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1.
Psychol Med ; 54(1): 203-214, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37929303

RESUMO

BACKGROUND: While maternal at-risk drinking is associated with children's emotional and behavioral problems, there is a paucity of research that properly accounts for genetic confounding and gene-environment interplay. Therefore, it remains uncertain what mechanisms underlie these associations. We assess the moderation of associations between maternal at-risk drinking and childhood emotional and behavioral problems by common genetic variants linked to environmental sensitivity (genotype-by-environment [G × E] interaction) while accounting for shared genetic risk between mothers and offspring (GE correlation). METHODS: We use data from 109 727 children born to 90 873 mothers enrolled in the Norwegian Mother, Father, and Child Cohort Study. Women self-reported alcohol consumption and reported emotional and behavioral problems when children were 1.5/3/5 years old. We included child polygenic scores (PGSs) for traits linked to environmental sensitivity as moderators. RESULTS: Associations between maternal drinking and child emotional (ß1 = 0.04 [95% confidence interval (CI) 0.03-0.05]) and behavioral (ß1 = 0.07 [0.06-0.08]) outcomes attenuated after controlling for measured confounders and were almost zero when we accounted for unmeasured confounding (emotional: ß1 = 0.01 [0.00-0.02]; behavioral: ß1 = 0.01 [0.00-0.02]). We observed no moderation of these adjusted exposure effects by any of the PGS. CONCLUSIONS: The lack of strong evidence for G × E interaction may indicate that the mechanism is not implicated in this kind of intergenerational association. It may also reflect insufficient power or the relatively benign nature of the exposure in this sample.


Assuntos
Comportamento Problema , Criança , Humanos , Feminino , Lactente , Comportamento Problema/psicologia , Estudos de Coortes , Emoções , Consumo de Bebidas Alcoólicas/epidemiologia , Mães/psicologia , Genótipo
2.
Blood ; 143(4): 336-341, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-37647641

RESUMO

ABSTRACT: Assessment of measurable residual disease (MRD) by quantitative reverse transcription polymerase chain reaction is strongly prognostic in patients with NPM1-mutated acute myeloid leukemia (AML) treated with intensive chemotherapy; however, there are no data regarding its utility in venetoclax-based nonintensive therapy, despite high efficacy in this genotype. We analyzed the prognostic impact of NPM1 MRD in an international real-world cohort of 76 previously untreated patients with NPM1-mutated AML who achieved complete remission (CR)/CR with incomplete hematological recovery following treatment with venetoclax and hypomethylating agents (HMAs) or low-dose cytarabine (LDAC). A total of 44 patients (58%) achieved bone marrow (BM) MRD negativity, and a further 14 (18%) achieved a reduction of ≥4 log10 from baseline as their best response, with no difference between HMAs and LDAC. The cumulative rates of BM MRD negativity by the end of cycles 2, 4, and 6 were 25%, 47%, and 50%, respectively. Patients achieving BM MRD negativity by the end of cycle 4 had 2-year overall of 84% compared with 46% if MRD was positive. On multivariable analyses, MRD negativity was the strongest prognostic factor. A total of 22 patients electively stopped therapy in BM MRD-negative remission after a median of 8 cycles, with 2-year treatment-free remission of 88%. In patients with NPM1-mutated AML attaining remission with venetoclax combination therapies, NPM1 MRD provides valuable prognostic information.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Leucemia Mieloide Aguda , Nucleofosmina , Sulfonamidas , Humanos , Prognóstico , Mutação , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Citarabina , Neoplasia Residual/genética
4.
J Clin Oncol ; 41(19): 3534-3544, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37126762

