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Leonard AS, Mapel XM, Pausch H. Pangenome-genotyped structural variation improves molecular phenotype mapping in cattle. Genome Res 2024; 34:300-309. [PMID: 38355307 PMCID: PMC10984387 DOI: 10.1101/gr.278267.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 02/01/2024] [Indexed: 02/16/2024]
Abstract
Expression and splicing quantitative trait loci (e/sQTL) are large contributors to phenotypic variability. Achieving sufficient statistical power for e/sQTL mapping requires large cohorts with both genotypes and molecular phenotypes, and so, the genomic variation is often called from short-read alignments, which are unable to comprehensively resolve structural variation. Here we build a pangenome from 16 HiFi haplotype-resolved cattle assemblies to identify small and structural variation and genotype them with PanGenie in 307 short-read samples. We find high (>90%) concordance of PanGenie-genotyped and DeepVariant-called small variation and confidently genotype close to 21 million small and 43,000 structural variants in the larger population. We validate 85% of these structural variants (with MAF > 0.1) directly with a subset of 25 short-read samples that also have medium coverage HiFi reads. We then conduct e/sQTL mapping with this comprehensive variant set in a subset of 117 cattle that have testis transcriptome data, and find 92 structural variants as causal candidates for eQTL and 73 for sQTL. We find that roughly half of the top associated structural variants affecting expression or splicing are transposable elements, such as SV-eQTL for STN1 and MYH7 and SV-sQTL for CEP89 and ASAH2 Extensive linkage disequilibrium between small and structural variation results in only 28 additional eQTL and 17 sQTL discovered when including SVs, although many top associated SVs are compelling candidates.
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Affiliation(s)
| | - Xena M Mapel
- Animal Genomics, ETH Zurich, 8092 Zurich, Switzerland
| | - Hubert Pausch
- Animal Genomics, ETH Zurich, 8092 Zurich, Switzerland
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2
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Zuo Z. The successive emergence of ERVL-MaLRs in primates. Virus Evol 2023; 9:vead072. [PMID: 38131004 PMCID: PMC10735291 DOI: 10.1093/ve/vead072] [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: 09/06/2023] [Revised: 11/01/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023] Open
Abstract
Although the ERVL-mammalian-apparent LTR retrotransposons (MaLRs) are the fourth largest family of transposable elements in the human genome, their evolutionary history and relationship have not been thoroughly studied. In this study, through RepeatMasker annotations of some representative species and construction of phylogenetic tree by sequence similarity, all primate-specific MaLR members are found to descend from MLT1A1 retrotransposon. Comparative genomic analysis, transposition-in-transposition inference, and sequence feature comparisons consistently show that each MaLR member evolved from its predecessor successively and had a limited activity period during primate evolution. Accordingly, a novel MaLR member was discovered as successor of MSTB1 in Tarsiiformes. At last, the identification of candidate precursor and intermediate THE1A elements provides further evidence for the previously proposed arms race model between ZNF430/ZNF100 and THE1B/THE1A. Taken together, this study sheds light on the evolutionary history of MaLRs and can serve as a foundation for future research on their interactions with zinc finger genes, gene regulation, and human health implications.
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Affiliation(s)
- Zheng Zuo
- School of Life Science and Technology, Southeast University, Nanjing 210096, China
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3
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Li Y, Fan H, Qin W, Wang Y, Chen S, Bao W, Sun MA. Regulation of the three-dimensional chromatin organization by transposable elements in pig spleen. Comput Struct Biotechnol J 2023; 21:4580-4588. [PMID: 37790243 PMCID: PMC10542605 DOI: 10.1016/j.csbj.2023.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/23/2023] [Accepted: 09/23/2023] [Indexed: 10/05/2023] Open
Abstract
Like other mammalian species, the pig genome is abundant with transposable elements (TEs). The importance of TEs for three-dimensional (3D) chromatin organization has been observed in species like human and mouse, yet current understanding about pig TEs is absent. Here, we investigated the contribution of TEs for the 3D chromatin organization in three pig tissues, focusing on spleen which is crucial for both adaptive and innate immunity. We identified dozens of TE families overrepresented with CTCF binding sites, including LTR22_SS, LTR15_SS and LTR16_SSc which are pig-specific families of endogenous retroviruses (ERVs). Interestingly, LTR22_SS elements harbor a CTCF motif and create hundreds of CTCF binding sites that are associated with adaptive immunity. We further applied Hi-C to profile the 3D chromatin structure in spleen and found that TE-derived CTCF binding sites correlate with chromatin insulation and frequently overlap TAD borders and loop anchors. Notably, one LTR22_SS-derived CTCF binding site demarcate a TAD boundary upstream of XCL1, which is a spleen-enriched chemokine gene important for lymphocyte trafficking and inflammation. Overall, this study represents a first step toward understanding the function of TEs on 3D chromatin organization regulation in pigs and expands our understanding about the functional importance of TEs in mammals.
