Publications by authors named "Susan Armstrong"

113 Publications

Meiotic chromosome axis remodelling is critical for meiotic recombination in Brassica rapa.

J Exp Bot 2021 Jan 27. Epub 2021 Jan 27.

Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) OT Gatersleben, Corrensstrasse, Seeland, Germany.

Meiosis generates genetic variation through homologous recombination (HR) that is harnessed during breeding. HR occurs in the context of meiotic chromosome axes and the synaptonemal complex. To study the role of axis remodelling on crossover (CO) formation in a crop species, we characterized mutants of the axis-associated protein ASY1 and the axis-remodelling protein PCH2 in Brassica rapa. asy1 plants form meiotic chromosome axes that fail to synapse. CO formation is almost abolished and residual chiasmata are proportionally enriched in terminal chromosome regions, particularly in the nucleolar organizing region (NOR)-carrying chromosome arm. pch2 plants show impaired ASY1 loading and remodelling consequently achieving only partial synapsis, which leads to reduced CO formation and loss of the obligatory CO. PCH2-independent chiasmata are proportionally enriched towards distal chromosome regions. Similarly, in Arabidopsis pch2 COs are increased towards telomeric regions at the expense of (peri-)centromeric COs compared to WT. Together, in B. rapa axis formation and remodelling are critical for meiotic fidelity including synapsis and CO formation and in asy1 and pch2 CO distributions are altered. While asy1 plants are sterile, pch2 plants are semi-sterile and thus PCH2 could be an interesting target for breeding programs.
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http://dx.doi.org/10.1093/jxb/erab035DOI Listing
January 2021

Biologic subtypes of melanoma predict survival benefit of combination anti-PD1+anti-CTLA4 immune checkpoint inhibitors versus anti-PD1 monotherapy.

J Immunother Cancer 2021 Jan;9(1)

Department of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada

Purpose: Anti-programmed cell death protein 1 (PD1)±anti-cytotoxic T-lymphocyte associated protein 4 (CTLA4) immune checkpoint inhibitors (ICIs) are standard therapeutic options for metastatic melanoma. We assessed whether biologic subtype according to primary tumor type or genomic subtype can function as predictive biomarkers for anti-PD1±anti-CTLA4 ICI in patients with advanced melanoma.

Methods: We performed a single-center retrospective cohort analysis of patients who received anti-PD1±anti-CTLA4 ICI for advanced melanoma between 2012 and 2019. Primary tumor type, and mutation status, and other covariates were abstracted from chart review. Log-rank tests and multivariable Cox regression models were used to assess differences in clinical progression-free (cPFS) and overall survival (OS).

Results: We identified 230 patients who received 249 lines of anti-PD1±anti-CTLA4 ICI for unresectable or metastatic disease. Of these patients, 74% were cutaneous, 11% mucosal, 8% unknown primary and 7% acral. and mutations were identified in 35% and 28% of patients, respectively. In multivariable analyses of the entire cohort, acral or mucosal primary tumor type, >3 metastatic sites, elevated LDH were predictive of shorter cPFS and OS. Combination ICI therapy was associated with longer cPFS (HR 0.57, 95% CI 0.38 to 0.86, p=0.007) and OS (HR 0.42, 95% CI 0.28 to 0.65, p<0.001). Combination ICI was significantly associated with longer OS in unknown primary and mucosal melanoma. There was a non-significant trend toward longer OS with anti-PD1+anti-CTLA4 in cutaneous melanoma, but not in acral melanoma. In multivariable analyses, combination ICI was associated with longer OS in (HR 0.24, 95% CI 0.10 to 0.62, p=0.003, n=69) and V600E/K (HR 0.47, 95% CI 0.24 to 0.90, p=0.024, n=86) mutant melanoma but not wild-type (n=94) melanoma.

Conclusions: In our cohort, primary melanoma tumor type and genomic subtype were independent predictive markers of cPFS and OS for patients with metastatic melanoma receiving anti-PD1 ICI. Primary tumor type and genomic subtype-including NRAS-should be further evaluated in prospective clinical trials to determine their value as predictive markers. Biologic subtypes may facilitate clinical decision-making when recommending combination ICI treatment (anti-PD1±anti-CTLA4) versus anti-PD1 alone for patients with metastatic melanoma.
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http://dx.doi.org/10.1136/jitc-2020-001642DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7831745PMC
January 2021

A major quantitative trait locus on chromosome A9, BnaPh1, controls homoeologous recombination in Brassica napus.

New Phytol 2021 Mar 3;229(6):3281-3293. Epub 2020 Nov 3.

Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada.

Ensuring faithful homologous recombination in allopolyploids is essential to maintain optimal fertility of the species. Variation in the ability to control aberrant pairing between homoeologous chromosomes in Brassica napus has been identified. The current study exploited the extremes of such variation to identify genetic factors that differentiate newly resynthesised B. napus, which is inherently unstable, and established B. napus, which has adapted to largely control homoeologous recombination. A segregating B. napus mapping population was analysed utilising both cytogenetic observations and high-throughput genotyping to quantify the levels of homoeologous recombination. Three quantitative trait loci (QTL) were identified that contributed to the control of homoeologous recombination in the important oilseed crop B. napus. One major QTL on BnaA9 contributed between 32 and 58% of the observed variation. This study is the first to assess homoeologous recombination and map associated QTLs resulting from deviations in normal pairing in allotetraploid B. napus. The identified QTL regions suggest candidate meiotic genes that could be manipulated in order to control this important trait and further allow the development of molecular markers to utilise this trait to exploit homoeologous recombination in a crop.
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http://dx.doi.org/10.1111/nph.16986DOI Listing
March 2021

Stuart Warren (24 Dec 1938-22 Mar 2020).

Org Biomol Chem 2020 Sep;18(37):7236-7237

School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.

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http://dx.doi.org/10.1039/d0ob90121kDOI Listing
September 2020

Curriculum framework for advanced practice nursing in sub-Saharan Africa: a multimethod study.