RESUMO

PURPOSE: Polycythemia vera (PV) is characterized by JAK/STAT activation, thrombotic/hemorrhagic events, systemic symptoms, and disease transformation. In high-risk PV, ruxolitinib controls blood counts and improves symptoms. PATIENTS AND METHODS: MAJIC-PV is a randomized phase II trial of ruxolitinib versus best available therapy (BAT) in patients resistant/intolerant to hydroxycarbamide (HC-INT/RES). Primary outcome was complete response (CR) within 1 year. Secondary outcomes included duration of response, event-free survival (EFS), symptom, and molecular response. RESULTS: One hundred eighty patients were randomly assigned. CR was achieved in 40 (43%) patients on ruxolitinib versus 23 (26%) on BAT (odds ratio, 2.12; 90% CI, 1.25 to 3.60; P = .02). Duration of CR was superior for ruxolitinib (hazard ratio [HR], 0.38; 95% CI, 0.24 to 0.61; P < .001). Symptom responses were better with ruxolitinib and durable. EFS (major thrombosis, hemorrhage, transformation, and death) was superior for patients attaining CR within 1 year (HR, 0.41; 95% CI, 0.21 to 0.78; P = .01); and those on ruxolitinib (HR, 0.58; 95% CI, 0.35 to 0.94; P = .03). Serial analysis of JAK2V617F variant allele fraction revealed molecular response was more frequent with ruxolitinib and was associated with improved outcomes (progression-free survival [PFS] P = .001, EFS P = .001, overall survival P = .01) and clearance of JAK2V617F stem/progenitor cells. ASXL1 mutations predicted for adverse EFS (HR, 3.02; 95% CI, 1.47 to 6.17; P = .003). The safety profile of ruxolitinib was as previously reported. CONCLUSION: The MAJIC-PV study demonstrates ruxolitinib treatment benefits HC-INT/RES PV patients with superior CR, and EFS as well as molecular response; importantly also demonstrating for the first time, to our knowledge, that molecular response is linked to EFS, PFS, and OS.


Assuntos
Policitemia Vera , Humanos , Policitemia Vera/tratamento farmacológico , Policitemia Vera/genética , Policitemia Vera/complicações , Resultado do Tratamento , Hidroxiureia/efeitos adversos , Nitrilas/uso terapêutico , Hemorragia/complicações , Hemorragia/tratamento farmacológico
5.
Methods Mol Biol ; 2383: 595-616, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34766317

RESUMO

Cell penetrating peptides (CPPs) are short peptides that are able to translocate themselves and their cargo into cells. The progressive and continuous application of CPPs in various fields of basic and applied research shows that they are efficient delivery vectors for an assortment of biomolecules, including nucleic acids and proteins. This feature makes CPPs an excellent tool for modification of plant genomes through transgenesis and genome editing. In this review, we present the progress during the last three decades in application of CPPs for delivery of DNA, RNA, and proteins into plant cells and tissues. Moreover, we highlight the exploiting of CPPs as advantageous and beneficial tool for plant genome editing via delivery of nuclease proteins, and provide a practical example of genome alternation through CPP-delivered nucleases. Finally, the current exploitation of peptides in organelle-specific DNA delivery and modification of organellar genomes is discussed.


Assuntos
Edição de Genes , Peptídeos Penetradores de Células/genética , DNA , Endonucleases , Técnicas de Transferência de Genes , Ácidos Nucleicos , Plantas/genética , Proteínas
6.
Methods Mol Biol ; 2287: 295-312, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34270038

RESUMO

Here, we describe a method of triticale isolated microspore culture for production of doubled haploid plants via androgenesis. We use this method routinely because it is highly efficient and works well on different triticale genotypes. To force microspores into becoming embryogenic, we apply a 21-day cold pretreatment. The shock of cold facilitates redirecting microspores from their predestined pollen developmental program into the androgenesis pathway. Ovaries are included in our culture methods to help with embryogenesis, and the histone deacytelase inhibitor Trichostatin A (TSA) is added to further improve androgenesis and increase our ability to recover green doubled haploid plants.


