterochromatin in the mating-type region occurs at a reduced rate in the absence of Atf1 binding. Quantitative modeling accounts for the observed establishment profiles by a combinatorial recruitment of histone-modifying enzymes: locally by Atf1 at two binding sites and over the whole region by dynamically appearing heterochromatic nucleosomes, a source of which is the RNAi-dependent cenH element. In the absence of Atf1 binding, the synergy is lost, resulting in a slow rate of heterochromatin formation. The system shows how DNA-binding proteins can influence local nucleosome states and thereby potentiate long-range positive feedback on histone-modification reactions to enable heterochromatin formation over large regions in a context-dependent manner.
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Damián A, Ionescu RO, Rodríguez de Alba M, Tamayo A, Trujillo-Tiebas MJ, Cotarelo-Pérez MC, Pérez Rodríguez O, Villaverde C, de la Fuente L, Romero R, Núñez-Moreno G, Mínguez P, Ayuso C, Cortón M. Fine Breakpoint Mapping by Genome Sequencing Reveals the First Large X Inversion Disrupting the NHS Gene in a Patient with Syndromic Cataracts. Int J Mol Sci 2021; 22:ijms222312713. [PMID: 34884523 PMCID: PMC8657747 DOI: 10.3390/ijms222312713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 11/16/2022] Open
Abstract
Inversions are structural variants that are generally balanced. However, they could lead to gene disruptions or have positional effects leading to diseases. Mutations in the NHS gene cause Nance-Horan syndrome, an X-linked disorder characterised by congenital cataracts and dental anomalies. Here, we aimed to characterise a balanced pericentric inversion X(p22q27), maternally inherited, in a child with syndromic bilateral cataracts by breakpoint mapping using whole-genome sequencing (WGS). 30× Illumina paired-end WGS was performed in the proband, and breakpoints were confirmed by Sanger sequencing. EdU assays and FISH analysis were used to assess skewed X-inactivation patterns. RNA expression of involved genes in the breakpoint boundaries was evaluated by droplet-digital PCR. We defined the breakpoint position of the inversion at Xp22.13, with a 15 bp deletion, disrupting the unusually large intron 1 of the canonical NHS isoform, and also perturbing topologically-associated domains (TADs). Moreover, a microhomology region of 5 bp was found on both sides. RNA analysis confirmed null and reduced NHS expression in the proband and his unaffected mother, respectively. In conclusion, we report the first chromosomal inversion disrupting NHS, fine-mapped by WGS. Our data expand the clinical spectrum and the pathogenic mechanisms underlying the NHS defects.
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Affiliation(s)
- Alejandra Damián
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
| | - Raluca Oancea Ionescu
- Department of Medical Genetics, University Hospital Clínico San Carlos, 28040 Madrid, Spain; (R.O.I.); (M.C.C.P.)
| | - Marta Rodríguez de Alba
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
| | - Alejandra Tamayo
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
| | - María José Trujillo-Tiebas
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
| | - María Carmen Cotarelo-Pérez
- Department of Medical Genetics, University Hospital Clínico San Carlos, 28040 Madrid, Spain; (R.O.I.); (M.C.C.P.)
| | - Olga Pérez Rodríguez
- Department of Pediatrics, University Hospital Clínico San Carlos, 28040 Madrid, Spain;
| | - Cristina Villaverde
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
| | - Lorena de la Fuente
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
| | - Raquel Romero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
| | - Gonzalo Núñez-Moreno
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
| | - Pablo Mínguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040, Madrid, Spain
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
| | - Marta Cortón
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain; (A.D.); (M.R.d.A.); (A.T.); (M.J.T.-T); (C.V.); (L.d.l.F.); (R.R.); (G.N.-M); (P.M.); (C.A.)