BMJ Open 2020 06 17;10(6):e035580. Epub 2020 Jun 17.

Department of Nursing Education, School of Therapeutic Sciences, University of the Witwatersrand Faculty of Health Sciences, Johannesburg, Gauteng, South Africa.

Objectives: The implementation of advanced practice nursing (APN) programmes in sub-Saharan Africa (SSA) has been difficult due to lack of SSA-specific curriculum frameworks or benchmarks to guide institutions in developing and implementing APN programmes. A few APN programmes in SSA were benchmarked on western philosophy and materials, making local ownership and sustainability challenging. This paper presents an SSA-specific concept-based APN (Child Health Nurse Practitioner, CHNP) curriculum framework developed to guide institutions in developing relevant and responsive APN curricula in order to qualify CHNP and contribute to a decreased incidence of preventable deaths of children in the SSA region.

Design: A sequential multimethod study design consisting of a scoping review, Delphi study, development of a framework by a curriculum team, and evaluation of the curriculum framework by faculty from 15 universities in SSA.

Setting: This study included universities from East, West, Central and Southern Africa.

Participants: The study included international multidisciplinary health professionals and curriculum development experts from 15 universities in 10 SSA countries.

Results: A concept-based Advanced CHNP curriculum framework was developed. The faculty who evaluated the curriculum framework for applicability within their institutions and the SSA context unanimously stated that the framework is detailed, evidenced-based and could be adapted for other APN specialty areas.

Conclusion: The Child Health Nurse Practitioner curriculum framework is comprehensive, context-specific and has the potential to respond to the special child healthcare needs of SSA. It is adaptable for other APN specialty programmes in SSA. Nursing leaders should lobby for funding and advocate for the introduction of the CHNP programme as a collaborative process between government, clinical services, communities and educational institutions.
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http://dx.doi.org/10.1136/bmjopen-2019-035580DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7304806PMC
June 2020

Do These Genes Make My Heart Look Fat? Why Molecular Changes Matter in Congenital Heart Disease.

Can J Cardiol 2020 Jul 17;36(7):997-999. Epub 2020 May 17.

Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; Laboratory Medicine Program, University Health Network, Toronto, Ontario, Canada. Electronic address:

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http://dx.doi.org/10.1016/j.cjca.2020.05.020DOI Listing
July 2020

What's new in fibroblastic tumors?

Virchows Arch 2020 Jan 11;476(1):41-55. Epub 2019 Dec 11.

Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.

Over the last 10 years, a number of advances have been made in our understanding of fibroblastic and myofibroblastic tumors. The rapidly evolving field of molecular diagnostics has resulted in the recognition of new entities and better understanding of tumor pathogenesis, while careful clinicopathologic correlative analyses have led to improvements in modeling tumor behavior. This review will discuss new and emerging entities in fibroblastic neoplasia and provide updates on the pathogenesis, diagnosis, and prognostication of these diverse and challenging tumors.
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http://dx.doi.org/10.1007/s00428-019-02682-xDOI Listing
January 2020

Field cress genome mapping: Integrating linkage and comparative maps with cytogenetic analysis for rDNA carrying chromosomes.

Sci Rep 2019 11 19;9(1):17028. Epub 2019 Nov 19.

Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 7023, SE 75007, Uppsala, Sweden.

Field cress (Lepidium campestre L.), despite its potential as a sustainable alternative oilseed plant, has been underutilized, and no prior attempts to characterize the genome at the genetic or molecular cytogenetic level have been conducted. Genetic maps are the foundation for anchoring and orienting annotated genome assemblies and positional cloning of candidate genes. Our principal goal was to construct a genetic map using integrated approaches of genetic, comparative and cytogenetic map analyses. In total, 503 F interspecific hybrid individuals were genotyped using 7,624 single nucleotide polymorphism markers. Comparative analysis demonstrated that ~57% of the sequenced loci in L. campestre were congruent with Arabidopsis thaliana (L.) genome and suggested a novel karyotype, which predates the ancestral crucifer karyotype. Aceto-orcein chromosome staining and fluorescence in situ hybridization (FISH) analyses confirmed that L. campestre, L. heterophyllum Benth. and their hybrids had a chromosome number of 2n = 2x = 16. Flow cytometric analysis revealed that both species possess 2C roughly 0.4 picogram DNA. Integrating linkage and comparative maps with cytogenetic map analyses assigned two linkage groups to their particular chromosomes. Future work could incorporate FISH utilizing A. thaliana mapped BAC clones to allow the chromosomes of field cress to be identified reliably.
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http://dx.doi.org/10.1038/s41598-019-53320-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6863836PMC
November 2019

The essence, opportunities and threats to Advanced Practice Nursing in Sub-Saharan Africa: A scoping review.

Heliyon 2019 Oct 4;5(10):e02531. Epub 2019 Oct 4.

Department of Nursing Education, School of Therapeutic Sciences, University of Witwatersrand, South Africa.

Background: The conditions that stimulated the implementation of Advanced Practice Nursing programmes all over the world have long been ignored in sub-Saharan Africa.

Objective: This study sought to explore the essence, opportunities and threats to the implementation of an Advanced Practice Nursing (Child Health Nurse Practitioner) programmes in sub-Saharan Africa.

Methods: A scoping review was conducted and findings reviewed by a multinational multidisciplinary health experts' team through a Delphi study.

Results: Children are the majority of the 70-90% of the sub-Saharan African population who reside in the rural areas where access to timely, quality and cost-effective healthcare is poor. The Child Health Nurse Practitioner programme offers an opportunity to provide quality, timely and cost-effective healthcare to sub-Saharan Africa children. Limited resources, opposition from the medical profession, poor nursing governance and lack of context-specific Advanced Practice Nursing benchmark programmes constitute threats to the programme.

