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1.
J Exp Bot ; 75(16): 4772-4783, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-38712747

RESUMO

Understanding phenology, its genetics and agronomic consequences, is critical for crop adaptation. Here we aim to (i) characterize lentil response to photoperiod with a focus on five loci: the lentil ELF3 orthologue Sn, two loci linked to clusters of lentil FT orthologues, and two loci without candidates in chromosomes 2 and 5 (Experiment 1: 36 lines, short and long days in a phytotron), and (ii) establish the phenology-yield relationship (Experiment 2: 25 lines, 11 field environments). A vintage perspective, where we quantify time trends in phenotype over three decades of breeding, links both experiments. Yield increased linearly from older to newer varieties at 29 kg ha-1 year-1 or 1.5% year-1, correlated negatively with flowering time in both winter- and summer-rainfall regimes, and decoupled from biomass in favourable environments. Time to flowering shortened from older to newer varieties at -0.56% year-1 in the field, and -0.42% year-1 (short days) and -0.99% year-1 (long days) in the phytotron. Early-flowering lines of diverse origin carried multiple early alleles for the five loci, indicating that at least some of these loci affect phenology additively. Current germplasm primarily features the early-flowering haplotype for an FTb cluster region, hence the potential to increase phenological diversity with yield implications.


Assuntos
Lens (Planta) , Sementes , Lens (Planta)/genética , Lens (Planta)/crescimento & desenvolvimento , Lens (Planta)/fisiologia , Sementes/crescimento & desenvolvimento , Sementes/genética , Fotoperíodo , Flores/crescimento & desenvolvimento , Flores/genética , Estações do Ano , Fenótipo
2.
Physiol Plant ; 176(4): e14412, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952339

RESUMO

Phytophthora root rot (PRR), caused by Phytophthora medicaginis, is a major soil-borne disease of chickpea in Australia. Breeding for PRR resistance is an effective approach to avoid significant yield loss. Genetic resistance has been identified in cultivated chickpea (Cicer arietinum) and in the wild relative C. echinospermum, with previous studies identifying independent genetic loci associated with each of these sources. However, the molecular mechanisms associated with PRR resistance are not known. RNA sequencing analysis employed in this study identified changes in gene expression in roots of three chickpea genotypes grown hydroponically, early post-infection with P. medicaginis zoospores. Analyses of differentially expressed genes (DEG) identified the activation of a higher number of non-specific R-genes in a PRR-susceptible variety than in the resistant genotypes, suggesting a whole plant resistance response occurring in chickpea against the pathogen. Contrasting molecular changes in signaling profiles, proteolysis and transcription factor pathways were observed in the cultivated and wild Cicer-derived resistant genotypes. DEG patterns supported a hypothesis that increased root elongation and reduced adventitious root formation limit the pathogen entry points in the genotype containing the wild Cicer source of PRR resistance. Candidate resistance genes, including an aquaporin and a maltose transporter in the wild Cicer source and GDSL esterases/lipases in the cultivated source of resistance, were oppositely regulated. Increased knowledge of these genes and pathways will improve our understanding of molecular mechanisms controlling PRR resistance in chickpea, and support the development of elite chickpea varieties through molecular breeding approaches.


Assuntos
Cicer , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Phytophthora , Doenças das Plantas , Raízes de Plantas , Análise de Sequência de RNA , Cicer/genética , Cicer/microbiologia , Cicer/fisiologia , Phytophthora/fisiologia , Phytophthora/patogenicidade , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/imunologia , Resistência à Doença/genética , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Genótipo
3.
Theor Appl Genet ; 135(1): 107-124, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34643761