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), 28290 Madrid, Spain
- Correspondence:
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Socha M, Sowińska-Seidler A, Melo US, Kragesteen BK, Franke M, Heinrich V, Schöpflin R, Nagel I, Gruchy N, Mundlos S, Sreenivasan VK, López C, Vingron M, Bukowska-Olech E, Spielmann M, Jamsheer A. Position effects at the FGF8 locus are associated with femoral hypoplasia. Am J Hum Genet 2021; 108:1725-1734. [PMID: 34433009 DOI: 10.1016/j.ajhg.2021.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022] Open
Abstract
Copy-number variations (CNVs) are a common cause of congenital limb malformations and are interpreted primarily on the basis of their effect on gene dosage. However, recent studies show that CNVs also influence the 3D genome chromatin organization. The functional interpretation of whether a phenotype is the result of gene dosage or a regulatory position effect remains challenging. Here, we report on two unrelated families with individuals affected by bilateral hypoplasia of the femoral bones, both harboring de novo duplications on chromosome 10q24.32. The ∼0.5 Mb duplications include FGF8, a key regulator of limb development and several limb enhancer elements. To functionally characterize these variants, we analyzed the local chromatin architecture in the affected individuals' cells and re-engineered the duplications in mice by using CRISPR-Cas9 genome editing. We found that the duplications were associated with ectopic chromatin contacts and increased FGF8 expression. Transgenic mice carrying the heterozygous tandem duplication including Fgf8 exhibited proximal shortening of the limbs, resembling the human phenotype. To evaluate whether the phenotype was a result of gene dosage, we generated another transgenic mice line, carrying the duplication on one allele and a concurrent Fgf8 deletion on the other allele, as a control. Surprisingly, the same malformations were observed. Capture Hi-C experiments revealed ectopic interaction with the duplicated region and Fgf8, indicating a position effect. In summary, we show that duplications at the FGF8 locus are associated with femoral hypoplasia and that the phenotype is most likely the result of position effects altering FGF8 expression rather than gene dosage effects.
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Gui Q, Deng S, Zhou Z, Cao W, Zhang X, Shi W, Cai X, Jiang W, Cui Z, Hu Z, Chen X. Transcriptome Analysis in Yeast Reveals the Externality of Position Effects. Mol Biol Evol 2021; 38:3294-3307. [PMID: 33871622 PMCID: PMC8321525 DOI: 10.1093/molbev/msab104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The activity of a gene newly integrated into a chromosome depends on the genomic context of the integration site. This “position effect” has been widely reported, although the other side of the coin, that is, how integration affects the local chromosomal environment, has remained largely unexplored, as have the mechanism and phenotypic consequences of this “externality” of the position effect. Here, we examined the transcriptome profiles of approximately 250 Saccharomyces cerevisiae strains, each with GFP integrated into a different locus of the wild-type strain. We found that in genomic regions enriched in essential genes, GFP expression tended to be lower, and the genes near the integration site tended to show greater expression reduction. Further joint analysis with public genome-wide histone modification profiles indicated that this effect was associated with H3K4me2. More importantly, we found that changes in the expression of neighboring genes, but not GFP expression, significantly altered the cellular growth rate. As a result, genomic loci that showed high GFP expression immediately after integration were associated with growth disadvantages caused by elevated expression of neighboring genes, ultimately leading to a low total yield of GFP in the long run. Our results were consistent with competition for transcriptional resources among neighboring genes and revealed a previously unappreciated facet of position effects. This study highlights the impact of position effects on the fate of exogenous gene integration and has significant implications for biological engineering and the pathology of viral integration into the host genome.
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Affiliation(s)
- Qian Gui
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Shuyun Deng
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - ZhenZhen Zhou
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Waifang Cao
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Xin Zhang
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Wenjun Shi
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Xiujuan Cai
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Wenbing Jiang
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Zifeng Cui
- Department of Obstetrics and Gynecology, Precision Medicine Institute, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zheng Hu
- Department of Obstetrics and Gynecology, Precision Medicine Institute, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xiaoshu Chen
- Department of Biology and Medical Genetics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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8
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Nyman TJ, Antfolk J, Lampinen JM, Korkman J, Santtila P. Line-Up Image Position in Simultaneous and Sequential Line-Ups: The Effects of Age and Viewing Distance on Selection Patterns. Front Psychol 2020; 11:1349. [PMID: 32714240 PMCID: PMC7342269 DOI: 10.3389/fpsyg.2020.01349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 05/20/2020] [Indexed: 11/13/2022] Open
Abstract
It is known that children and older adults produce more false alarms in target absent line-ups and that weaker facial encoding increases choosing bias. However, there has been no investigation of how age or facial encoding strength impacts line-up position selections in either sequential or simultaneous line-ups. In the present study, we presented participants with four live targets (one by one) while manipulating sequential and simultaneous line-ups between participants and target present and target absent line-ups within participants. In order to investigate facial encoding strength, we presented the targets at distances between 5 and 110 m. Our main hypotheses were that children due to deficits with inhibition would be more biased toward indiscriminate selections in the first position of sequential line-ups compared with subsequent line-up positions and that first position selections would increase for all age groups as facial encoding became weaker. In simultaneous line-ups, we expected to find a top row bias. In our sample (N = 1,588 participants; 6–77 years), we found that younger children (6–11 years) and the oldest adults (60–77 years) showed a first position bias in sequential line-ups, and as facial encoding became weaker, all age groups (6–11, 12–17, 18–44, 45–59, and 60–77 years) showed an increased tendency to make first position selections. We also found a weak top row preference in simultaneous line-ups, which was moderated by age and increased distance. The main finding is that the results suggest that younger children and the oldest adults had a tendency toward a first position selection bias in sequential line-ups. Based on the combined results, we recommend caution when using sequential line-ups with younger children or older adults.
