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(1 - 8 of 8)
- Title
- Allele-specific Control Of Replication Timing And Genome Organization During Development.
- Creator
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Rivera-Mulia, Juan Carlos, Dimond, Andrew, Vera, Daniel, Trevilla-Garcia, Claudia, Sasaki, Takayo, Zimmerman, Jared, Dupont, Catherine, Gribnau, Joost, Fraser, Peter, Gilbert,...
Show moreRivera-Mulia, Juan Carlos, Dimond, Andrew, Vera, Daniel, Trevilla-Garcia, Claudia, Sasaki, Takayo, Zimmerman, Jared, Dupont, Catherine, Gribnau, Joost, Fraser, Peter, Gilbert, David M.
Show less - Abstract/Description
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DNA replication occurs in a defined temporal order known as the replication-timing (RT) program. RT is regulated during development in discrete chromosomal units, coordinated with transcriptional activity and 3D genome organization. Here, we derived distinct cell types from F1 hybrid musculus x castaneus mouse crosses and exploited the high single-nucleotide polymorphism (SNP) density to characterize allelic differences in RT (Repli-seq), genome organization (Hi-C and promoter-capture Hi-C),...
Show moreDNA replication occurs in a defined temporal order known as the replication-timing (RT) program. RT is regulated during development in discrete chromosomal units, coordinated with transcriptional activity and 3D genome organization. Here, we derived distinct cell types from F1 hybrid musculus x castaneus mouse crosses and exploited the high single-nucleotide polymorphism (SNP) density to characterize allelic differences in RT (Repli-seq), genome organization (Hi-C and promoter-capture Hi-C), gene expression (total nuclear RNA-seq), and chromatin accessibility (ATAC-seq). We also present HARP, a new computational tool for sorting SNPs in phased genomes to efficiently measure allele-specific genome-wide data. Analysis of six different hybrid mESC clones with different genomes (C57BL/ 6,129 /sv, and CAST/ Ei), parental configurations, and gender revealed significant RT asynchrony between alleles across similar to 12% of the autosomal genome linked to subspecies genomes but not to parental origin, growth conditions, or gender. RT asynchrony in mESCs strongly correlated with changes in Hi-C compartments between alleles but not as strongly with SNP density, gene expression, imprinting, or chromatin accessibility. We then tracked mESC RT asynchronous regions during development by analyzing differentiated cell types, including extraembryonic endoderm stem (XEN) cells, four male and female primary mouse embryonic fibroblasts (MEFs), and neural precursor cells (NPCs) differentiated in vitro from mESCs with opposite parental configurations. We found that RT asynchrony and allelic discordance in Hi-C compartments seen in mESCs were largely lost in all differentiated cell types, accompanied by novel sites of allelic asynchrony at a considerably smaller proportion of the genome, suggesting that genome organization of homologs converges to similar folding patterns during cell fate commitment.
Show less - Date Issued
- 2018-06-01
- Identifier
- FSU_libsubv1_wos_000436084800005, 10.1101/gr.232561.117
- Format
- Citation
- Title
- Genetic Dissection of Dual Roles for the Transcription Factor six7 in Photoreceptor Development and Patterning in Zebrafish.
- Creator
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Sotolongo-Lopez, Mailin, Alvarez-Delfin, Karen, Saade, Carole J., Vera, Daniel L., Fadool, James M.
- Abstract/Description
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The visual system of a particular species is highly adapted to convey detailed ecological and behavioral information essential for survival. The consequences of structural mutations of opsins upon spectral sensitivity and environmental adaptation have been studied in great detail, but lacking is knowledge of the potential influence of alterations in gene regulatory networks upon the diversity of cone subtypes and the variation in the ratio of rods and cones observed in numerous diurnal and...
