10 results on '"Emily E. Wear"'
Search Results
2. Repliscan: a tool for classifying replication timing regions
- Author
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Gregory J. Zynda, Jawon Song, Lorenzo Concia, Emily E. Wear, Linda Hanley-Bowdoin, William F. Thompson, and Matthew W. Vaughn
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DNA replication ,Repli-seq ,Classification ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background Replication timing experiments that use label incorporation and high throughput sequencing produce peaked data similar to ChIP-Seq experiments. However, the differences in experimental design, coverage density, and possible results make traditional ChIP-Seq analysis methods inappropriate for use with replication timing. Results To accurately detect and classify regions of replication across the genome, we present Repliscan. Repliscan robustly normalizes, automatically removes outlying and uninformative data points, and classifies Repli-seq signals into discrete combinations of replication signatures. The quality control steps and self-fitting methods make Repliscan generally applicable and more robust than previous methods that classify regions based on thresholds. Conclusions Repliscan is simple and effective to use on organisms with different genome sizes. Even with analysis window sizes as small as 1 kilobase, reliable profiles can be generated with as little as 2.4x coverage.
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- 2017
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3. Comparing DNA replication programs reveals large timing shifts at centromeres of endocycling cells in maize roots.
- Author
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Emily E Wear, Jawon Song, Gregory J Zynda, Leigh Mickelson-Young, Chantal LeBlanc, Tae-Jin Lee, David O Deppong, George C Allen, Robert A Martienssen, Matthew W Vaughn, Linda Hanley-Bowdoin, and William F Thompson
- Subjects
Genetics ,QH426-470 - Abstract
Plant cells undergo two types of cell cycles-the mitotic cycle in which DNA replication is coupled to mitosis, and the endocycle in which DNA replication occurs in the absence of cell division. To investigate DNA replication programs in these two types of cell cycles, we pulse labeled intact root tips of maize (Zea mays) with 5-ethynyl-2'-deoxyuridine (EdU) and used flow sorting of nuclei to examine DNA replication timing (RT) during the transition from a mitotic cycle to an endocycle. Comparison of the sequence-based RT profiles showed that most regions of the maize genome replicate at the same time during S phase in mitotic and endocycling cells, despite the need to replicate twice as much DNA in the endocycle and the fact that endocycling is typically associated with cell differentiation. However, regions collectively corresponding to 2% of the genome displayed significant changes in timing between the two types of cell cycles. The majority of these regions are small with a median size of 135 kb, shift to a later RT in the endocycle, and are enriched for genes expressed in the root tip. We found larger regions that shifted RT in centromeres of seven of the ten maize chromosomes. These regions covered the majority of the previously defined functional centromere, which ranged between 1 and 2 Mb in size in the reference genome. They replicate mainly during mid S phase in mitotic cells but primarily in late S phase of the endocycle. In contrast, the immediately adjacent pericentromere sequences are primarily late replicating in both cell cycles. Analysis of CENH3 enrichment levels in 8C vs 2C nuclei suggested that there is only a partial replacement of CENH3 nucleosomes after endocycle replication is complete. The shift to later replication of centromeres and possible reduction in CENH3 enrichment after endocycle replication is consistent with a hypothesis that centromeres are inactivated when their function is no longer needed.