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Affiliation(s)
- Yuzhuo Li
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Hairui Fan
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Weiyun Qin
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Yejun Wang
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Health Science Center, Shenzhen 518060, China
| | - Shuai Chen
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Wenbin Bao
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, Jiangsu, China
| | - Ming-an Sun
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Joint International Research Laboratory of Important Animal Infectious Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou 225009, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China
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4
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Pasquesi GIM, Allen H, Ivancevic A, Barbachano-Guerrero A, Joyner O, Guo K, Simpson DM, Gapin K, Horton I, Nguyen L, Yang Q, Warren CJ, Florea LD, Bitler BG, Santiago ML, Sawyer SL, Chuong EB. Regulation of human interferon signaling by transposon exonization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.11.557241. [PMID: 37745311 PMCID: PMC10515820 DOI: 10.1101/2023.09.11.557241] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Innate immune signaling is essential for clearing pathogens and damaged cells, and must be tightly regulated to avoid excessive inflammation or autoimmunity. Here, we found that the alternative splicing of exons derived from transposable elements is a key mechanism controlling immune signaling in human cells. By analyzing long-read transcriptome datasets, we identified numerous transposon exonization events predicted to generate functional protein variants of immune genes, including the type I interferon receptor IFNAR2. We demonstrated that the transposon-derived isoform of IFNAR2 is more highly expressed than the canonical isoform in almost all tissues, and functions as a decoy receptor that potently inhibits interferon signaling including in cells infected with SARS-CoV-2. Our findings uncover a primate-specific axis controlling interferon signaling and show how a transposon exonization event can be co-opted for immune regulation.
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Affiliation(s)
- Giulia Irene Maria Pasquesi
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, 80303
| | - Holly Allen
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Atma Ivancevic
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Arturo Barbachano-Guerrero
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Olivia Joyner
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Kejun Guo
- Division of Infectious Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045
| | - David M. Simpson
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Keala Gapin
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Isabella Horton
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Lily Nguyen
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045
| | - Qing Yang
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
- Fred Hutchinson Cancer Research Center, Seattle, WA, 98109
| | - Cody J. Warren
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
- The Ohio State University College of Veterinary Medicine, Columbus, OH, 43210
| | - Liliana D. Florea
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205
| | - Benjamin G. Bitler
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045
| | - Mario L. Santiago
- Division of Infectious Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045
| | - Sara L. Sawyer
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
| | - Edward B. Chuong
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, Boulder, CO, 80309
- Crnic Institute Boulder Branch, BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, 80303
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Zhao P, Peng C, Fang L, Wang Z, Liu GE. Taming transposable elements in livestock and poultry: a review of their roles and applications. Genet Sel Evol 2023; 55:50. [PMID: 37479995 PMCID: PMC10362595 DOI: 10.1186/s12711-023-00821-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/30/2023] [Indexed: 07/23/2023] Open
Abstract
Livestock and poultry play a significant role in human nutrition by converting agricultural by-products into high-quality proteins. To meet the growing demand for safe animal protein, genetic improvement of livestock must be done sustainably while minimizing negative environmental impacts. Transposable elements (TE) are important components of livestock and poultry genomes, contributing to their genetic diversity, chromatin states, gene regulatory networks, and complex traits of economic value. However, compared to other species, research on TE in livestock and poultry is still in its early stages. In this review, we analyze 72 studies published in the past 20 years, summarize the TE composition in livestock and poultry genomes, and focus on their potential roles in functional genomics. We also discuss bioinformatic tools and strategies for integrating multi-omics data with TE, and explore future directions, feasibility, and challenges of TE research in livestock and poultry. In addition, we suggest strategies to apply TE in basic biological research and animal breeding. Our goal is to provide a new perspective on the importance of TE in livestock and poultry genomes.