Conclusion: The sub-Saharan Africa context provides opportunities that the nursing profession can harness to surmount such threats. Nursing governance structures, however, need to advocate for government and other stakeholders' support for the Child Health Nursing Practitioner programme.
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http://dx.doi.org/10.1016/j.heliyon.2019.e02531DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6812225PMC
October 2019

Using Genome In Situ Hybridization (GISH) to Distinguish the Constituent Genomes of Brassica nigra and B. rapa in the Hybrid B. juncea.

Methods Mol Biol 2020 ;2061:69-78

School of Biosciences, University of Birmingham, Birmingham, UK.

The genome in situ hybridization (GISH) technique has become important for deciphering the organization of the constituent genomes in the allopolyploid plants that comprise many of the crop species. This technique comprises using the nuclear DNA from the constituent genomes as probes that have been labeled separately with different nucleotides that can be identified by using secondary antibodies. The Brassica family includes a range of mustard species with diverse phytochemical and morphological profile, hence making it an important plant family in agriculture. Meiosis is a specialized cellular division which brings the homologous chromosomes together and creates recombinants via pairing and synapsis during its early phase. Transfer of the genetic material within homoelog pairs creates novelty in subsequent generations which hold promise for improving the agriculture sector. This chapter is concerned with developing a GISH technique that discriminates between the constituent genomes in the allopolyploid B. juncea, in order to study meiosis.
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http://dx.doi.org/10.1007/978-1-4939-9818-0_7DOI Listing
December 2020

A multi-faceted community intervention is associated with knowledge and standards of workplace mental health: the Superior Mental Wellness @ Work study.

BMC Public Health 2019 May 24;19(1):638. Epub 2019 May 24.

Thunder Bay District Health Unit, Thunder Bay, Ontario, Canada.

Background: Poor psychosocial work environments, such as those with low psychological support and high demands, can be harmful to the mental health of workers. In Canada, the National Standard for Psychological Health and Safety in the Workplace (the Standard) provides a comprehensive framework for organizations to identify hazards that may contribute to the psychological harm of employees. This study examines the association between a multi-faceted community intervention, the Superior Mental Wellness @ Work program designed to increase awareness of mental health and the National Standard, and outcomes assessing increased awareness and response to the Standard. These outcomes included the 1) prioritization of workplace mental health; 2) familiarity with the Standard; and 3) knowledge of mental health.

Methods: A quasi-experimental design was used to assess the associations of interest. Surveys were sent to two random samples of employer representatives pre-and post-intervention. Intervention participants were also compared to non-participants at the post-intervention stage. T-tests and chi-square tests were used to compare differences between pre- and post-intervention outcomes and also between intervention participants and non-participants identified at the post-intervention survey.

Results: The multi-faceted community intervention was associated with increased familiarity of the Standard, and increased knowledge of mental health challenges, mental health promotion, and existing resources at a community-level. When comparing those companies who participated in the intervention versus those who did not, participants were more likely to prioritize mental health in the workplace. Participants reported a greater need for support to address workplace mental health, poorer perceived mental health of employees, and greater stigma than non-participants. However, participants were more likely to be familiar with the Standard, have an action plan to implement the Standard, and be prepared to champion mental health in the workplace. Participants also had greater knowledge of workplace mental health in general compared to non-participants.

Conclusions: The multi-faceted community intervention, the Superior Mental Wellness @ Work project, was associated with increased familiarity of the Standard, and increased knowledge of mental health challenges, mental health promotion, and existing resources at a community-level. Such a multi-faceted intervention has the capacity to improve mental health literacy and awareness of the Standard.
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http://dx.doi.org/10.1186/s12889-019-6976-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6534893PMC
May 2019

The State of Nursing Research in Ghana: An Integrative Literature Review.

SAGE Open Nurs 2018 Jan-Dec;4:2377960818783820. Epub 2018 Nov 18.

Centre for Health Policy, School of Public Health, University of Witwatersrand, Johannesburg, South Africa.

Introduction: For nursing practice to be responsive to the needs of patients, it must be driven by contextual research evidence. To guide institutional and national nursing research policy, there is need to determine the quantity and quality of nursing research in Ghana.

Purpose: The purpose of this integrative literature review was to quantify, critically evaluate, and describe nursing research publication in Ghana from January 2007 to December 2016 with regard to the country's research capacity to sustain evidence-based practice.

Results: Sixty (60) out of 749 articles identified from EBSCOhost, ProQuest, PubMed, Science Direct, Scopus, Wiley Online Library, and Google Scholar using three keywords (nursing, health, and Ghana) were included. A total of 60,778 human subjects were used in these studies. There were more quantitative (28) studies than qualitative (23) studies. These studies recorded 219 authors from 120 institutions, 55 of which were outside Ghana. Forty-five percent of the articles were published in journals with impact factor. There was a steady increase in publication in Ghana over the decade. A majority of the studies published in education were in curriculum implementation and evaluation.

Conclusions: The increasing number of peer-reviewed nursing research publications in Ghana and the curriculum implementation and evaluation in Ghana signified an increasing capacity of the country to implement and sustain evidence-based practice.

Recommendations: It is recommended that regular research be conducted to evaluate the responsiveness to old and new nursing programs in Ghana.
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http://dx.doi.org/10.1177/2377960818783820DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7774359PMC
November 2018

Detecting Homoeologous Recombination Events in Cultivated Using a Genome-Wide SNP Array.

G3 (Bethesda) 2018 07 31;8(8):2673-2683. Epub 2018 Jul 31.

Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada

The heavy selection pressure due to intensive breeding of has created a narrow gene pool, limiting the ability to produce improved varieties through crosses between cultivars. One mechanism that has contributed to the adaptation of important agronomic traits in the allotetraploid has been chromosomal rearrangements resulting from homoeologous recombination between the constituent A and C diploid genomes. Determining the rate and distribution of such events in natural will assist efforts to understand and potentially manipulate this phenomenon. The Brassica high-density 60K SNP array, which provides genome-wide coverage for assessment of recombination events, was used to assay 254 individuals derived from 11 diverse cultivated spring type These analyses identified reciprocal allele gain and loss between the A and C genomes and allowed visualization of homoeologous recombination events across the genome. The events ranged from loss/gain of 0.09 Mb to entire chromosomes, with almost 5% aneuploidy observed across all gametes. There was a bias toward sub-telomeric exchanges leading to genome homogenization at chromosome termini. The A genome replaced the C genome in 66% of events, and also featured more dominantly in gain of whole chromosomes. These analyses indicate homoeologous recombination is a continuous source of variation in established and the rate of observed events appears to vary with genetic background. The Brassica 60K SNP array will be a useful tool in further study and manipulation of this phenomenon.
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http://dx.doi.org/10.1534/g3.118.200118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6071606PMC
July 2018

Is Excess Alcohol Consumption an Unrecognized Factor Contributing to Falls?

Geriatr Orthop Surg Rehabil 2018 29;9:2151459318760346. Epub 2018 Mar 29.

Templar Day Hospital, St John's Hospital, Howden, Livingston, United Kingdom.

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http://dx.doi.org/10.1177/2151459318760346DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5881968PMC
March 2018

Affinity proteomics reveals extensive phosphorylation of the Brassica chromosome axis protein ASY1 and a network of associated proteins at prophase I of meiosis.

Plant J 2018 Jan 2;93(1):17-33. Epub 2017 Dec 2.

School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.

During meiosis, the formation of crossovers (COs) generates genetic variation and provides physical links that are essential for accurate chromosome segregation. COs occur in the context of a proteinaceous chromosome axis. The transcriptomes and proteomes of anthers and meiocytes comprise several thousand genes and proteins, but because of the level of complexity relatively few have been functionally characterized. Our understanding of the physical and functional interactions between meiotic proteins is also limited. Here we use affinity proteomics to analyse the proteins that are associated with the meiotic chromosome axis protein, ASY1, in Brassica oleracea anthers and meiocytes. We show that during prophase I ASY1 and its interacting partner, ASY3, are extensively phosphorylated, and we precisely assign phosphorylation sites. We identify 589 proteins that co-immunoprecipitate with ASY1. These correspond to 492 Arabidopsis orthologues, over 90% of which form a coherent protein-protein interaction (PPI) network containing known and candidate meiotic proteins, including proteins more usually associated with other cellular processes such as DNA replication and proteolysis. Mutant analysis confirms that affinity proteomics is a viable strategy for revealing previously unknown meiotic proteins, and we show how the PPI network can be used to prioritise candidates for analysis. Finally, we identify another axis-associated protein with a role in meiotic recombination. Data are available via ProteomeXchange with identifier PXD006042.
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http://dx.doi.org/10.1111/tpj.13752DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5767750PMC
January 2018

Through the eyes of the student: Best practices in clinical facilitation.

Curationis 2017 Aug 28;40(1):e1-e8. Epub 2017 Aug 28.

Department of Nursing Education, University of the Witwatersrand.

Background: Clinical facilitation is an essential part of the undergraduate nursing curriculum. A number of studies address the issue of clinical facilitation in South Africa, but there remains a lack of knowledge and understanding regarding what students perceive as best practice in clinical facilitation of their learning.

Objective: To determine what type of clinical facilitation undergraduate students believe should be offered by clinical facilitators (nurse educators, professional nurses and clinical preceptors) in the clinical area in order to best facilitate their learning.

Method: A qualitative, exploratory and descriptive study was conducted. Purposive sampling was performed to select nursing students from the second, third and fourth year of studies from a selected nursing education institution in Johannesburg. The sampling resulted in one focus group for each level of nursing, namely second, third and fourth year nursing students. Interviews were digitally recorded and transcribed verbatim, thematic data analysis was used and trustworthiness was ensured by applying credibility, dependability, confirmability and transferability.

Main Findings: The data revealed that participants differentiated between best practices in clinical facilitation in the clinical skills laboratory and clinical learning environment. In the clinical skills laboratory, pre-contact preparation, demonstration technique and optimising group learning were identified as best practices. In the clinical learning environment, a need for standardisation of procedures in simulation and practice, the allocation and support for students also emerged.

Conclusion: There is a need for all nurses involved in undergraduate nursing education to reflect on how they approach clinical facilitation, in both clinical skills laboratory and clinical learning environment. There is also a need to improve consistency in clinical practices between the nursing education institution and the clinical learning environment so as to support students' adaptation to clinical practice.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6091592PMC
http://dx.doi.org/10.4102/curationis.v40i1.1787DOI Listing
August 2017

Development, Sensibility, and Validity of a Systemic Autoimmune Rheumatic Disease Case Ascertainment Tool.

J Rheumatol 2017 01 1;44(1):18-23. Epub 2016 Nov 1.

From the Toronto Scleroderma Program, Division of Rheumatology, Department of Medicine, Toronto Western and Mount Sinai Hospitals; Division of Genetics and Development, and Health Care and Outcomes Research, Toronto Western Research Institute, University Health Network; Arthritis Centre of Excellence, Division of Rheumatology, Departments of Medicine and Immunology, University Health Network; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.

Objective: Case ascertainment through self-report is a convenient but often inaccurate method to collect information. The purposes of this study were to develop, assess the sensibility, and validate a tool to identify cases of systemic autoimmune rheumatic diseases (SARD) in the outpatient setting.

Methods: The SARD tool was administered to subjects sampled from specialty clinics. Determinants of sensibility - comprehensibility, feasibility, validity, and acceptability - were evaluated using a numeric rating scale from 1-7. Comprehensibility was evaluated using the Flesch Reading Ease and the Flesch-Kincaid Grade Level. Self-reported diagnoses were validated against medical records using Cohen's κ statistic.