Assuntos
Gametogênese Vegetal , Técnicas de Cultura de Tecidos/métodos , Triticale/crescimento & desenvolvimento , Meios de Cultura , Haploidia , Pólen/embriologia , Pólen/genética , Pólen/crescimento & desenvolvimento , Triticale/embriologia , Triticale/genética
7.
Methods Mol Biol ; 2072: 165-181, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31541446

RESUMO

Recent advances in genome engineering are revolutionizing crop research and plant breeding. The ability to make specific modifications to a plant's genetic material creates opportunities for rapid development of elite cultivars with desired traits. The plant genome can be altered in several ways, including targeted introduction of nucleotide changes, deleting DNA segments, introducing exogenous DNA fragments and epigenetic modifications. Targeted changes are mediated by sequence specific nucleases (SSNs), such as zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and CRISPR (clustered regularly interspersed short palindromic repeats)-Cas (CRISPR associated protein) systems. Recent advances in engineering chimeric Cas nucleases fused to base editing enzymes permit for even greater precision in base editing and control over gene expression. In addition to gene editing technologies, improvement in delivery systems of exogenous DNA into plant cells have increased the rate of successful gene editing events. Regeneration of fertile plants containing the desired edits remains challenging; however, manipulation of embryogenesis-related genes such as BABY BOOM (BBM) has been shown to facilitate regeneration through tissue culture, often a major hurdle in recalcitrant cultivars. Epigenome reprogramming for improved crop performance is another possibility for future breeders, with recent studies on MutS HOMOLOG 1 (MSH1) demonstrating epigenetic-dependent hybrid vigor in several crops. While these technologies offer plant breeders new tools in creating high yielding, better adapted crop varieties, constantly evolving government policy regarding the cultivation of plants containing transgenes may impede the widespread adoption of some of these techniques. This chapter summarizes advances in genome editing tools and discusses the future of these techniques for crop improvement.


Assuntos
Produtos Agrícolas/genética , Engenharia Genética , Genoma de Planta , Genômica , Melhoramento Vegetal , Sistemas CRISPR-Cas , Epigenômica/métodos , Edição de Genes , Regulação da Expressão Gênica de Plantas , Engenharia Genética/métodos , Genômica/métodos , Melhoramento Vegetal/métodos , Desenvolvimento Vegetal/genética , Plantas Geneticamente Modificadas , Característica Quantitativa Herdável , Nucleases dos Efetores Semelhantes a Ativadores de Transcrição
8.
BMC Plant Biol ; 17(1): 47, 2017 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-28219335

RESUMO

BACKGROUND: Proper regulation of nuclear-encoded, organelle-targeted genes is crucial for plastid and mitochondrial function. Among these genes, MutS Homolog 1 (MSH1) is notable for generating an assortment of mutant phenotypes with varying degrees of penetrance and pleiotropy. Stronger phenotypes have been connected to stress tolerance and epigenetic changes, and in Arabidopsis T-DNA mutants, two generations of homozygosity with the msh1 insertion are required before severe phenotypes begin to emerge. These observations prompted us to examine how msh1 mutants contrast according to generation and phenotype by profiling their respective transcriptomes and small RNA populations. RESULTS: Using RNA-seq, we analyze pathways that are associated with MSH1 loss, including abiotic stresses such as cold response, pathogen defense and immune response, salicylic acid, MAPK signaling, and circadian rhythm. Subtle redox and environment-responsive changes also begin in the first generation, in the absence of strong phenotypes. Using small RNA-seq we further identify miRNA changes, and uncover siRNA trends that indicate modifications at the chromatin organization level. In all cases, the magnitude of changes among protein-coding genes, transposable elements, and small RNAs increases according to generation and phenotypic severity. CONCLUSION: Loss of MSH1 is sufficient to cause large-scale regulatory changes in pathways that have been individually linked to one another, but rarely described all together within a single mutant background. This study enforces the recognition of organelles as critical integrators of both internal and external cues, and highlights the relationship between organelle and nuclear regulation in fundamental aspects of plant development and stress signaling. Our findings also encourage further investigation into potential connections between organelle state and genome regulation vis-á-vis small RNA feedback.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Mitocôndrias/genética , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Proteína MutS de Ligação de DNA com Erro de Pareamento/metabolismo , DNA Bacteriano/genética , Organelas/genética , Organelas/metabolismo , Plastídeos/genética , Plastídeos/metabolismo , Transcriptoma/genética
9.
Mol Plant ; 9(2): 245-260, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26584715