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Affiliation(s)
- Pengju Zhao
- Hainan Institute of Zhejiang University, Hainan Sanya, 572000, China
- College of Animal Sciences, Zhejiang University, Zhejiang, Hangzhou, People's Republic of China
| | - Chen Peng
- Hainan Institute of Zhejiang University, Hainan Sanya, 572000, China
- College of Animal Sciences, Zhejiang University, Zhejiang, Hangzhou, People's Republic of China
| | - Lingzhao Fang
- Center for Quantitative Genetics and Genomics, Aarhus University, 8000, Aarhus, Denmark.
| | - Zhengguang Wang
- Hainan Institute of Zhejiang University, Hainan Sanya, 572000, China.
- College of Animal Sciences, Zhejiang University, Zhejiang, Hangzhou, People's Republic of China.
| | - George E Liu
- Animal Genomics and Improvement Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, USDA, Beltsville, MD, 20705, USA.
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6
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Nguyen LL, Watson ZL, Ortega R, Woodruff ER, Jordan KR, Iwanaga R, Yamamoto TM, Bailey CA, Jeong AD, Guntupalli SR, Behbakht K, Gbaja V, Arnoult N, Chuong EB, Bitler BG. Combinatory EHMT and PARP inhibition induces an interferon response and a CD8 T cell-dependent tumor regression in PARP inhibitor-resistant models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529773. [PMID: 36865165 PMCID: PMC9980116 DOI: 10.1101/2023.02.23.529773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Euchromatic histone lysine methyltransferases 1 and 2 (EHMT1/2), which catalyze demethylation of histone H3 lysine 9 (H3K9me2), contribute to tumorigenesis and therapy resistance through unknown mechanisms of action. In ovarian cancer, EHMT1/2 and H3K9me2 are directly linked to acquired resistance to poly-ADP-ribose polymerase (PARP) inhibitors and are correlated with poor clinical outcomes. Using a combination of experimental and bioinformatic analyses in several PARP inhibitor resistant ovarian cancer models, we demonstrate that combinatory inhibition of EHMT and PARP is effective in treating PARP inhibitor resistant ovarian cancers. Our in vitro studies show that combinatory therapy reactivates transposable elements, increases immunostimulatory dsRNA formation, and elicits several immune signaling pathways. Our in vivo studies show that both single inhibition of EHMT and combinatory inhibition of EHMT and PARP reduces tumor burden, and that this reduction is dependent on CD8 T cells. Together, our results uncover a direct mechanism by which EHMT inhibition helps to overcome PARP inhibitor resistance and shows how an epigenetic therapy can be used to enhance anti-tumor immunity and address therapy resistance.