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Affiliation(s)
- Thomas J Nyman
- Faculty of Arts, Psychology and Theology, Åbo Akademi University, Turku, Finland.,Faculty of Arts and Sciences, New York University Shanghai, Shanghai, China
| | - Jan Antfolk
- Faculty of Arts, Psychology and Theology, Åbo Akademi University, Turku, Finland
| | - James Michael Lampinen
- Department of Psychological Science, University of Arkansas, Fayetteville, AR, United States
| | - Julia Korkman
- Faculty of Arts, Psychology and Theology, Åbo Akademi University, Turku, Finland
| | - Pekka Santtila
- Faculty of Arts and Sciences, New York University Shanghai, Shanghai, China
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9
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Arnone JT. Genomic Considerations for the Modification of Saccharomyces cerevisiae for Biofuel and Metabolite Biosynthesis. Microorganisms 2020; 8:E321. [PMID: 32110897 DOI: 10.3390/microorganisms8030321] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/02/2020] [Accepted: 02/24/2020] [Indexed: 11/22/2022] Open
Abstract
The growing global population and developing world has put a strain on non-renewable natural resources, such as fuels. The shift to renewable sources will, thus, help meet demands, often through the modification of existing biosynthetic pathways or the introduction of novel pathways into non-native species. There are several useful biosynthetic pathways endogenous to organisms that are not conducive for the scale-up necessary for industrial use. The use of genetic and synthetic biological approaches to engineer these pathways in non-native organisms can help ameliorate these challenges. The budding yeast Saccharomyces cerevisiae offers several advantages for genetic engineering for this purpose due to its widespread use as a model system studied by many researchers. The focus of this review is to present a primer on understanding genomic considerations prior to genetic modification and manipulation of S. cerevisiae. The choice of a site for genetic manipulation can have broad implications on transcription throughout a region and this review will present the current understanding of position effects on transcription.
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Abstract
Transvection is an epigenetic phenomenon wherein regulatory elements communicate between different chromosomes in trans, and is thereby dependent upon the three-dimensional organization of the genome. Transvection is best understood in Drosophila, where homologous chromosomes are closely paired in most somatic nuclei, although similar phenomena have been observed in other species. Previous data have supported that the Drosophila genome is generally permissive to enhancer action in trans, a form of transvection where an enhancer on one homolog activates gene expression from a promoter on a paired homolog. However, the capacity of different genomic positions to influence the quantitative output of transvection has yet to be addressed. To investigate this question, we employed a transgenic system that assesses and compares enhancer action in cis and in trans at defined chromosomal locations. Using the strong synthetic eye-specific enhancer GMR, we show that loci supporting strong cis-expression tend to support robust enhancer action in trans, whereas locations with weaker cis-expression show reduced transvection in a fluorescent reporter assay. Our subsequent analysis is consistent with a model wherein the chromatin state of the transgenic insertion site is a primary determinant of the degree to which enhancer action in trans will be supported, whereas other factors such as locus-specific variation in somatic homolog pairing are of less importance in influencing position effects on transvection.