RESUMO

As metabolic centers, plant organelles participate in maintenance, defense, and signaling. MSH1 is a plant-specific protein involved in organellar genome stability in mitochondria and plastids. Plastid depletion of MSH1 causes heritable, non-genetic changes in development and DNA methylation. We investigated the msh1 phenotype using hemi-complementation mutants and transgene-null segregants from RNAi suppression lines to sub-compartmentalize MSH1 effects. We show that MSH1 expression is spatially regulated, specifically localizing to plastids within the epidermis and vascular parenchyma. The protein binds DNA and localizes to plastid and mitochondrial nucleoids, but fractionation and protein-protein interactions data indicate that MSH1 also associates with the thylakoid membrane. Plastid MSH1 depletion results in variegation, abiotic stress tolerance, variable growth rate, and delayed maturity. Depletion from mitochondria results in 7%-10% of plants altered in leaf morphology, heat tolerance, and mitochondrial genome stability. MSH1 does not localize within the nucleus directly, but plastid depletion produces non-genetic changes in flowering time, maturation, and growth rate that are heritable independent of MSH1. MSH1 depletion alters non-photoactive redox behavior in plastids and a sub-set of mitochondrially altered lines. Ectopic expression produces deleterious effects, underlining its strict expression control. Unraveling the complexity of the MSH1 effect offers insight into triggers of plant-specific, transgenerational adaptation behaviors.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteína MutS de Ligação de DNA com Erro de Pareamento/metabolismo , Tilacoides/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , DNA de Plantas/genética , DNA de Plantas/metabolismo , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Plastídeos/genética , Plastídeos/metabolismo , Tilacoides/genética
10.
Nat Commun ; 6: 6386, 2015 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-25722057

RESUMO

Plant phenotypes respond to environmental change, an adaptive capacity that is at least partly transgenerational. However, epigenetic components of this interplay are difficult to measure. Depletion of the nuclear-encoded protein MSH1 causes dramatic and heritable changes in plant development, and here we show that crossing these altered plants with isogenic wild type produces epi-lines with heritable, enhanced growth vigour. Pericentromeric DNA hypermethylation occurs in a subset of msh1 mutants, indicative of heightened transposon repression, while enhanced growth epi-lines show large chromosomal segments of differential CG methylation, reflecting genome-wide reprogramming. When seedlings are treated with 5-azacytidine, root growth of epi-lines is restored to wild-type levels, implicating hypermethylation in enhanced growth. Grafts of wild-type floral stems to mutant rosettes produce progeny with enhanced growth and altered CG methylation strikingly similar to epi-lines, indicating a mobile signal when MSH1 is downregulated, and confirming the programmed nature of methylome and phenotype changes.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Metilação de DNA , Epigênese Genética/genética , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Azacitidina , Sequência de Bases , Cruzamentos Genéticos , Primers do DNA/genética , Epigênese Genética/fisiologia , Biblioteca Gênica , Anotação de Sequência Molecular , Dados de Sequência Molecular , Mutação/genética , Raízes de Plantas/crescimento & desenvolvimento , Polimorfismo de Nucleotídeo Único/genética , Interferência de RNA , Análise de Sequência de DNA
11.
PLoS Pathog ; 10(7): e1004223, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24992661