Results: There were 141 participants [systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis, Sjögren syndrome (SS), inflammatory myositis (polymyositis/dermatomyositis; PM/DM), and controls] who completed the questionnaire. The Flesch Reading Ease score was 77.1 and the Flesch-Kincaid Grade Level was 4.4. Respondents endorsed (mean ± SD) comprehensibility (6.12 ± 0.92), feasibility (5.94 ± 0.81), validity (5.35 ± 1.10), and acceptability (3.10 ± 2.03). The SARD tool had a sensitivity of 0.91 (95% CI 0.88-0.94) and a specificity of 0.99 (95% CI 0.96-1.00). The agreement between the SARD tool and medical record was κ = 0.82 (95% CI 0.77-0.88). Subgroup analysis by SARD found κ coefficients for SLE to be κ = 0.88 (95% CI 0.79-0.97), SSc κ = 1.0 (95% CI 1.0-1.0), PM/DM κ = 0.72 (95% CI 0.49-0.95), and SS κ = 0.85 (95% CI 0.71-0.99). The screening questions had sensitivity ranging from 0.96 to 1.0 and specificity ranging from 0.88 to 1.0.

Conclusion: This SARD case ascertainment tool has demonstrable sensibility and validity. The use of both screening and confirmatory questions confers added accuracy.
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http://dx.doi.org/10.3899/jrheum.160327DOI Listing
January 2017

A spontaneous mutation in MutL-Homolog 3 (HvMLH3) affects synapsis and crossover resolution in the barley desynaptic mutant des10.

New Phytol 2016 Nov 8;212(3):693-707. Epub 2016 Jul 8.

Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK.

Although meiosis is evolutionarily conserved, many of the underlying mechanisms show species-specific differences. These are poorly understood in large genome plant species such as barley (Hordeum vulgare) where meiotic recombination is very heavily skewed to the ends of chromosomes. The characterization of mutant lines can help elucidate how recombination is controlled. We used a combination of genetic segregation analysis, cytogenetics, immunocytology and 3D imaging to genetically map and characterize the barley meiotic mutant DESYNAPTIC 10 (des10). We identified a spontaneous exonic deletion in the orthologue of MutL-Homolog 3 (HvMlh3) as the causal lesion. Compared with wild-type, des10 mutants exhibit reduced recombination and fewer chiasmata, resulting in the loss of obligate crossovers and leading to chromosome mis-segregation. Using 3D structured illumination microscopy (3D-SIM), we observed that normal synapsis progression was also disrupted in des10, a phenotype that was not evident with standard confocal microscopy and that has not been reported with Mlh3 knockout mutants in Arabidopsis. Our data provide new insights on the interplay between synapsis and recombination in barley and highlight the need for detailed studies of meiosis in nonmodel species. This study also confirms the importance of early stages of prophase I for the control of recombination in large genome cereals.
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http://dx.doi.org/10.1111/nph.14061DOI Listing
November 2016

Integration of Th17- and Lymphotoxin-Derived Signals Initiates Meningeal-Resident Stromal Cell Remodeling to Propagate Neuroinflammation.

Immunity 2015 Dec;43(6):1160-73

Department of Immunology, University of Toronto, Toronto, ON M5S 1A8, Canada. Electronic address:

Tertiary lymphoid tissues (TLTs) have been observed in the meninges of multiple sclerosis (MS) patients, but the stromal cells and molecular signals that support TLTs remain unclear. Here, we show that T helper 17 (Th17) cells induced robust TLTs within the brain meninges that were associated with local demyelination during experimental autoimmune encephalitis (EAE). Th17-cell-induced TLTs were underpinned by a network of stromal cells producing extracellular matrix proteins and chemokines, enabling leukocytes to reside within, rather than simply transit through, the meninges. Within the CNS, interactions between lymphotoxin αβ (LTαβ) on Th17 cells and LTβR on meningeal radio-resistant cells were necessary for the propagation of de novo interleukin-17 responses, and activated T cells from MS patients expressed elevated levels of LTβR ligands. Therefore, input from both Th17 cells and the lymphotoxin pathway induce the formation of an immune-competent stromal cell niche in the meninges.
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http://dx.doi.org/10.1016/j.immuni.2015.11.010DOI Listing
December 2015

Influenza Virus Infection Induces Platelet-Endothelial Adhesion Which Contributes to Lung Injury.

J Virol 2016 02 4;90(4):1812-23. Epub 2015 Dec 4.

Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute of St. Michael's Hospital, Toronto, Canada Institute of Medical Science, University of Toronto, Toronto, Canada Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada Division of Respirology and Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada

Lung injury after influenza infection is characterized by increased permeability of the lung microvasculature, culminating in acute respiratory failure. Platelets interact with activated endothelial cells and have been implicated in the pathogenesis of some forms of acute lung injury. Autopsy studies have revealed pulmonary microthrombi after influenza infection, and epidemiological studies suggest that influenza vaccination is protective against pulmonary thromboembolism; however, the effect of influenza infection on platelet-endothelial interactions is unclear. We demonstrate that endothelial infection with both laboratory and clinical strains of influenza virus increased the adhesion of human platelets to primary human lung microvascular endothelial cells. Platelets adhered to infected cells as well as to neighboring cells, suggesting a paracrine effect. Influenza infection caused the upregulation of von Willebrand factor and ICAM-1, but blocking these receptors did not prevent platelet-endothelial adhesion. Instead, platelet adhesion was inhibited by both RGDS peptide and a blocking antibody to platelet integrin α5β1, implicating endothelial fibronectin. Concordantly, lung histology from infected mice revealed viral dose-dependent colocalization of viral nucleoprotein and the endothelial marker PECAM-1, while platelet adhesion and fibronectin deposition also were observed in the lungs of influenza-infected mice. Inhibition of platelets using acetylsalicylic acid significantly improved survival, a finding confirmed using a second antiplatelet agent. Thus, influenza infection induces platelet-lung endothelial adhesion via fibronectin, contributing to mortality from acute lung injury. The inhibition of platelets may constitute a practical adjunctive strategy to the treatment of severe infections with influenza.IMPORTANCE There is growing appreciation of the involvement of the lung endothelium in the pathogenesis of severe infections with influenza virus. We have recently shown that the virus can infect human lung endothelial cells, but the functional consequences of this infection are unknown (S. M. Armstrong, C. Wang, J. Tigdi, X. Si, C. Dumpit, S. Charles, A. Gamage, T. J. Moraes, and W. L. Lee, PLoS One 7:e47323, 2012, http://dx.doi.org/10.1371/journal.pone.0047323). Here, we show that this infection causes platelets to adhere to the lung endothelium. Importantly, blocking platelets using two distinct antiplatelet drugs improved survival in a mouse model of severe influenza infection. Thus, platelet inhibition may constitute a novel therapeutic strategy to improve the host response to severe infections with influenza.
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http://dx.doi.org/10.1128/JVI.02599-15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4733979PMC
February 2016