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Affiliation(s)
- Thomas D King
- Biology Department, Bowdoin College, Brunswick, Maine 04011
| | | | - Jack R Bateman
- Biology Department, Bowdoin College, Brunswick, Maine 04011
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Chen W, Huang G, Li X, Li Y, Wang H, Jiang H, Zhao Z, Yu D, Wang E, Yang R. Revealing the Position Effect of an Alkylthio Side Chain in Phenyl-Substituted Benzodithiophene-Based Donor Polymers on the Photovoltaic Performance of Non-Fullerene Organic Solar Cells. ACS Appl Mater Interfaces 2019; 11:33173-33178. [PMID: 31405281 DOI: 10.1021/acsami.9b07112] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this work, position effects of an alkylthio side chain were investigated by designing and synthesizing two copolymers based on a phenyl-substituted benzo[1,2-b:4,5-b']dithiophene (BDTP) and difluorobenzotriazole (FTAZ). The polymer based on the meta-position-alkylthiolated BDTP, named m-PBDTPS-FTAZ, showed a relatively broader bandgap (2.00 vs 1.96 eV) and lower highest occupied molecular orbital (HOMO) energy level (-5.40 vs -5.32 eV) than its para-positioned structural isomeric analogue polymer (named p-PBDTPS-FTAZ), that is, m- and p-PBDTPS-FTAZ with the side chain structured as ethylhexyl- in the phenyl unit and hexyldecyl- in the FTAZ moiety. When blended with ITIC, m-PBDTPS-FTAZ showed a comparable crystallinity but more uniform morphology compared to that of p-PBDTPS-FTAZ. A high power conversion efficiency of 13.16% was achieved for m-PBDTPS-FTAZ:ITIC devices with a high open circuit voltage (VOC) of 0.95 V, which is higher than that of p-PBDTPS-FTAZ:ITIC devices (10.86%) with a VOC of 0.89 V. Therefore, m-BDTPS could be an effective donor unit to construct high-efficiency polymers due to its effectively decreased HOMO energy level of polymers while still maintaining good molecular stacking.
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Affiliation(s)
- Weichao Chen
- College of Textiles & Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Collaborative Innovation Center for Eco-Textiles of Shandong Province , Qingdao University , Qingdao 266071 , China
| | - Gongyue Huang
- CAS Key Laboratory of Bio-Based Materials , Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao 266101 , China
| | - Xiaoming Li
- CAS Key Laboratory of Bio-Based Materials , Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao 266101 , China
| | - Yonghai Li
- CAS Key Laboratory of Bio-Based Materials , Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao 266101 , China
| | - Huan Wang
- College of Textiles & Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Collaborative Innovation Center for Eco-Textiles of Shandong Province , Qingdao University , Qingdao 266071 , China
| | - Huanxiang Jiang
- CAS Key Laboratory of Bio-Based Materials , Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao 266101 , China
| | - Zhihui Zhao
- College of Textiles & Clothing, State Key Laboratory of Bio-Fibers and Eco-Textiles, Collaborative Innovation Center for Eco-Textiles of Shandong Province , Qingdao University , Qingdao 266071 , China
| | - Donghong Yu
- Department of Chemistry and Bioscience , Aalborg University , Aalborg DK-9220 , Denmark
- Sino-Danish Centre for Education and Research , Aarhus DK-8000 , Denmark
| | - Ergang Wang
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , Göteborg SE-412 96 , Sweden
| | - Renqiang Yang
- CAS Key Laboratory of Bio-Based Materials , Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao 266101 , China
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Cooke K, Browning DF, Lee DJ, Blair JMA, McNeill HE, Huber D, Busby SJW, Bryant JA. Position effects on promoter activity in Escherichia coli and their consequences for antibiotic-resistance determinants. Biochem Soc Trans 2019; 47:839-45. [PMID: 31189732 DOI: 10.1042/BST20180503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 02/07/2023]
Abstract
The activity of any bacterial promoter is generally supposed to be set by its base sequence and the different transcription factors that bind in the local vicinity. Here, we review recent data indicating that the activity of the Escherichia coli lac operon promoter also depends upon its chromosomal location. Factors that affect promoter activity include the binding of nucleoid-associated proteins to neighbouring sequences, supercoiling and the activity of neighbouring promoters. We suggest that many bacterial promoters might be susceptible to similar position-dependent effects and we review recent data showing that the expression of mobile genes encoding antibiotic-resistance determinants is also location-dependent, both when carried on a bacterial chromosome or a conjugative plasmid.
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Zepeda-Mendoza CJ, Menon S, Morton CC. Computational Prediction of Position Effects of Human Chromosome Rearrangements. Curr Protoc Hum Genet 2018; 97:e57. [PMID: 30038699 PMCID: PMC6054318 DOI: 10.1002/cphg.57] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Balanced and apparently balanced chromosome abnormalities (BCAs) have long been known to generate disease through position effects, either by altering local networks of gene regulation or positioning genes in architecturally different chromosome domains. Despite these observations, identification of distally affected genes by BCAs is oftentimes neglected, especially when predicted gene disruptions are found elsewhere in the genome. In this unit, we provide detailed instructions on how to run a computational pipeline that identifies relevant candidates of non-coding BCA position effects. This methodology facilitates quick identification of genes potentially involved in disease by non-coding BCAs and other types of rearrangements, and expands on the importance of considering the long-range consequences of genomic lesions.