RESUMO

The basidiomycete smut fungus Ustilago hordei was previously shown to comprise isolates that are avirulent on various barley host cultivars. Through genetic crosses we had revealed that a dominant avirulence locus UhAvr1 which triggers immunity in barley cultivar Hannchen harboring resistance gene Ruh1, resided within an 80-kb region. DNA sequence analysis of this genetically delimited region uncovered the presence of 7 candidate secreted effector proteins. Sequence comparison of their coding sequences among virulent and avirulent parental and field isolates could not distinguish UhAvr1 candidates. Systematic deletion and complementation analyses revealed that UhAvr1 is UHOR_10022 which codes for a small effector protein of 171 amino acids with a predicted 19 amino acid signal peptide. Virulence in the parental isolate is caused by the insertion of a fragment of 5.5 kb with similarity to a common U. hordei transposable element (TE), interrupting the promoter of UhAvr1 and thereby changing expression and hence recognition of UhAVR1p. This rearrangement is likely caused by activities of TEs and variation is seen among isolates. Using GFP-chimeric constructs we show that UhAvr1 is induced only in mated dikaryotic hyphae upon sensing and infecting barley coleoptile cells. When infecting Hannchen, UhAVR1p causes local callose deposition and the production of reactive oxygen species and necrosis indicative of the immune response. UhAvr1 does not contribute significantly to overall virulence. UhAvr1 is located in a cluster of ten effectors with several paralogs and over 50% of TEs. This cluster is syntenous with clusters in closely-related U. maydis and Sporisorium reilianum. In these corn-infecting species, these clusters harbor however more and further diversified homologous effector families but very few TEs. This increased variability may have resulted from past selection pressure by resistance genes since U. maydis is not known to trigger immunity in its corn host.


Assuntos
Proteínas Fúngicas/imunologia , Hordeum/imunologia , Doenças das Plantas/imunologia , Imunidade Vegetal , Ustilago/imunologia , Fatores de Virulência/imunologia , Proteínas Fúngicas/genética , Hordeum/genética , Hordeum/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Ustilago/genética , Ustilago/patogenicidade , Fatores de Virulência/genética , Zea mays/genética , Zea mays/imunologia , Zea mays/microbiologia
12.
Proc Natl Acad Sci U S A ; 111(21): 7582-7, 2014 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-24821765

RESUMO

Endosperm is a filial structure resulting from a second fertilization event in angiosperms. As an absorptive storage organ, endosperm plays an essential role in support of embryo development and seedling germination. The accumulation of carbohydrate and protein storage products in cereal endosperm provides humanity with a major portion of its food, feed, and renewable resources. Little is known regarding the regulatory gene networks controlling endosperm proliferation and differentiation. As a first step toward understanding these networks, we profiled all mRNAs in the maize kernel and endosperm at eight successive stages during the first 12 d after pollination. Analysis of these gene sets identified temporal programs of gene expression, including hundreds of transcription-factor genes. We found a close correlation of the sequentially expressed gene sets with distinct cellular and metabolic programs in distinct compartments of the developing endosperm. The results constitute a preliminary atlas of spatiotemporal patterns of endosperm gene expression in support of future efforts for understanding the underlying mechanisms that control seed yield and quality.


Assuntos
Endosperma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica de Plantas/genética , Zea mays/genética , Biologia Computacional , Perfilação da Expressão Gênica , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA , Fatores de Tempo , Zea mays/metabolismo
13.
Plant Cell ; 25(9): 3212-27, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24058158