A novel assay uncovers an unexpected role for SR-BI in LDL transcytosis.

Cardiovasc Res 2015 Nov 2;108(2):268-77. Epub 2015 Sep 2.

Keenan Research Centre, St Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B 1W8 Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada Interdepartmental Division of Critical Care Medicine and the Department of Medicine, University of Toronto, Toronto, ON, Canada

Aims: Retention of low-density lipoprotein (LDL) cholesterol beneath the arterial endothelium initiates an inflammatory response culminating in atherosclerosis. Since the overlying endothelium is healthy and intact early on, it is likely that LDL passes through endothelial cells by transcytosis. However, technical challenges have made confirming this notion and elucidating the mechanisms of transcytosis difficult. We developed a novel assay for measuring LDL transcytosis in real time across coronary endothelial cell monolayers; we used this approach to identify the receptor involved.

Methods And Results: Murine aortas were perfused ex vivo with LDL and dextran of a smaller molecular radius. LDL (but not dextran) accumulated under the endothelium, indicating that LDL transcytosis occurs in intact vessels. We then confirmed that LDL transcytosis occurs in vitro using human coronary artery endothelial cells. An assay was developed to quantify transcytosis of DiI-LDL in real time using total internal reflection fluorescence microscopy. DiI-LDL transcytosis was inhibited by excess unlabelled LDL, while degradation of the LDL receptor by PCSK9 had no effect. Instead, LDL colocalized partially with the scavenger receptor SR-BI and overexpression of SR-BI increased LDL transcytosis; knockdown by siRNA significantly reduced it. Excess HDL, the canonical SR-BI ligand, significantly decreased LDL transcytosis. Aortas from SR-BI-deficient mice were perfused ex vivo with LDL and accumulated significantly less sub-endothelial LDL compared with wild-type littermates.

Conclusion: We developed an assay to quantify LDL transcytosis across endothelial cells and discovered an unexpected role for SR-BI. Elucidating the mechanisms of LDL transcytosis may identify novel targets for the prevention or therapy of atherosclerosis.
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http://dx.doi.org/10.1093/cvr/cvv218DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4614686PMC
November 2015

Arabidopsis PCH2 Mediates Meiotic Chromosome Remodeling and Maturation of Crossovers.

PLoS Genet 2015 Jul 16;11(7):e1005372. Epub 2015 Jul 16.

School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.

Meiotic chromosomes are organized into linear looped chromatin arrays by a protein axis localized along the loop-bases. Programmed remodelling of the axis occurs during prophase I of meiosis. Structured illumination microscopy (SIM) has revealed dynamic changes in the chromosome axis in Arabidopsis thaliana and Brassica oleracea. We show that the axis associated protein ASY1 is depleted during zygotene concomitant with synaptonemal complex (SC) formation. Study of an Atpch2 mutant demonstrates this requires the conserved AAA+ ATPase, PCH2, which localizes to the sites of axis remodelling. Loss of PCH2 leads to a failure to deplete ASY1 from the axes and compromizes SC polymerisation. Immunolocalization of recombination proteins in Atpch2 indicates that recombination initiation and CO designation during early prophase I occur normally. Evidence suggests that CO interference is initially functional in the mutant but there is a defect in CO maturation following designation. This leads to a reduction in COs and a failure to form COs between some homologous chromosome pairs leading to univalent chromosomes at metaphase I. Genetic analysis reveals that CO distribution is also affected in some chromosome regions. Together these data indicate that the axis remodelling defect in Atpch2 disrupts normal patterned formation of COs.
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http://dx.doi.org/10.1371/journal.pgen.1005372DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4504720PMC
July 2015

The Tie2-agonist Vasculotide rescues mice from influenza virus infection.

Sci Rep 2015 Jun 5;5:11030. Epub 2015 Jun 5.

1] Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON [2] Department of Laboratory Medicine and Pathobiology, University of Toronto [3] Interdepartmental Division of Critical Care and Department of Medicine, University of Toronto.

Seasonal influenza virus infections cause hundreds of thousands of deaths annually while viral mutation raises the threat of a novel pandemic strain. Antiviral drugs exhibit limited efficacy unless administered early and may induce viral resistance. Thus, targeting the host response directly has been proposed as a novel therapeutic strategy with the added potential benefit of not eliciting viral resistance. Severe influenza virus infections are complicated by respiratory failure due to the development of lung microvascular leak and acute lung injury. We hypothesized that enhancing lung endothelial barrier integrity could improve the outcome. Here we demonstrate that the Tie2-agonist tetrameric peptide Vasculotide improves survival in murine models of severe influenza, even if administered as late as 72 hours after infection; the benefit was observed using three strains of the virus and two strains of mice. The effect required Tie2, was independent of viral replication and did not impair lung neutrophil recruitment. Administration of the drug decreased lung edema, arterial hypoxemia and lung endothelial apoptosis; importantly, Vasculotide is inexpensive to produce, is chemically stable and is unrelated to any Tie2 ligands. Thus, Vasculotide may represent a novel and practical therapy for severe infections with influenza.
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http://dx.doi.org/10.1038/srep11030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4457136PMC
June 2015

Social accountability and nursing education in South Africa.