RESUMO

KEY MESSAGE: QTL controlling vigour and related traits were identified in a chickpea RIL population and validated in diverse sets of germplasm. Robust KASP markers were developed for marker-assisted selection. To understand the genetic constitution of vigour in chickpea (Cicer arietinum L.), genomic data from a bi-parental population and multiple diversity panels were used to identify QTL, sequence-level haplotypes and genetic markers associated with vigour-related traits in Australian environments. Using 182 Recombinant Inbred Lines (RILs) derived from a cross between two desi varieties, Rupali and Genesis836, vigour QTL independent of flowering time were identified on chromosomes (Ca) 1, 3 and 4 with genotypic variance explained (GVE) ranging from 7.1 to 28.8%. Haplotype analysis, association analysis and graphical genotyping of whole-genome re-sequencing data of two diversity panels consisting of Australian and Indian genotypes and an ICRISAT Chickpea Reference Set revealed a deletion in the FTa1-FTa2-FTc gene cluster of Ca3 significantly associated with vigour and flowering time. Across the RIL population and diversity panels, the impact of the deletion was consistent for vigour but not flowering time. Vigour-related QTL on Ca4 co-located with a QTL for seed size in Rupali/Genesis836 (GVE = 61.3%). Using SNPs from this region, we developed and validated gene-based KASP markers across different panels. Two markers were developed for a gene on Ca1, myo -inositol monophosphatase (CaIMP), previously proposed to control seed size, seed germination and seedling growth in chickpea. While associated with vigour in the diversity panels, neither the markers nor broader haplotype linked to CaIMP was polymorphic in Rupali/Genesis836. Importantly, vigour appears to be controlled by different sets of QTL across time and with components which are independent from phenology.


Assuntos
Cicer/genética , Genoma de Planta , Cicer/crescimento & desenvolvimento , Estudos de Associação Genética , Marcadores Genéticos , Herança Multifatorial , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Sementes/anatomia & histologia , Sementes/genética
4.
Mol Breed ; 41(12): 78, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37309516

RESUMO

The root-lesion nematode Pratylenchus thornei Sher & Allen, 1953 is a damaging parasite of many crop plants, including the grain legume chickpea (Cicer arietinum L.). Within cultivated chickpea, there are no known sources of strong resistance to P. thornei, but some cultivars have partial resistance. In the research reported here, the genetic basis for differences in P. thornei resistance was analysed using a population derived by accelerated single seed descent from a cross between a partially resistant cultivar, PBA HatTrick, and a very susceptible cultivar, Kyabra. A genetic linkage map was constructed from genotyping-by-sequencing data. Two quantitative trait loci were mapped, one on the Ca4 chromosome and one on the Ca7 chromosome. The Ca7 locus had a greater and more consistent effect than the Ca4 locus. Marker assays designed for single nucleotide polymorphisms on Ca7 were applied to a panel of chickpea accessions. Some of these markers should be useful for marker-assisted selection in chickpea breeding. Haplotype analysis confirmed the Iranian landrace ICC14903 to be the source of the resistance allele in PBA HatTrick and indicated that other Australian cultivars inherited the same allele from other Iranian landraces. A candidate region was defined on the Ca7 pseudomolecule. Within that region, 69 genes have been predicted with high confidence. Among these, two have annotations related to biotic stress response. Three others have previously been reported to be expressed in roots of PBA HatTrick and Kyabra, including one that is more highly expressed in PBA HatTrick than in Kyabra. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01271-8.