RESUMO

In angiosperms, the endosperm provides nutrients for embryogenesis and seed germination and is the primary tissue where gene imprinting occurs. To identify the imprintome of early developing maize (Zea mays) endosperm, we performed high-throughput transcriptome sequencing of whole kernels at 0, 3, and 5 d after pollination (DAP) and endosperms at 7, 10, and 15 DAP, using B73 by Mo17 reciprocal crosses. We observed gradually increased expression of paternal transcripts in 3- and 5-DAP kernels. In 7-DAP endosperm, the majority of the genes tested reached a 2:1 maternal versus paternal ratio, suggesting that paternal genes are nearly fully activated by 7 DAP. A total of 116, 234, and 63 genes exhibiting parent-specific expression were identified at 7, 10, and 15 DAP, respectively. The largest proportion of paternally expressed genes was at 7 DAP, mainly due to the significantly deviated parental allele expression ratio of these genes at this stage, while nearly 80% of the maternally expressed genes (MEGs) were specific to 10 DAP and were primarily attributed to sharply increased expression levels compared with the other stages. Gene ontology enrichment analysis of the imprinted genes suggested that 10-DAP endosperm-specific MEGs are involved in nutrient uptake and allocation and the auxin signaling pathway, coincident with the onset of starch and storage protein accumulation.


Assuntos
Endosperma/genética , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Impressão Genômica/genética , Transcriptoma , Zea mays/genética , Alelos , Sequência de Bases , Diferenciação Celular , Metilação de DNA , Endosperma/crescimento & desenvolvimento , Endosperma/metabolismo , Perfilação da Expressão Gênica , Biblioteca Gênica , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Especificidade de Órgãos , Polinização , Polimorfismo de Nucleotídeo Único , RNA de Plantas/química , RNA de Plantas/genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Análise de Sequência de RNA , Amido/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
14.
Thromb Res ; 131(5): e210-3, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23473642

RESUMO

INTRODUCTION: Fibrinogen deficiency often develops during massive bleeding due to e.g. fluid resuscitation with colloid plasma expanders like hydroxyethyl starch. This study investigates the haemostatic effect of various sources of fibrinogen: fibrinogen concentrates (Haemocomplettan® (FC 1), CSL Behring and Clottagen® (FC 2), LFB Biomedicaments), fresh frozen plasma (FFP), and Cryoprecipitate (CP). METHODS: Whole blood samples provided by healthy individuals (n=8) were diluted 1:1 with HES or 0.9% isotonic saline as control. Various sources of fibrinogen was added to the HES diluted samples in concentrations equivalent to giving a 70 kg male either no correction, 2 grams of FC 1 or FC 2, 4 grams of FC 1 or FC 2, 15 ml/kg of FFP, 2 packs of CP or 4 packs of CP. Haemostatic effect was assessed by thromboelastometry initiated by tissue factor, with maximum clot firmness (MCF) as the primary endpoint. In addition thrombin generation was assessed for each intervention RESULTS: HES dilution reduced MCF significantly more than isotonic saline. High dose FC 1, 2 and CP corrected the MCF so that it did not differ significantly from the isotonic saline dilution group. Thrombin generation following isotonic saline and HES dilution was comparable and not decreased compared to whole blood. Fibrinogen concentrates supplementation did not increase thrombin generation whereas CP and FFP both increased thrombin generation CONCLUSION: Fibrinogen concentrates investigated dose dependently and equally corrected the MCF and caused no increase in thrombin generation. Cryoprecipitate also corrected the MCF, but also increased thrombin generation. FFP failed to improve MCF, but increased thrombin generation.


Assuntos
Afibrinogenemia/terapia , Fibrinogênio/administração & dosagem , Hemodiluição/métodos , Plasma , Hemodiluição/efeitos adversos , Humanos , Masculino , Tromboelastografia/métodos , Trombina/metabolismo
15.
Plant Signal Behav ; 8(4): e23853, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23425853

RESUMO

The availability of three genomes from smut fungi differing in mating, TE load, and genome defense mechanisms, allowed a comparative analyses and a discussion on evolutionary forces shaping them. A complex balance of selective forces seems at play. A bipolar mating system in Ustilago hordei promotes selfing, advantageous for successful niche occupation but favoring accumulation of repetitive DNA, including TEs. TE activity may have caused genome variations necessary for these obligate parasites under high host selection pressures. Higher TE activity is balanced by genome defenses through recombination, RNAi, methylation and RIP mutagenesis. In tetrapolar U. maydis, lacking silencing and possibly methylation mechanisms, reduced inbreeding potential favors removal of repetitive DNA, presumably by its highly-efficient recombination system.