Glob Health Action 2015 11;8:27879. Epub 2015 May 11.

Centre for Health Policy & Medical Research Council Health Policy Research Group, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa;

Background: There is global emphasis on transforming health workforce education in support of universal health coverage.

Objective: This paper uses a social accountability framework, specifically the World Health Organization's six building blocks for transformative education, to explore key informants' perspectives on nursing education in South Africa.

Methods: Using a snowballing sampling technique, 44 key informants were selected purposively on the basis of their expertise or knowledge of the research area. Semi-structured interviews were conducted with the key informants after informed consent had been obtained. The interviews were analysed using template analysis.

Results: South Africa has strategic plans on human resources for health and nursing education, training, and practice and has a well-established system of regulation and accreditation of nursing education through the South African Nursing Council (SANC). Key informants criticised the following: the lack of national staffing norms; sub-optimal governance by both the SANC and the Department of Health; outdated curricula that are unresponsive to population and health system needs; lack of preparedness of nurse educators; and the unsuitability of the majority of nursing students. These problems are exacerbated by a perceived lack of prioritisation of nursing, resource constraints in both the nursing education institutions and the health training facilities, and general implementation inertia.

Conclusion: Social accountability, which is an essential component of transformative education, necessitates that attention be paid to the issues of governance, responsive curricula, educator preparedness, and appropriate student recruitment and selection.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430686PMC
http://dx.doi.org/10.3402/gha.v8.27879DOI Listing
January 2016

The activities of hospital nursing unit managers and quality of patient care in South African hospitals: a paradox?

Glob Health Action 2015 11;8:26243. Epub 2015 May 11.

Centre for Health Policy & Medical Research Council Health Policy Research Group, School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.

Background: Improving the quality of health care is central to the proposed health care reforms in South Africa. Nursing unit managers play a key role in coordinating patient care activities and in ensuring quality care in hospitals.

Objective: This paper examines whether the activities of nursing unit managers facilitate the provision of quality patient care in South African hospitals.

Methods: During 2011, a cross-sectional, descriptive study was conducted in nine randomly selected hospitals (six public, three private) in two South African provinces. In each hospital, one of each of the medical, surgical, paediatric, and maternity units was selected (n=36). Following informed consent, each unit manager was observed for a period of 2 hours on the survey day and the activities recorded on a minute-by-minute basis. The activities were entered into Microsoft Excel, coded into categories, and analysed according to the time spent on activities in each category. The observation data were complemented by semi-structured interviews with the unit managers who were asked to recall their activities on the day preceding the interview. The interviews were analysed using thematic content analysis.

Results: The study found that nursing unit managers spent 25.8% of their time on direct patient care, 16% on hospital administration, 14% on patient administration, 3.6% on education, 13.4% on support and communication, 3.9% on managing stock and equipment, 11.5% on staff management, and 11.8% on miscellaneous activities. There were also numerous interruptions and distractions. The semi-structured interviews revealed concordance between unit managers' recall of the time spent on patient care, but a marked inflation of their perceived time spent on hospital administration.

Conclusion: The creation of an enabling practice environment, supportive executive management, and continuing professional development are needed to enable nursing managers to lead the provision of consistent and high-quality patient care.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430688PMC
http://dx.doi.org/10.3402/gha.v8.26243DOI Listing
January 2016

Influenza-Induced Priming and Leak of Human Lung Microvascular Endothelium upon Exposure to Staphylococcus aureus.

Am J Respir Cell Mol Biol 2015 Oct;53(4):459-70

1 Keenan Research Centre for Biomedical Science at St. Michael's Hospital, Toronto, Ontario, Canada.

A major cause of death after influenza virus infection is lung injury due to a bacterial superinfection, yet the mechanism is unknown. Death has been attributed to virus-induced immunosuppression and bacterial overgrowth, but this hypothesis is based on data from the preantibiotic era and animal models that omit antimicrobial therapy. Because of diagnostic uncertainty, most patients with influenza receive antibiotics, making bacterial overgrowth unlikely. Respiratory failure after superinfection presents as acute respiratory distress syndrome, a disorder characterized by lung microvascular leak and edema. The objective of this study was to determine whether the influenza virus sensitizes the lung endothelium to leak upon exposure to circulating bacterial-derived molecular patterns from Staphylococcus aureus. In vitro as well as in vivo models of influenza followed by S. aureus superinfection were used. Molecular mechanisms were explored using molecular biology, knockout mice, and human autopsy specimens. Influenza virus infection sensitized human lung endothelium to leak when challenged with S. aureus, even at low doses of influenza and even when the pathogens were given days apart. Influenza virus increased endothelial expression of TNFR1 both in vitro and in intact lungs, a finding corroborated by human autopsy specimens of patients with influenza. Leak was recapitulated with protein A, a TNFR1 ligand, and sequential infection caused protein A-dependent loss of IκB, cleavage of caspases 8 and 3, and lung endothelial apoptosis. Mice infected sequentially with influenza virus and S. aureus developed significantly increased lung edema that was protein A and TNFR1 dependent. Influenza virus primes the lung endothelium to leak, predisposing patients to acute respiratory distress syndrome upon exposure to S. aureus.
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http://dx.doi.org/10.1165/rcmb.2014-0373OCDOI Listing
October 2015

Absence of SUN1 and SUN2 proteins in Arabidopsis thaliana leads to a delay in meiotic progression and defects in synapsis and recombination.

Plant J 2015 Jan;81(2):329-46

Departamento de Genética, Facultad de Biología, Universidad Complutense de Madrid, Madrid, 28040, Spain.