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- 2020
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4. Comparing DNA replication programs reveals large timing shifts at centromeres of endocycling cells in maize roots
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David O. Deppong, Chantal LeBlanc, Tae-Jin Lee, Linda Hanley-Bowdoin, Leigh Mickelson-Young, George Allen, Matthew W. Vaughn, Robert A. Martienssen, Jawon Song, Gregory J Zynda, Emily E. Wear, and William F. Thompson
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Cancer Research ,Cell division ,Cellular differentiation ,Synthesis Phase ,Gene Expression ,Plant Science ,QH426-470 ,Plant Genetics ,Biochemistry ,Plant Roots ,S Phase ,chemistry.chemical_compound ,0302 clinical medicine ,Cell Signaling ,DNA Replication Timing ,Plant Genomics ,Cell Cycle and Cell Division ,Genetics (clinical) ,Centromeres ,0303 health sciences ,Chromosome Biology ,Eukaryota ,Genomics ,Plants ,Cell cycle ,Endocytosis ,Nucleosomes ,Cell biology ,Nucleic acids ,Experimental Organism Systems ,Cell Processes ,Engineering and Technology ,Genomic Signal Processing ,Research Article ,Biotechnology ,Signal Transduction ,DNA Replication ,Chromosome Structure and Function ,DNA, Plant ,Centromere ,Meristem ,Mitosis ,Bioengineering ,Biology ,Research and Analysis Methods ,Zea mays ,Chromosomes ,03 medical and health sciences ,Model Organisms ,Plant and Algal Models ,Genetics ,Nucleosome ,Grasses ,Molecular Biology ,Gene ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Cell Nucleus ,Organisms ,DNA replication ,Biology and Life Sciences ,Cell Biology ,DNA ,Deoxyuridine ,Maize ,chemistry ,Animal Studies ,Plant Biotechnology ,030217 neurology & neurosurgery - Abstract
Plant cells undergo two types of cell cycles–the mitotic cycle in which DNA replication is coupled to mitosis, and the endocycle in which DNA replication occurs in the absence of cell division. To investigate DNA replication programs in these two types of cell cycles, we pulse labeled intact root tips of maize (Zea mays) with 5-ethynyl-2’-deoxyuridine (EdU) and used flow sorting of nuclei to examine DNA replication timing (RT) during the transition from a mitotic cycle to an endocycle. Comparison of the sequence-based RT profiles showed that most regions of the maize genome replicate at the same time during S phase in mitotic and endocycling cells, despite the need to replicate twice as much DNA in the endocycle and the fact that endocycling is typically associated with cell differentiation. However, regions collectively corresponding to 2% of the genome displayed significant changes in timing between the two types of cell cycles. The majority of these regions are small with a median size of 135 kb, shift to a later RT in the endocycle, and are enriched for genes expressed in the root tip. We found larger regions that shifted RT in centromeres of seven of the ten maize chromosomes. These regions covered the majority of the previously defined functional centromere, which ranged between 1 and 2 Mb in size in the reference genome. They replicate mainly during mid S phase in mitotic cells but primarily in late S phase of the endocycle. In contrast, the immediately adjacent pericentromere sequences are primarily late replicating in both cell cycles. Analysis of CENH3 enrichment levels in 8C vs 2C nuclei suggested that there is only a partial replacement of CENH3 nucleosomes after endocycle replication is complete. The shift to later replication of centromeres and possible reduction in CENH3 enrichment after endocycle replication is consistent with a hypothesis that centromeres are inactivated when their function is no longer needed., Author summary In traditional cell division, or mitosis, a cell’s genetic material is duplicated and then split between two daughter cells. In contrast, in some specialized cell types, the DNA is duplicated a second time without an intervening division step, resulting in cells that carry twice as much DNA. This phenomenon, which is called the endocycle, is common during plant development. At each step, DNA replication follows an ordered program in which highly compacted DNA is unraveled and replicated in sections at different times during the synthesis (S) phase. In plants, it is unclear whether traditional and endocycle programs are the same, especially since endocycling cells are typically in the process of differentiation. Using root tips of maize, we found that in comparison to replication in the mitotic cell cycle, there is a small portion of the genome whose replication in the endocycle is shifted in time, usually to later in S phase. Some of these regions are scattered around the genome and mostly coincide with active genes. However, the most prominent shifts occur in centromeres. The shift to later replication in centromeres is noteworthy because they orchestrate the process of separating duplicated chromosomes into daughter cells, a function that is not needed in the endocycle.
