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Bond ML, Davis ES, Quiroga IY, Dey A, Kiran M, Love MI, Won H, Phanstiel DH. Chromatin loop dynamics during cellular differentiation are associated with changes to both anchor and internal regulatory features. Genome Res 2023; 33:1258-1268. [PMID: 37699658 PMCID: PMC10547260 DOI: 10.1101/gr.277397.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 07/07/2023] [Indexed: 09/14/2023]
Abstract
Three-dimensional (3D) chromatin structure has been shown to play a role in regulating gene transcription during biological transitions. Although our understanding of loop formation and maintenance is rapidly improving, much less is known about the mechanisms driving changes in looping and the impact of differential looping on gene transcription. One limitation has been a lack of well-powered differential looping data sets. To address this, we conducted a deeply sequenced Hi-C time course of megakaryocyte development comprising four biological replicates and 6 billion reads per time point. Statistical analysis revealed 1503 differential loops. Gained loop anchors were enriched for AP-1 occupancy and were characterized by large increases in histone H3K27ac (over 11-fold) but relatively small increases in CTCF and RAD21 binding (1.26- and 1.23-fold, respectively). Linear modeling revealed that changes in histone H3K27ac, chromatin accessibility, and JUN binding were better correlated with changes in looping than RAD21 and almost as well correlated as CTCF. Changes to epigenetic features between-rather than at-boundaries were highly predictive of changes in looping. Together these data suggest that although CTCF and RAD21 may be the core machinery dictating where loops form, other features (both at the anchors and within the loop boundaries) may play a larger role than previously anticipated in determining the relative loop strength across cell types and conditions.
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Affiliation(s)
- Marielle L Bond
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Eric S Davis
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Ivana Y Quiroga
- Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Anubha Dey
- Department of Systems and Computational Biology, University of Hyderabad, Hyderabad 500046, Telangana, India
| | - Manjari Kiran
- Department of Systems and Computational Biology, University of Hyderabad, Hyderabad 500046, Telangana, India
| | - Michael I Love
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Hyejung Won
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, USA;
- Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Douglas H Phanstiel
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA;
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Mohandasan R, Thakare M, Sunke S, Iqbal FM, Sridharan M, Das G. Enhanced olfactory memory detection in trap-design Y-mazes allows the study of imperceptible memory traces in Drosophila. Learn Mem 2022; 29:355-366. [PMID: 36180129 PMCID: PMC9536757 DOI: 10.1101/lm.053545.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 07/08/2022] [Indexed: 11/25/2022]
Abstract
The neural basis of behavior is identified by systematically manipulating the activity of specific neurons and screening for loss or gain of phenotype. Therefore, robust, high-scoring behavioral assays are necessary for determining the neural circuits of novel behaviors. We report a simple Y-maze design for Drosophila olfactory learning and memory assay. Memory scores in our Y-mazes are considerably better and longer-lasting than scores obtained with commonly used T-mazes. Our results suggest that trapping flies to an odor choice in a Y-maze could improve scores. We postulated that the improved scores could reveal previously undetectable memory traces, enabling the study of underlying neural mechanisms. Indeed, we identified unreported protein synthesis-dependent long-term memories (LTMs), reinforced by ingestion of (1) an aversive compound and (2) a sweet but nonnutritious sugar, both 24 h after training. We also used Y-mazes to probe how using a greater reward may change memory dynamics. Our findings predict that a greater sugar reward may extend existing memory traces or reinforce additional novel ones.
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Affiliation(s)
- Radhika Mohandasan
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
- Savitribai Phule Pune University, Ganeshkhind, Pune 411007, India
| | - Manikrao Thakare
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
- Savitribai Phule Pune University, Ganeshkhind, Pune 411007, India
| | - Suhas Sunke
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Fathima Mukthar Iqbal
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Madhav Sridharan
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
| | - Gaurav Das
- Brain and Feeding Behavior Laboratory, National Centre for Cell Science, S.P. Pune University Campus, Ganeshkhind, Pune 411007, India
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Nicolson F, Ali A, Kircher MF, Pal S. DNA Nanostructures and DNA-Functionalized Nanoparticles for Cancer Theranostics. Adv Sci (Weinh) 2020; 7:2001669. [PMID: 33304747 PMCID: PMC7709992 DOI: 10.1002/advs.202001669] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/27/2020] [Indexed: 05/12/2023]
Abstract
In the last two decades, DNA has attracted significant attention toward the development of materials at the nanoscale for emerging applications due to the unparalleled versatility and programmability of DNA building blocks. DNA-based artificial nanomaterials can be broadly classified into two categories: DNA nanostructures (DNA-NSs) and DNA-functionalized nanoparticles (DNA-NPs). More importantly, their use in nanotheranostics, a field that combines diagnostics with therapy via drug or gene delivery in an all-in-one platform, has been applied extensively in recent years to provide personalized cancer treatments. Conveniently, the ease of attachment of both imaging and therapeutic moieties to DNA-NSs or DNA-NPs enables high biostability, biocompatibility, and drug loading capabilities, and as a consequence, has markedly catalyzed the rapid growth of this field. This review aims to provide an overview of the recent progress of DNA-NSs and DNA-NPs as theranostic agents, the use of DNA-NSs and DNA-NPs as gene and drug delivery platforms, and a perspective on their clinical translation in the realm of oncology.
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Affiliation(s)
- Fay Nicolson
- Department of ImagingDana‐Farber Cancer Institute & Harvard Medical SchoolBostonMA02215USA
- Center for Molecular Imaging and NanotechnologyMemorial Sloan Kettering Cancer CenterNew YorkNY10065USA
| | - Akbar Ali
- Department of ChemistryIndian Institute of Technology‐ BhilaiRaipurChhattisgarh492015India
| | - Moritz F. Kircher
- Department of ImagingDana‐Farber Cancer Institute & Harvard Medical SchoolBostonMA02215USA
- Center for Molecular Imaging and NanotechnologyMemorial Sloan Kettering Cancer CenterNew YorkNY10065USA
- Department of RadiologyBrigham and Women's Hospital & Harvard Medical SchoolBostonMA02215USA
| | - Suchetan Pal
- Department of ChemistryIndian Institute of Technology‐ BhilaiRaipurChhattisgarh492015India
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