5.
Nature ; 514(7520): 88-91, 2014 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-25043042

RESUMO

Environmental constraints severely restrict crop yields in most production environments, and expanding the use of variation will underpin future progress in breeding. In semi-arid environments boron toxicity constrains productivity, and genetic improvement is the only effective strategy for addressing the problem. Wheat breeders have sought and used available genetic diversity from landraces to maintain yield in these environments; however, the identity of the genes at the major tolerance loci was unknown. Here we describe the identification of near-identical, root-specific boron transporter genes underlying the two major-effect quantitative trait loci for boron tolerance in wheat, Bo1 and Bo4 (ref. 2). We show that tolerance to a high concentration of boron is associated with multiple genomic changes including tetraploid introgression, dispersed gene duplication, and variation in gene structure and transcript level. An allelic series was identified from a panel of bread and durum wheat cultivars and landraces originating from diverse agronomic zones. Our results demonstrate that, during selection, breeders have matched functionally different boron tolerance alleles to specific environments. The characterization of boron tolerance in wheat illustrates the power of the new wheat genomic resources to define key adaptive processes that have underpinned crop improvement.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Boro/farmacologia , Proteínas de Transporte/genética , Genes de Plantas/genética , Solo/química , Triticum/efeitos dos fármacos , Triticum/genética , Adaptação Fisiológica/genética , Alelos , Tolerância a Medicamentos , Duplicação Gênica/genética , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Poliploidia , Locos de Características Quantitativas/genética , RNA Mensageiro/análise , RNA Mensageiro/genética , RNA de Plantas/análise , RNA de Plantas/genética , Triticum/classificação , Triticum/fisiologia
6.
Plant Cell ; 28(1): 202-18, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26672067

RESUMO

Plant growth and survival depend upon the activity of membrane transporters that control the movement and distribution of solutes into, around, and out of plants. Although many plant transporters are known, their intrinsic properties make them difficult to study. In barley (Hordeum vulgare), the root anion-permeable transporter Bot1 plays a key role in tolerance to high soil boron, facilitating the efflux of borate from cells. However, its three-dimensional structure is unavailable and the molecular basis of its permeation function is unknown. Using an integrative platform of computational, biophysical, and biochemical tools as well as molecular biology, electrophysiology, and bioinformatics, we provide insight into the origin of transport function of Bot1. An atomistic model, supported by atomic force microscopy measurements, reveals that the protein folds into 13 transmembrane-spanning and five cytoplasmic α-helices. We predict a trimeric assembly of Bot1 and the presence of a Na(+) ion binding site, located in the proximity of a pore that conducts anions. Patch-clamp electrophysiology of Bot1 detects Na(+)-dependent polyvalent anion transport in a Nernstian manner with channel-like characteristics. Using alanine scanning, molecular dynamics simulations, and transport measurements, we show that conductance by Bot1 is abolished by removal of the Na(+) ion binding site. Our data enhance the understanding of the permeation functions of Bot1.


Assuntos
Hordeum/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Plantas/metabolismo , Sódio/metabolismo , Ânions/metabolismo , Sítios de Ligação , Boratos/metabolismo , Sistema Livre de Células , Simulação por Computador , Bicamadas Lipídicas/metabolismo , Lipossomos/metabolismo , Proteínas de Membrana Transportadoras/química , Modelos Moleculares , Permeabilidade , Pichia/metabolismo , Proteínas de Plantas/química , Dobramento de Proteína , Multimerização Proteica , Triticum/metabolismo
7.
Nurs Older People ; 28(1): 24-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26938608

RESUMO

In response to the need for appropriate and timely care of frail older patients admitted to hospital, a dedicated advanced nurse practitioner (ANP)-led referral service was developed. The service has continued to evolve over the 13 years since its implementation in accordance with changing service demands. This article describes the role of the ANP in care of the elderly/rehabilitation medicine and focuses on one area of clinical practice developed by the team: an ANP-led referral service. The aim of developing the service was to ensure that patients who required specialist care and rehabilitation could be identified and assessed as soon as possible after admission, with the premise that they could be transferred to a bed in care of the elderly medical wards. This was perceived by the ANPs to be advantageous for patients, who would receive care from a specialist team, and for care of the elderly staff who could use their knowledge and skills appropriately and safely.