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- 2020
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5. Genomic Analysis of the DNA Replication Timing Program during Mitotic S Phase in Maize (Zea mays) Root Tips[OPEN]
- Author
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Emily E. Wear, William F. Thompson, Patrick Mulvaney, George Allen, Gregory J Zynda, Eric S. Szymanski, Lorenzo Concia, Jawon Song, Leigh Mickelson-Young, Chantal LeBlanc, Linda Hanley-Bowdoin, Tae-Jin Lee, Matthew W. Vaughn, and Robert A. Martienssen
- Subjects
0301 basic medicine ,Time Factors ,Transcription, Genetic ,DNA Replication Timing ,Meristem ,Mitosis ,Plant Science ,Biology ,Origin of replication ,Pre-replication complex ,Genes, Plant ,Zea mays ,Chromosomes, Plant ,S Phase ,03 medical and health sciences ,Mitotic cell cycle ,Control of chromosome duplication ,Large-Scale Biology Article ,Genetics ,Replication timing ,Base Sequence ,Models, Genetic ,Cell Biology ,Genomics ,030104 developmental biology ,Tandem Repeat Sequences ,DNA Transposable Elements ,Origin recognition complex ,Mitotic S phase - Abstract
All plants and animals must replicate their DNA, using a regulated process to ensure that their genomes are completely and accurately replicated. DNA replication timing programs have been extensively studied in yeast and animal systems, but much less is known about the replication programs of plants. We report a novel adaptation of the "Repli-seq" assay for use in intact root tips of maize (Zea mays) that include several different cell lineages, and present replication profiles from cells in early, mid, and late S phase of the mitotic cell cycle. This represents the first genomic analysis of replication timing in a crop species, and the first in any plant species to characterize replication at the whole-genome level. Maize root tips have a complex replication timing program, including regions of distinct early, mid and late-S replication that each constitute between 20-24% of the genome, as well as other loci corresponding to ~32% of the genome that exhibit replication activity in two different time windows. Analyses of genomic, transcriptional, and chromatin features of the euchromatic portion of the maize genome provide evidence for a gradient of early replicating, open chromatin that transitions gradually to less open and less transcriptionally active chromatin replicating in mid S phase. Our genomic level analysis also demonstrated that the centromere core replicates in mid S, before heavily compacted classical heterochromatin, including pericentromeres and knobs, which replicate during late S phase.
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- 2017
6. Defining multiple, distinct, and shared spatiotemporal patterns of DNA replication and endoreduplication from 3D image analysis of developing maize (Zea mays L.) root tip nuclei
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Linda Hanley-Bowdoin, Stacey R. Joseph, Hank W. Bass, Tae-Jin Lee, George Allen, Emily E. Wear, Gregg G. Hoffman, and William F. Thompson
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0106 biological sciences ,DNA Replication ,Euchromatin ,DNA, Plant ,Heterochromatin ,DNA Replication Timing ,Meristem ,Plant Science ,Biology ,Cell cycle ,Genes, Plant ,01 natural sciences ,Models, Biological ,Zea mays ,Article ,S Phase ,03 medical and health sciences ,Imaging, Three-Dimensional ,Genetics ,Endoreduplication ,Gene ,Mitosis ,030304 developmental biology ,2. Zero hunger ,Cell Nucleus ,0303 health sciences ,Replication timing ,DNA synthesis ,Grass ,DNA replication ,General Medicine ,Cell biology ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
Spatiotemporal patterns of DNA replication have been described for yeast and many types of cultured animal cells, frequently after cell cycle arrest to aid in synchronization. However, patterns of DNA replication in nuclei from plants or naturally developing organs remain largely uncharacterized. Here we report findings from 3D quantitative analysis of DNA replication and endoreduplication in nuclei from pulse-labeled developing maize root tips. In both early and middle S phase nuclei, flow-sorted on the basis of DNA content, replicative labeling was widely distributed across euchromatic regions of the nucleoplasm. We did not observe the perinuclear or perinucleolar replicative labeling patterns characteristic of middle S phase in mammals. Instead, the early versus middle S phase patterns in maize could be distinguished cytologically by correlating two quantitative, continuous variables, replicative labeling and DAPI staining. Early S nuclei exhibited widely distributed euchromatic labeling preferentially localized to regions with weak DAPI signals. Middle S nuclei also exhibited widely distributed euchromatic labeling, but the label was preferentially localized to regions with strong DAPI signals. Highly condensed heterochromatin, including knobs, replicated during late S phase as previously reported. Similar spatiotemporal replication patterns were observed for both mitotic and endocycling maize nuclei. These results revealed that maize euchromatin exists as an intermingled mixture of two components distinguished by their condensation state and replication timing. These different patterns might reflect a previously described genome organization pattern, with “gene islands” mostly replicating during early S phase followed by most of the intergenic repetitive regions replicating during middle S phase. Electronic supplementary material The online version of this article (doi:10.1007/s11103-015-0364-4) contains supplementary material, which is available to authorized users.
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7. A flow cytometric method for estimating S-phase duration in plants.