Show moreThe visual system of a particular species is highly adapted to convey detailed ecological and behavioral information essential for survival. The consequences of structural mutations of opsins upon spectral sensitivity and environmental adaptation have been studied in great detail, but lacking is knowledge of the potential influence of alterations in gene regulatory networks upon the diversity of cone subtypes and the variation in the ratio of rods and cones observed in numerous diurnal and nocturnal species. Exploiting photoreceptor patterning in cone-dominated zebrafish, we uncovered two independent mechanisms by which the sine oculis homeobox homolog 7 (six7) regulates photoreceptor development. In a genetic screen, we isolated the lots-of-rods-junior (ljr(p23ahub)) mutation that resulted in an increased number and uniform distribution of rods in otherwise normal appearing larvae. Sequence analysis, genome editing using TALENs and knockdown strategies confirm ljr(p23ahub) as a hypomorphic allele of six7, a teleost orthologue of six3, with known roles in forebrain patterning and expression of opsins. Based on the lack of predicted protein-coding changes and a deletion of a conserved element upstream of the transcription start site, a cis-regulatory mutation is proposed as the basis of the reduced expression of six7 in ljr(p23ahub). Comparison of the phenotypes of the hypomorphic and knock-out alleles provides evidence of two independent roles in photoreceptor development. EdU and PH3 labeling show that the increase in rod number is associated with extended mitosis of photoreceptor progenitors, and TUNEL suggests that the lack of green-sensitive cones is the result of cell death of the cone precursor. These data add six7 to the small but growing list of essential genes for specification and patterning of photoreceptors in non-mammalian vertebrates, and highlight alterations in transcriptional regulation as a potential source of photoreceptor variation across species.
Show less - Date Issued
- 2016-04
- Identifier
- FSU_libsubv1_wos_000375231900020, 10.1371/journal.pgen.1005968
- Format
- Citation
- Title
- Genetic Dissection of Dual Roles for the Transcription Factor six7 in Photoreceptor Development and Patterning in Zebrafish.
- Creator
-
Sotolongo-Lopez, Mailin, Alvarez-Delfin, Karen, Saade, Carole J, Vera, Daniel L, Fadool, James M
- Abstract/Description
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The visual system of a particular species is highly adapted to convey detailed ecological and behavioral information essential for survival. The consequences of structural mutations of opsins upon spectral sensitivity and environmental adaptation have been studied in great detail, but lacking is knowledge of the potential influence of alterations in gene regulatory networks upon the diversity of cone subtypes and the variation in the ratio of rods and cones observed in numerous diurnal and...
Show moreThe visual system of a particular species is highly adapted to convey detailed ecological and behavioral information essential for survival. The consequences of structural mutations of opsins upon spectral sensitivity and environmental adaptation have been studied in great detail, but lacking is knowledge of the potential influence of alterations in gene regulatory networks upon the diversity of cone subtypes and the variation in the ratio of rods and cones observed in numerous diurnal and nocturnal species. Exploiting photoreceptor patterning in cone-dominated zebrafish, we uncovered two independent mechanisms by which the sine oculis homeobox homolog 7 (six7) regulates photoreceptor development. In a genetic screen, we isolated the lots-of-rods-junior (ljrp23ahub) mutation that resulted in an increased number and uniform distribution of rods in otherwise normal appearing larvae. Sequence analysis, genome editing using TALENs and knockdown strategies confirm ljrp23ahub as a hypomorphic allele of six7, a teleost orthologue of six3, with known roles in forebrain patterning and expression of opsins. Based on the lack of predicted protein-coding changes and a deletion of a conserved element upstream of the transcription start site, a cis-regulatory mutation is proposed as the basis of the reduced expression of six7 in ljrp23ahub. Comparison of the phenotypes of the hypomorphic and knock-out alleles provides evidence of two independent roles in photoreceptor development. EdU and PH3 labeling show that the increase in rod number is associated with extended mitosis of photoreceptor progenitors, and TUNEL suggests that the lack of green-sensitive cones is the result of cell death of the cone precursor. These data add six7 to the small but growing list of essential genes for specification and patterning of photoreceptors in non-mammalian vertebrates, and highlight alterations in transcriptional regulation as a potential source of photoreceptor variation across species.
Show less - Date Issued
- 2016-04-08
- Identifier
- FSU_pmch_27058886, 10.1371/journal.pgen.1005968, PMC4825938, 27058886, 27058886, PGENETICS-D-15-02805
- Format
- Citation
- Title
- An Hpsc-derived Tissue-resident Macrophage Model Reveals Differential Responses Of Macrophages To Zikv And Deny Infection.
- Creator
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Lang, Jianshe, Cheng, Yichen, Rolfe, Alyssa, Hammack, Christy, Vera, Daniel, Kyle, Kathleen, Wang, Jingying, Meissner, Torsten B., Ren, Yi, Cowan, Chad, Tang, Hengli
- Abstract/Description
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Zika virus (ZIKV) and dengue virus (DENV) are two closely related flaviviruses that lead to different clinical outcomes. The mechanism for the distinct pathogenesis of ZIKV and DENV is poorly understood. Here, we investigate ZIKV and DENV infection of macrophages using a human pluripotent stem cell (hPSC)-derived macrophage model and discover key virus-specific responses. ZIKV and DENV productively infect hPSC-derived macrophages. DENV, but not ZIKV, infection of macrophages strongly...