Assuntos
Metilação de DNA , Elementos de DNA Transponíveis , DNA Fúngico , Genoma Fúngico , Interferência de RNA , Recombinação Genética , Ustilago/genética , Mutação , RNA Fúngico , Reprodução
16.
J Clin Virol ; 55(3): 278-81, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22959064

RESUMO

BACKGROUND: Primary BK virus (BKV) infection is probably acquired by the respiratory route in childhood, and latent virus persists principally in the urinary tract. BKV reactivation is implicated in late onset haemorrhagic cystitis (HC) post Haematopoietic Stem Cell Transplant (HSCT). There is emerging evidence that BKV can cause life-threatening pneumonitis in immunocompromised individuals. OBJECTIVES: To describe the first known case of BKV pneumonitis in an adult HSCT recipient. STUDY DESIGN/RESULTS: A 19-year old male underwent an ABO-incompatible, volunteer unrelated donor allogeneic HSCT for high risk AML. The post-transplant period was complicated by moderate-severe cutaneous and gut acute graft-versus-host disease (aGVHD) and severe HC, attributable to BKV. Treatment encompassed intensification of immunosupression for aGVHD and weekly intravenous (IV) cidofovir (2.5mg/Kg) for BK viruria. He was readmitted with presumed septic shock and acute renal failure. After a transient improvement on broad spectrum antibacterials, he suffered significant respiratory deterioration. CT imaging revealed diffuse 'ground-glass' attenuation. Cytopathological assessment of a broncho-alveolar sample (BAL) was consistent with polyomavirus pneumonitis. No other cause was found to account for the respiratory deterioration. He did not respond to therapy and died of multi-organ failure. CONCLUSIONS: BKV is implicated in haemorrhagic cystitis in HSCT recipients but not routinely considered as a cause of pneumonitis. There are just 5 other cases in the literature, including 3 patients with AIDS. BKV should be considered as a possible cause of pneumonitis in HSCT recipients.


Assuntos
Vírus BK/isolamento & purificação , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Pneumonia/diagnóstico , Infecções por Polyomavirus/diagnóstico , Infecções Tumorais por Vírus/diagnóstico , Líquido da Lavagem Broncoalveolar/citologia , Técnicas Citológicas , Humanos , Hospedeiro Imunocomprometido , Masculino , Pneumonia/patologia , Infecções por Polyomavirus/patologia , Transplante , Infecções Tumorais por Vírus/patologia , Adulto Jovem
17.
Plant Cell ; 24(5): 1733-45, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22623492

RESUMO

Ustilago hordei is a biotrophic parasite of barley (Hordeum vulgare). After seedling infection, the fungus persists in the plant until head emergence when fungal spores develop and are released from sori formed at kernel positions. The 26.1-Mb U. hordei genome contains 7113 protein encoding genes with high synteny to the smaller genomes of the related, maize-infecting smut fungi Ustilago maydis and Sporisorium reilianum but has a larger repeat content that affected genome evolution at important loci, including mating-type and effector loci. The U. hordei genome encodes components involved in RNA interference and heterochromatin formation, normally involved in genome defense, that are lacking in the U. maydis genome due to clean excision events. These excision events were possibly a result of former presence of repetitive DNA and of an efficient homologous recombination system in U. maydis. We found evidence of repeat-induced point mutations in the genome of U. hordei, indicating that smut fungi use different strategies to counteract the deleterious effects of repetitive DNA. The complement of U. hordei effector genes is comparable to the other two smuts but reveals differences in family expansion and clustering. The availability of the genome sequence will facilitate the identification of genes responsible for virulence and evolution of smut fungi on their respective hosts.