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Mickelson-Young L, Wear E, Mulvaney P, Lee TJ, Szymanski ES, Allen G, Hanley-Bowdoin L, and Thompson W
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- Arabidopsis cytology, Arabidopsis growth & development, DNA, Plant metabolism, Deoxyuridine analogs & derivatives, Deoxyuridine metabolism, G1 Phase physiology, G2 Phase physiology, Hordeum cytology, Hordeum growth & development, Meristem cytology, Meristem growth & development, Oryza cytology, Oryza growth & development, Triticum cytology, Triticum growth & development, Zea mays cytology, Zea mays growth & development, Flow Cytometry methods, S Phase physiology
- Abstract
The duration of the DNA synthesis stage (S phase) of the cell cycle is fundamental in our understanding of cell cycle kinetics, cell proliferation, and DNA replication timing programs. Most S-phase duration estimates that exist for plants are based on indirect measurements. We present a method for directly estimating S-phase duration by pulse-labeling root tips or actively dividing suspension cells with the halogenated thymidine analog 5-ethynl-2'-deoxyuridine (EdU) and analyzing the time course of replication with bivariate flow cytometry. The transition between G
1 and G2 DNA contents can be followed by measuring the mean DNA content of EdU-labeled S-phase nuclei as a function of time after the labeling pulse. We applied this technique to intact root tips of maize (Zea mays L.), rice (Oryza sativa L.), barley (Hordeum vulgare L.), and wheat (Triticum aestivum L.), and to actively dividing cell cultures of Arabidopsis (Arabidopsis thaliana (L.) Heynh.) and rice. Estimates of S-phase duration in root tips were remarkably consistent, varying only by ~3-fold, although the genome sizes of the species analyzed varied >40-fold., (© The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.)- Published
- 2016
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8. Randomized controlled trial of brief cognitive behavioral intervention for depression and anxiety symptoms preoperatively in patients undergoing coronary artery bypass graft surgery.
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Dao TK, Youssef NA, Armsworth M, Wear E, Papathopoulos KN, and Gopaldas R
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- Aged, Aged, 80 and over, Coronary Artery Bypass economics, Feasibility Studies, Female, Health Status Indicators, Humans, Length of Stay economics, Middle Aged, Patient Education as Topic, Preoperative Period, Quality of Life, Treatment Outcome, United States, Anxiety therapy, Cognitive Behavioral Therapy methods, Coronary Artery Bypass psychology, Depression therapy
- Abstract
Objective: The goal of this study was to examine the feasibility, acceptability, and efficacy of a brief, tailored cognitive-behavioral intervention for patients with symptoms of preoperative depression or anxiety before undergoing a coronary artery bypass graft (CABG) operation., Methods: Patients were recruited from a university teaching hospital between February 2007 and May 2009. Patients were randomly assigned to receive treatment as usual (TAU) or a cognitive behavioral therapy (CBT) intervention called Managing Anxiety and Depression using Education and Skills (MADES). A total of 100 subjects were randomized into the study. Length of hospital stay was assessed with a 1-way analysis of variance. Depression, anxiety, and quality of life were assessed with mixed-model repeated measures analyses., Results: Overall, the intervention was feasible, and patients had a positive impression of the MADES. Patients in the TAU group stayed longer in the hospital than did those in the MADES group (7.9 days ± 2.6 vs 9.2 days ± 3.5; P = .049). Depressive symptoms increased at time of hospital discharge for the TAU group, whereas the MADES group had a decrease in depressive symptoms at the time of discharge. Quality of life and anxiety symptoms improved in both groups at 3 to 4 weeks of follow-up. However, the MADES group had greater improvements than did the TAU group., Conclusions: This study demonstrated that brief, tailored CBT targeting preoperative depression and anxiety is both feasible and acceptable for patients undergoing CABG surgery. Most important, this intervention improved depressive and anxiety symptoms, as well as quality of life. Moreover, it reduced in-hospital length of stay. This study found that a cognitive-behavioral intervention for patients undergoing CABG surgery for symptoms of preoperative depression/anxiety is both feasible and acceptable. Most important, this intervention improved depressive and anxiety symptoms, as well as quality of life. It also reduced in-hospital length of stay., (Copyright © 2011 The American Association for Thoracic Surgery. All rights reserved.)