Show moreZika virus (ZIKV) and dengue virus (DENV) are two closely related flaviviruses that lead to different clinical outcomes. The mechanism for the distinct pathogenesis of ZIKV and DENV is poorly understood. Here, we investigate ZIKV and DENV infection of macrophages using a human pluripotent stem cell (hPSC)-derived macrophage model and discover key virus-specific responses. ZIKV and DENV productively infect hPSC-derived macrophages. DENV, but not ZIKV, infection of macrophages strongly activates macrophage migration inhibitory factor (MIF) secretion and decreases macrophage migration. Neutralization of MIF leads to improved migratory ability of DENV-infected macrophages. In contrast, ZIKV-infected macrophages exhibit prolonged migration and express low levels of pro-inflammatory cytokines and chemokines. Mechanistically, ZIKV disrupts the nuclear factor kappa B (NF-kappa B)-MIF positive feedback loop by inhibiting the NF-kappa B signaling pathway. Our results demonstrate the utility of hPSC-derived macrophages in infectious disease modeling and suggest that the distinct impact of ZIKV and DENV on macrophage immune response may underlie different pathogenesis of Zika and dengue diseases.
Show less - Date Issued
- 2018-08-14
- Identifier
- FSU_libsubv1_wos_000441583100006, 10.1016/j.stemcr.2018.06.006
- Format
- Citation
- Title
- Modeling Dengue Virus-Hepatic Cell Interactions Using Human Pluripotent Stem Cell-Derived Hepatocyte-like Cells.
- Creator
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Lang, Jianshe, Vera, Daniel, Cheng, Yichen, Tang, Hengli
- Abstract/Description
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The development of dengue antivirals and vaccine has been hampered by the incomplete understanding of molecular mechanisms of dengue virus (DENV) infection and pathology, partly due to the limited suitable cell culture or animal models that can capture the comprehensive cellular changes induced by DENV. In this study, we differentiated human pluripotent stem cells (hPSCs) into hepatocytes, one of the target cells of DENV, to investigate various aspects of DENV-hepatocyte interaction. hPSC...
Show moreThe development of dengue antivirals and vaccine has been hampered by the incomplete understanding of molecular mechanisms of dengue virus (DENV) infection and pathology, partly due to the limited suitable cell culture or animal models that can capture the comprehensive cellular changes induced by DENV. In this study, we differentiated human pluripotent stem cells (hPSCs) into hepatocytes, one of the target cells of DENV, to investigate various aspects of DENV-hepatocyte interaction. hPSC-derived hepatocyte-like cells (HLCs) supported persistent and productive DENV infection. The activation of interferon pathways by DENV protected bystander cells from infection and protected the infected cells from massive apoptosis. Furthermore, DENV infection activated the NF-κB pathway, which led to production of proinflammatory cytokines and downregulated many liver-specific genes such as albumin and coagulation factor V. Our study demonstrates the utility of hPSC-derived hepatocytes as an in vitro model for DENV infection and reveals important aspects of DENV-host interactions.
Show less - Date Issued
- 2016-09-13
- Identifier
- FSU_pmch_27546535, 10.1016/j.stemcr.2016.07.012, PMC5031989, 27546535, 27546535, S2213-6711(16)30136-9
- Format
- Citation
- Title
- Open chromatin reveals the functional maize genome.
- Creator
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Rodgers-Melnick, Eli, Vera, Daniel L, Bass, Hank W, Buckler, Edward S
- Abstract/Description
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Cellular processes mediated through nuclear DNA must contend with chromatin. Chromatin structural assays can efficiently integrate information across diverse regulatory elements, revealing the functional noncoding genome. In this study, we use a differential nuclease sensitivity assay based on micrococcal nuclease (MNase) digestion to discover open chromatin regions in the maize genome. We find that maize MNase-hypersensitive (MNase HS) regions localize around active genes and within...
Show moreCellular processes mediated through nuclear DNA must contend with chromatin. Chromatin structural assays can efficiently integrate information across diverse regulatory elements, revealing the functional noncoding genome. In this study, we use a differential nuclease sensitivity assay based on micrococcal nuclease (MNase) digestion to discover open chromatin regions in the maize genome. We find that maize MNase-hypersensitive (MNase HS) regions localize around active genes and within recombination hotspots, focusing biased gene conversion at their flanks. Although MNase HS regions map to less than 1% of the genome, they consistently explain a remarkably large amount (∼40%) of heritable phenotypic variance in diverse complex traits. MNase HS regions are therefore on par with coding sequences as annotations that demarcate the functional parts of the maize genome. These results imply that less than 3% of the maize genome (coding and MNase HS regions) may give rise to the overwhelming majority of phenotypic variation, greatly narrowing the scope of the functional genome.