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Affiliation(s)
- Cinthya J. Zepeda-Mendoza
- Laboratory Genetics and Genomics, Mayo Clinic School of Graduate Medical Education, Mayo Clinic, Rochester, MN 55902, USA
| | - Shreya Menon
- Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Cynthia C. Morton
- Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women’s Hospital, Boston, MA 02115, USA,Harvard Medical School, Boston, MA 02115, USA,Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA02142, USA,Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02115, USA,Division of Evolution and Genomic Science, School of Biological Sciences, Manchester Academic Health Science Centre, Manchester M13 9NT, UK,Corresponding author
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Carballar-Lejarazú R, Brennock P, James AA. Suppressor of hairy-wing, modifier of mdg4 and centrosomal protein of 190 gene orthologues of the gypsy insulator complex in the malaria mosquito, Anopheles stephensi. Insect Mol Biol 2016; 25:460-469. [PMID: 27110891 PMCID: PMC4935592 DOI: 10.1111/imb.12233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
DNA insulators organize independent gene regulatory domains and can regulate interactions amongst promoter and enhancer elements. They have the potential to be important in genome enhancing and editing technologies because they can mitigate chromosomal position effects on transgenes. The orthologous genes of the Anopheles stephensi putative gypsy-like insulator protein complex were identified and expression characteristics studied. These genes encode polypeptides with all the expected protein domains (Cysteine 2 Histidine 2 (C2H2) zinc fingers and/or a bric-a-brac/poxvirus and zinc finger). The mosquito gypsy transcripts are expressed constitutively and are upregulated in ovaries of blood-fed females. We have uncovered significant experimental evidence that the gypsy insulator protein complex is widespread in vector mosquitoes.
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Affiliation(s)
- R Carballar-Lejarazú
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - P Brennock
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - A A James
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA, USA
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Abstract
The selection of an appropriate booklet design is an important element of large-scale assessments of student achievement. Two design properties that are typically optimized are the balance with respect to the positions the items are presented and with respect to the mutual occurrence of pairs of items in the same booklet. The purpose of this study is to investigate the effects of these two design properties on bias and root mean square error of item parameter estimates from the Rasch model. First, position effects are estimated using data from a large-scale assessment study measuring the competencies of 19,107 ninth graders in science. These results were then used for a simulation study with 1,540 booklet designs with systematically varied position balance and cluster pair balance. The simulation results showed a small effect of position balancing on bias and root mean square error of the item parameter estimates while the cluster pair balance was ignorable. This null effect is actually good news for test designers since it allows for deliberately reducing the degree of cluster pair balance without negative effects on item parameter estimates. However, it is recommended to try to achieve a high position balance when designing large-scale assessment studies.
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Affiliation(s)
| | | | | | - Andreas Frey
- Friedrich Schiller University Jena, Jena, Germany
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Abstract
The injection of a non-isobaric local anesthetic should induce a unilateral spinal anesthesia in patients in a lateral decubitus position. The posterior spinal hemianesthesia only be obtained with hypobaric solutions injected in the jackknife position. The most important factors to be considered when performing a spinal hemianesthesia are: type and gauge of the needle, density of the local anesthetic relative to the CSF, position of the patient, speed of administration of the solution, time of stay in position, and dose/concentration/volume of the anesthetic solution. The distance between the spinal roots on the right-left sides and anterior-posterior is, approximately, 10-15 mm. This distance allows performing unilateral spinal anesthesia or posterior spinal anesthesia. The great advantage of obtaining spinal hemianesthesia is the reduction of cardiovascular changes. Likewise, both the dorsal and unilateral sensory block predominates in relation to the motor block. Because of the numerous advantages of producing spinal hemianesthesia, anesthesiologists should apply this technique more often. This review considers the factors which are relevant, plausible and proven to obtain spinal hemianesthesia.