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Affiliation(s)
- Lily L. Nguyen
- Molecular Cellular Developmental Biology, The University of Colorado Boulder, Boulder, CO 80309, USA
| | - Zachary L. Watson
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, 80045
| | - Raquel Ortega
- Molecular Cellular Developmental Biology, The University of Colorado Boulder, Boulder, CO 80309, USA
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, 80045
| | - Elizabeth R. Woodruff
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, 80045
| | - Kimberly R. Jordan
- Department of Immunology and Microbiology, The University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ritsuko Iwanaga
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, 80045
| | - Tomomi M. Yamamoto
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, 80045
| | - Courtney A. Bailey
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, 80045
| | - Abigail D. Jeong
- Molecular Cellular Developmental Biology, The University of Colorado Boulder, Boulder, CO 80309, USA
| | - Saketh R. Guntupalli
- Department of Obstetrics & Gynecology, Division of Gynecologic Oncology, The University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Kian Behbakht
- Department of Obstetrics & Gynecology, Division of Gynecologic Oncology, The University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | | | - Nausica Arnoult
- Molecular Cellular Developmental Biology, The University of Colorado Boulder, Boulder, CO 80309, USA
| | - Edward B. Chuong
- Molecular Cellular Developmental Biology, The University of Colorado Boulder, Boulder, CO 80309, USA
| | - Benjamin G. Bitler
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, CO, 80045
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7
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Inhibition of EZH2 Causes Retrotransposon Derepression and Immune Activation in Porcine Lung Alveolar Macrophages. Int J Mol Sci 2023; 24:ijms24032394. [PMID: 36768720 PMCID: PMC9917017 DOI: 10.3390/ijms24032394] [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: 12/29/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
Alveolar macrophages (AMs) form the first defense line against various respiratory pathogens, and their immune response has a profound impact on the outcome of respiratory infection. Enhancer of zeste homolog 2 (EZH2), which catalyzes the trimethylation of H3K27 for epigenetic repression, has gained increasing attention for its immune regulation function, yet its exact function in AMs remains largely obscure. Using porcine 3D4/21 AM cells as a model, we characterized the transcriptomic and epigenomic alterations after the inhibition of EZH2. We found that the inhibition of EZH2 causes transcriptional activation of numerous immune genes and inhibits the subsequent infection by influenza A virus. Interestingly, specific families of transposable elements, particularly endogenous retrovirus elements (ERVs) and LINEs which belong to retrotransposons, also become derepressed. While some of the derepressed ERV families are pig-specific, a few ancestral families are known to be under EZH2-mediated repression in humans. Given that derepression of ERVs can promote innate immune activation through "viral mimicry", we speculate that ERVs may also contribute to the coinciding immune activation in AMs after the inhibition of EZH2. Overall, this study improves the understanding of the EZH2-related immune regulation in AMs and provides novel insights into the epigenetic regulation of retrotransposons in pigs.
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8
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Pasquesi GIM, Kelly CJ, Ordonez AD, Chuong EB. Transcriptional dynamics of transposable elements in the type I IFN response in Myotis lucifugus cells. Mob DNA 2022; 13:22. [PMID: 36068622 PMCID: PMC9446614 DOI: 10.1186/s13100-022-00277-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 08/09/2022] [Indexed: 12/02/2022] Open
Abstract
Background Bats are a major reservoir of zoonotic viruses, and there has been growing interest in characterizing bat-specific features of innate immunity and inflammation. Recent studies have revealed bat-specific adaptations affecting interferon (IFN) signaling and IFN-stimulated genes (ISGs), but we still have a limited understanding of the genetic mechanisms that have shaped the evolution of bat immunity. Here we investigated the transcriptional and epigenetic dynamics of transposable elements (TEs) during the type I IFN response in little brown bat (Myotis lucifugus) primary embryonic fibroblast cells, using RNA-seq and CUT&RUN. Results We found multiple bat-specific TEs that undergo both locus-specific and family-level transcriptional induction in response to IFN. Our transcriptome reassembly identified multiple ISGs that have acquired novel exons from bat-specific TEs, including NLRC5, SLNF5 and a previously unannotated isoform of the IFITM2 gene. We also identified examples of TE-derived regulatory elements, but did not find strong evidence supporting genome-wide epigenetic activation of TEs in response to IFN. Conclusion Collectively, our study uncovers numerous TE-derived transcripts, proteins, and alternative isoforms that are induced by IFN in Myotis lucifugus cells, highlighting candidate loci that may contribute to bat-specific immune function. Supplementary Information The online version contains supplementary material available at 10.1186/s13100-022-00277-z.
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Affiliation(s)
- Giulia Irene Maria Pasquesi
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, 596 UCB, Boulder, CO, 80309, USA
| | - Conor J Kelly
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, 596 UCB, Boulder, CO, 80309, USA
| | - Andrea D Ordonez
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, 596 UCB, Boulder, CO, 80309, USA
| | - Edward B Chuong
- BioFrontiers Institute and Department of Molecular, Cellular & Developmental Biology, University of Colorado Boulder, 596 UCB, Boulder, CO, 80309, USA.
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