Show less - Date Issued
- 2016-05-31
- Identifier
- FSU_pmch_27185945, 10.1073/pnas.1525244113, PMC4896728, 27185945, 27185945, 1525244113
- Format
- Citation
- Title
- Replicating Large Genomes: Divide and Conquer..
- Creator
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Rivera-Mulia, Juan Carlos, Gilbert, David M
- Abstract/Description
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Complete duplication of large metazoan chromosomes requires thousands of potential initiation sites, only a small fraction of which are selected in each cell cycle. Assembly of the replication machinery is highly conserved and tightly regulated during the cell cycle, but the sites of initiation are highly flexible, and their temporal order of firing is regulated at the level of large-scale multi-replicon domains. Importantly, the number of replication forks must be quickly adjusted in...
Show moreComplete duplication of large metazoan chromosomes requires thousands of potential initiation sites, only a small fraction of which are selected in each cell cycle. Assembly of the replication machinery is highly conserved and tightly regulated during the cell cycle, but the sites of initiation are highly flexible, and their temporal order of firing is regulated at the level of large-scale multi-replicon domains. Importantly, the number of replication forks must be quickly adjusted in response to replication stress to prevent genome instability. Here we argue that large genomes are divided into domains for exactly this reason. Once established, domain structure abrogates the need for precise initiation sites and creates a scaffold for the evolution of other chromosome functions.
Show less - Date Issued
- 2016-06-02
- Identifier
- FSU_pmch_27259206, 10.1016/j.molcel.2016.05.007, PMC4893193, 27259206, 27259206, S1097-2765(16)30144-7
- Format
- Citation
- Title
- Stability of patient-specific features of altered DNA replication timing in xenografts of primary human acute lymphoblastic leukemia.
- Creator
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Sasaki, Takayo, Rivera-Mulia, Juan Carlos, Vera, Daniel, Zimmerman, Jared, Das, Sunny, Padget, Michelle, Nakamichi, Naoto, Chang, Bill H, Tyner, Jeff, Druker, Brian J, Weng,...
Show moreSasaki, Takayo, Rivera-Mulia, Juan Carlos, Vera, Daniel, Zimmerman, Jared, Das, Sunny, Padget, Michelle, Nakamichi, Naoto, Chang, Bill H, Tyner, Jeff, Druker, Brian J, Weng, Andrew P, Civin, Curt I, Eaves, Connie J, Gilbert, David M
Show less - Abstract/Description
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Genome-wide DNA replication timing (RT) profiles reflect the global three-dimensional chromosome architecture of cells. They also provide a comprehensive and unique megabase-scale picture of cellular epigenetic state. Thus, normal differentiation involves reproducible changes in RT, and transformation generally perturbs these, although the potential effects of altered RT on the properties of transformed cells remain largely unknown. A major challenge to interrogating these issues in human...
Show moreGenome-wide DNA replication timing (RT) profiles reflect the global three-dimensional chromosome architecture of cells. They also provide a comprehensive and unique megabase-scale picture of cellular epigenetic state. Thus, normal differentiation involves reproducible changes in RT, and transformation generally perturbs these, although the potential effects of altered RT on the properties of transformed cells remain largely unknown. A major challenge to interrogating these issues in human acute lymphoid leukemia (ALL) is the low proliferative activity of most of the cells, which may be further reduced in cryopreserved samples and difficult to overcome in vitro. In contrast, the ability of many human ALL cell populations to expand when transplanted into highly immunodeficient mice is well documented. To examine the stability of DNA RT profiles of serially passaged xenografts of primary human B- and T-ALL cells, we first devised a method that circumvents the need for bromodeoxyuridine incorporation to distinguish early versus late S-phase cells. Using this and more standard protocols, we found consistently strong retention in xenografts of the original patient-specific RT features. Moreover, in a case in which genomic analyses indicated changing subclonal dynamics in serial passages, the RT profiles tracked concordantly. These results indicate that DNA RT is a relatively stable feature of human ALLs propagated in immunodeficient mice. In addition, they suggest the power of this approach for future interrogation of the origin and consequences of altered DNA RT in ALL.
Show less - Date Issued
- 2017-07-01
- Identifier
- FSU_pmch_28433605, 10.1016/j.exphem.2017.04.004, PMC5491210, 28433605, 28433605, S0301-472X(17)30136-4
- Format
- Citation