The movement of chromosomes during meiosis involves location of their telomeres at the inner surface of the nuclear envelope. Sad1/UNC-84 (SUN) domain proteins are inner nuclear envelope proteins that are part of complexes linking cytoskeletal elements with the nucleoskeleton, connecting telomeres to the force-generating mechanism in the cytoplasm. These proteins play a conserved role in chromosome dynamics in eukaryotes. Homologues of SUN domain proteins have been identified in several plant species. In Arabidopsis thaliana, two proteins that interact with each other, named AtSUN1 and AtSUN2, have been identified. Immunolocalization using antibodies against AtSUN1 and AtSUN2 proteins revealed that they were associated with the nuclear envelope during meiotic prophase I. Analysis of the double mutant Atsun1-1 Atsun2-2 has revealed severe meiotic defects, namely a delay in the progression of meiosis, absence of full synapsis, the presence of unresolved interlock-like structures, and a reduction in the mean cell chiasma frequency. We propose that in Arabidopsis thaliana, overlapping functions of SUN1 and SUN2 ensure normal meiotic recombination and synapsis.
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http://dx.doi.org/10.1111/tpj.12730DOI Listing
January 2015

The kinesin AtPSS1 promotes synapsis and is required for proper crossover distribution in meiosis.

PLoS Genet 2014 Oct 16;10(10):e1004674. Epub 2014 Oct 16.

The French National Institute for Agricultural Research (INRA), Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, Versailles, France; AgroParisTech, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, Versailles, France.

Meiotic crossovers (COs) shape genetic diversity by mixing homologous chromosomes at each generation. CO distribution is a highly regulated process. CO assurance forces the occurrence of at least one obligatory CO per chromosome pair, CO homeostasis smoothes out the number of COs when faced with variation in precursor number and CO interference keeps multiple COs away from each other along a chromosome. In several organisms, it has been shown that cytoskeleton forces are transduced to the meiotic nucleus via KASH- and SUN-domain proteins, to promote chromosome synapsis and recombination. Here we show that the Arabidopsis kinesin AtPSS1 plays a major role in chromosome synapsis and regulation of CO distribution. In Atpss1 meiotic cells, chromosome axes and DNA double strand breaks (DSBs) appear to form normally but only a variable portion of the genome synapses and is competent for CO formation. Some chromosomes fail to form the obligatory CO, while there is an increased CO density in competent regions. However, the total number of COs per cell is unaffected. We further show that the kinesin motor domain of AtPSS1 is required for its meiotic function, and that AtPSS1 interacts directly with WIP1 and WIP2, two KASH-domain proteins. Finally, meiocytes missing AtPSS1 and/or SUN proteins show similar meiotic defects suggesting that AtPSS1 and SUNs act in the same pathway. This suggests that forces produced by the AtPSS1 kinesin and transduced by WIPs/SUNs, are required to authorize complete synapsis and regulate maturation of recombination intermediates into COs. We suggest that a form of homeostasis applies, which maintains the total number of COs per cell even if only a part of the genome is competent for CO formation.
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http://dx.doi.org/10.1371/journal.pgen.1004674DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4199493PMC
October 2014

The role of post-operative imaging in cochlear implant surgery: a review of 220 adult cases.

Cochlear Implants Int 2014 Sep 28;15(5):264-71. Epub 2014 Mar 28.

Objectives: To determine the incidence of abnormal radiological findings after cochlear implantation and their effect on clinical outcomes.

Methods: Retrospective review of 220 adult cochlear implants. Clinical records and post-operative plain X-rays were reviewed and compared with pre-operative and 6-month post-operative City University of New York (CUNY) speech scores.

Results: There were no cases of extra-cochlear array misplacement. Imaging showed 20 cases of incomplete array insertion (9.2%), 3 cases of kinking of the array (1.4%), 2 cases of tip rollover (0.9%), and 1 case of apparent array fracture (0.5%). Patient management was not altered by abnormal imaging. Patients with abnormal radiological findings had slightly minor improvements (median 39 vs. 56%) in City University of New York (CUNY) speech discrimination scores at 6 months (Mann-Whitney U test, P = 0.043).

Conclusion: All abnormalities on post-operative imaging were minor and did not alter patient management. The future role of post-operative imaging is discussed.
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http://dx.doi.org/10.1179/1754762814Y.0000000071DOI Listing
September 2014

The synaptonemal complex protein ZYP1 is required for imposition of meiotic crossovers in barley.

Plant Cell 2014 Feb 21;26(2):729-40. Epub 2014 Feb 21.

Division of Plant Sciences, College of Life Sciences, University of Dundee at The James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom.

In many cereal crops, meiotic crossovers predominantly occur toward the ends of chromosomes and 30 to 50% of genes rarely recombine. This limits the exploitation of genetic variation by plant breeding. Previous reports demonstrate that chiasma frequency can be manipulated in plants by depletion of the synaptonemal complex protein ZIPPER1 (ZYP1) but conflict as to the direction of change, with fewer chiasmata reported in Arabidopsis thaliana and more crossovers reported for rice (Oryza sativa). Here, we use RNA interference (RNAi) to reduce the amount of ZYP1 in barley (Hordeum vulgare) to only 2 to 17% of normal zygotene levels. In the ZYP1(RNAi) lines, fewer than half of the chromosome pairs formed bivalents at metaphase and many univalents were observed, leading to chromosome nondisjunction and semisterility. The number of chiasmata per cell was reduced from 14 in control plants to three to four in the ZYP1-depleted lines, although the localization of residual chiasmata was not affected. DNA double-strand break formation appeared normal, but the recombination pathway was defective at later stages. A meiotic time course revealed a 12-h delay in prophase I progression to the first labeled tetrads. Barley ZYP1 appears to function similarly to ZIP1/ZYP1 in yeast and Arabidopsis, with an opposite effect on crossover number to ZEP1 in rice, another member of the Poaceae.
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http://dx.doi.org/10.1105/tpc.113.121269DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3967036PMC
February 2014