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- 2011
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9. Autonomic cardiovascular dysregulation as a potential mechanism underlying depression and coronary artery bypass grafting surgery outcomes.
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Dao TK, Youssef NA, Gopaldas RR, Chu D, Bakaeen F, Wear E, and Menefee D
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- Coronary Disease complications, Coronary Disease physiopathology, Depressive Disorder complications, Heart Rate, Humans, Length of Stay, Norepinephrine blood, Treatment Outcome, Autonomic Nervous System physiopathology, Coronary Artery Bypass psychology, Coronary Disease surgery, Depressive Disorder physiopathology
- Abstract
Background: Coronary artery bypass grafting (CABG) is often used to treat patients with significant coronary heart disease (CHD). To date, multiple longitudinal and cross-sectional studies have examined the association between depression and CABG outcomes. Although this relationship is well established, the mechanism underlying this relationship remains unclear. The purpose of this study was twofold. First, we compared three markers of autonomic nervous system (ANS) function in four groups of patients: 1) Patients with coronary heart disease and depression (CHD/Dep), 2) Patients without CHD but with depression (NonCHD/Dep), 3) Patients with CHD but without depression (CHD/NonDep), and 4) Patients without CHD and depression (NonCHD/NonDep). Second, we investigated the impact of depression and autonomic nervous system activity on CABG outcomes., Methods: Patients were screened to determine whether they met some of the study's inclusion or exclusion criteria. ANS function (i.e., heart rate, heart rate variability, and plasma norepinephrine levels) were measured. Chi-square and one-way analysis of variance were performed to evaluate group differences across demographic, medical variables, and indicators of ANS function. Logistic regression and multiple regression analyses were used to assess impact of depression and autonomic nervous system activity on CABG outcomes., Results: The results of the study provide some support to suggest that depressed patients with CHD have greater ANS dysregulation compared to those with only CHD or depression. Furthermore, independent predictors of in-hospital length of stay and non-routine discharge included having a diagnosis of depression and CHD, elevated heart rate, and low heart rate variability., Conclusions: The current study presents evidence to support the hypothesis that ANS dysregulation might be one of the underlying mechanisms that links depression to cardiovascular CABG surgery outcomes. Thus, future studies should focus on developing and testing interventions that targets modifying ANS dysregulation, which may lead to improved patient outcomes.
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- 2010
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10. Mammography stages of change in middle-aged women with schizophrenia: an exploratory analysis.
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Lindamer LA, Wear E, and Sadler GR
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- Adult, Breast Neoplasms psychology, Female, Health Knowledge, Attitudes, Practice, Health Promotion, Humans, Middle Aged, Predictive Value of Tests, Psychometrics, Social Conditions, Breast Neoplasms diagnostic imaging, Guideline Adherence, Mammography statistics & numerical data, Patient Compliance, Schizophrenic Psychology
- Abstract
Background: Health care providers and educators who seek to create health promotion programs and individualized comprehensive care plans for women with schizophrenia are hindered by the lack of data to guide their efforts., Purpose: This study tested the hypothesis that women with schizophrenia adhere to mammography screening guidelines at the same rate as other same-age women. The study also investigated the validity of the Health Belief (HB) and Stages of Change (SOC) models for breast cancer screening among women with schizophrenia., Methods: Socio-demographic and clinical variables, as well as knowledge, attitudes, and barriers were assessed as a function of stage of change related to breast cancer screening in 46 women with schizophrenia., Results: Women with schizophrenia were statistically less likely to be adherent to the screening recommendations than those without schizophrenia. Some support was found for the validity of the HB and SOC models for breast cancer screening in women with schizophrenia. Women in the Precontemplation stage had significantly higher negative attitude scores compared to Contemplation and Action/Maintenance stages (59.7, 45.7, and 43.2, respectively), and there was a trend for more barriers in the Precontemplation group (4.6, 2.6, 2.7 respectively)., Conclusion: Given the small sample size, further research on the rates of breast cancer screening in women with schizophrenia is warranted. Nonetheless, these data suggest that providers who care for women with schizophrenia may need to make take additional measures to ensure that this population receives appropriate screening so as to not put them at greater risk for a late-stage diagnosis of breast cancer. Furthermore, these pilot data suggest that HB and SOC theory-based interventions may be valid for increasing mammography rates in women with schizophrenia.
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- 2006
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