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Affiliation(s)
- Luiz Eduardo Imbelloni
- Faculdade de Medicina Nova Esperança, Rua Marieta Steinbach Silva, 101/1001, Cabo Branco, João Pessoa, PB - 58043-320, Brazil
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Abstract
Generation and characterization of transgenic mice are important elements of biomedical research. In recent years, transgenic technology has become more versatile and sophisticated, mainly because of the incorporation of recombinase-mediated conditional expression and targeted insertion, site-specific endonuclease-mediated genome editing, siRNA-mediated gene knockdown, various inducible gene expression systems, and fluorescent protein marking and tracking techniques. Site-specific recombinases (such as PhiC31) and engineered endonucleases (such as ZFN and Talen) have significantly enhanced our ability to target transgenes into specific genomic loci, but currently a great majority of transgenic mouse lines are continuingly being created using the conventional random insertion method. A major challenge for using this conventional method is that the genomic environment at the integration site has a substantial influence on the expression of the transgene. Although our understanding of such chromosomal position effects and our means to combat them are still primitive, adhering to some general guidelines can significantly increase the odds of successful transgene expression. This chapter first discusses the major problems associated with transgene expression, and then describes some of the principles for using plasmid and bacterial artificial chromosomes (BACs) for generating transgenic constructs. Finally, the strategies for conducting each of the major types of transgenic research are discussed, including gene overexpression, promoter characterization, cell-lineage tracing, mutant complementation, expression of double or multiple transgenes, siRNA knockdown, and conditional and inducible systems.
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Affiliation(s)
- Lita A. Freeman
- grid.279885.90000000122934638Pulmonary & Vascular Medicine Branch, National Institutes of Health (NIH) National Heart, Lung & Blood Institute, Bethesda, Maryland USA
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Torices R, Méndez M, Gómez JM. Where do monomorphic sexual systems fit in the evolution of dioecy? Insights from the largest family of angiosperms. New Phytol 2011; 190:234-248. [PMID: 21219336 DOI: 10.1111/j.1469-8137.2010.03609.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A range of hypothesized evolutionary pathways has been proposed for describing the evolution of dioecy. However, the evolutionary links between other sexual systems not directly involved in dioecy evolution remain largely unexplored, and hence, a comprehensive picture of evolutionary transitions between sexual systems is still lacking. Here, we explored the diversity and evolution of sexual systems in Asteraceae, the largest family of flowering plants, where almost all sexual systems are present. We used a phylogenetic approach to build a model of evolutionary transitions between sexual systems. The best model involved nine transitions, including those from hermaphroditism to andromonoecy, gynomonoecy and gynodioecy, those from gynomonoecy to monoecy and trimonoecy, two transitions to dioecy -one through gynodioecy and the other through monoecy - and reversals from monoecy to gynomonoecy and from gynomonoecy to hermaphroditism. Our reconstruction of the evolution of sexual systems in Asteraceae provided, for the first time, a joint view of the evolutionary transitions between seven sexual systems, unveiling the evolutionary links between monomorphic sexual systems. A pathway from hermaphroditism to monoecy through gynomonoecy, instead of from andromonoecy, was highly supported, which was consistent with a gradient of floral gender specialization.
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Affiliation(s)
- Rubén Torices
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Móstoles-Madrid, Spain
- Área de Botánica, Departamento de Ciencias Agroforestales, Universidad de Valladolid, Soria, Spain
| | - Marcos Méndez
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Móstoles-Madrid, Spain
| | - José María Gómez
- Departamento de Ecología, Universidad de Granada, Granada, Spain
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Abstract
Lentiviruses are capable of infecting many cells irrespective of their cycling status, stably inserting DNA copies of the viral RNA genomes into host chromosomes. This property has led to the development of lentiviral vectors for high-efficiency gene transfer to a wide variety of cell types, from slowly proliferating hematopoietic stem cells to terminally differentiated neurons. Regardless of their advantage over gammaretroviral vectors, which can only introduce transgenes into target cells that are actively dividing, lentiviral vectors are still susceptible to chromosomal position effects that result in transgene silencing or variegated expression. In this chapter, various genetic regulatory elements are described that can be incorporated within lentiviral vector backbones to minimize the influences of neighboring chromatin on single-copy transgene expression. The modifications include utilization of strong internal enhancer-promoter sequences, addition of scaffold/matrix attachment regions, and flanking the transcriptional unit with chromatin domain insulators. Protocols are provided to evaluate the performance as well as the relative biosafety of lentiviral vectors containing these elements.
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Affiliation(s)
- Ali Ramezani
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC, USA
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