Assuntos
Elementos de DNA Transponíveis/genética , Hordeum/microbiologia , Ustilago/genética , Zea mays/microbiologia , Genoma Fúngico/genética , Interferência de RNA/fisiologia
18.
Oecologia ; 167(2): 315-23, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21472417

RESUMO

Conditions experienced in early life have been shown to affect the development or programming of physiological processes. While animals may recover from earlier periods of adversity, this process can carry long-term costs. Such long-term effects are likely to be most evident when individuals are placed in demanding situations that require high performance. Escape flight speed in passerine birds is crucial to predator evasion and requires very rapid take-off. Here, we examine whether the ability to maintain escape flight performance during the immediate post-breeding period is influenced by conditions in early life. We manipulated the early life conditions experienced by zebra finches (Taeniopygia guttata) by rearing them on either low or high quality food through the growth period, or by changing conditions halfway through the nestling period, moving from high to low or vice versa. While there was no difference amongst the treatment groups in body size attained by adulthood, amongst the birds that experienced low quality food, the body size of those that were switched to a high quality diet halfway through the nestling growth period recovered faster than those that had low quality food until fledging. We found no differences amongst the dietary groups in flight performance at adulthood prior to breeding, and all groups showed a decline in average escape flight performance over the breeding period. However, the magnitude of the post-breeding decline in flight performance for a given level of reproductive output was significantly greater for those females that had experienced a switch from a low to a high quality diet during the nestling phase. These results suggest that this diet-induced rapid recovery of body size, which may have immediate competitive advantages, nonetheless carries locomotory costs in later life manifest in the capacity to sustain the high performance escape response during the post-reproductive recovery phase.


Assuntos
Voo Animal , Necessidades Nutricionais , Reprodução , Aves Canoras/fisiologia , Animais , Dieta , Feminino , Masculino , Estresse Fisiológico
19.
Genomics ; 97(4): 235-43, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21295131

RESUMO

The profiling of small RNAs by high-throughput sequencing (smRNA-Seq) has revealed the complexity of the RNA world. Here, we describe a computational scheme for dissecting the plant smRNAome by integrating smRNA-Seq datasets in Arabidopsis thaliana. Our analytical approach first defines ab initio the genomic loci that produce smRNAs as basic units, then utilizes principal component analysis (PCA) to predict novel miRNAs. Secondary structure prediction of candidates' putative precursors discovered a group of long hairpin double-stranded RNAs (lh-dsRNAs) formed by inverted duplications of decayed coding genes. These gene remnants produce miRNA-like small RNAs which are predominantly 21- and 22-nt long, dependent of DCL1 but independent of RDR2 and DCL2/3/4, and associated with AGO1. Additionally, we found two classes of transcription start site associated (TSSa) RNAs located at sense (+) and antisense (-) approximately 100-200 bp downstream of TSSs, but are differentially incorporated into AGO1 and AGO4, respectively.


Assuntos
Arabidopsis/genética , MicroRNAs/genética , RNA Interferente Pequeno/genética , Sítio de Iniciação de Transcrição , Proteínas de Arabidopsis/genética , Proteínas Argonautas , Biologia Computacional , Análise de Componente Principal/métodos , RNA de Cadeia Dupla/genética , RNA Polimerase Dependente de RNA/genética , Análise de Sequência de DNA
20.
Crit Care ; 14(2): 130, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20346100

RESUMO

Since the inception of blood banking, refinements in laboratory processes have allowed for progressively longer storage times of red blood cells. Whilst advantageous for the logistics of stock management, the clinical impact of the duration of red blood cell storage prior to transfusion remains uncertain, and a topic of growing interest.


Assuntos
Preservação de Sangue/efeitos adversos , Estado Terminal , Transfusão de Eritrócitos , Pesquisa Biomédica , Bancos de Sangue , Humanos , Fatores de Tempo
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