Assuntos
Idoso Fragilizado , Enfermagem Geriátrica/métodos , Profissionais de Enfermagem , Papel do Profissional de Enfermagem , Encaminhamento e Consulta , Atenção Secundária à Saúde/métodos , Idoso , Idoso de 80 Anos ou mais , Humanos , Avaliação de Programas e Projetos de Saúde , Reino Unido
8.
BMC Plant Biol ; 15: 231, 2015 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-26410221

RESUMO

BACKGROUND: Boron (B) is an important micronutrient for plant growth, but is toxic when levels are too high. This commonly occurs in environments with alkaline soils and relatively low rainfall, including many of the cereal growing regions of southern Australia. Four major genetic loci controlling tolerance to high soil B have been identified in the landrace barley, Sahara 3771. Genes underlying two of the loci encode the B transporters HvBot1 and HvNIP2;1. RESULTS: We investigated sequence and expression level diversity in HvBot1 and HvNIP2;1 across barley germplasm, and identified five novel coding sequence alleles for HvBot1. Lines were identified containing either single or multiple copies of the Sahara HvBot1 allele. We established that only the tandemly duplicated Sahara allele conferred B tolerance, and this duplicated allele was found only in a set of nine lines accessioned in Australian collections as Sahara 3763-3771. HvNIP2;1 coding sequences were highly conserved across barley germplasm. We identified the likely causative SNP in the 5'UTR of Sahara HvNIP2;1, and propose that the creation of a small upstream open reading frame interferes with HvNIP2;1 translation in Sahara 3771. Similar to HvBot1, the tolerant HvNIP2;1 allele was unique to the Sahara barley accessions. We identified a new source of the 2H B tolerance allele controlling leaf symptom development, in the landrace Ethiopia 756. CONCLUSIONS: Ethiopia 756, as well as the cultivar Sloop Vic which carries both the 2H and HvBot1 B tolerance alleles derived from Sahara 3771, may be valuable as alternative parents in breeding programs targeted to high soil B environments. There is significant diversity in B toxicity tolerance among contemporary Australian barley varieties but this is not related to variation at any of the four known B tolerance loci, indicating that novel, as yet undiscovered, sources of tolerance exist.


Assuntos
Adaptação Fisiológica/genética , Boro/toxicidade , Variação Genética , Hordeum/genética , Hordeum/fisiologia , Adaptação Fisiológica/efeitos dos fármacos , Alelos , Cromossomos de Plantas/genética , Duplicação Gênica , Loci Gênicos , Hordeum/efeitos dos fármacos , Dados de Sequência Molecular , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo
9.
New Phytol ; 201(1): 131-143, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24033183

RESUMO

High expression of zinc (Zn)-regulated, iron-regulated transporter-like protein (ZIP) genes increases root Zn uptake in dicots, leading to high accumulation of Zn in shoots. However, none of the ZIP genes tested previously in monocots could enhance shoot Zn accumulation. In this report, barley (Hordeum vulgare) HvZIP7 was investigated for its functions in Zn transport. The functions of HvZIP7 in planta were studied using in situ hybridization and transient analysis of subcellular localization with a green fluorescent protein (GFP) reporter. Transgenic barley lines overexpressing HvZIP7 were also generated to further understand the functions of HvZIP7 in metal transport. HvZIP7 is strongly induced by Zn deficiency, primarily in vascular tissues of roots and leaves, and its protein was localized in the plasma membrane. These properties are similar to its closely related homologs in dicots. Overexpression of HvZIP7 in barley plants increased Zn uptake when moderately high concentrations of Zn were supplied. Significantly, there was a specific enhancement of shoot Zn accumulation, with no measurable increase in iron (Fe), manganese (Mn), copper (Cu) or cadmium (Cd). HvZIP7 displays characteristics of low-affinity Zn transport. The unique function of HvZIP7 provides new insights into the role of ZIP genes in Zn homeostasis in monocots, and offers opportunities to develop Zn biofortification strategies in cereals.


Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte de Cátions/genética , Expressão Gênica , Genes de Plantas , Hordeum/genética , Proteínas de Plantas/genética , Zinco/metabolismo , Transporte Biológico , Proteínas de Transporte/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Membrana Celular/metabolismo , Homeostase , Hordeum/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo
10.
Planta ; 237(4): 1111-22, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23277165

RESUMO

In cereals, a common salinity tolerance mechanism is to limit accumulation of Na(+) in the shoot. In a cross between the barley variety Barque-73 (Hordeum vulgare ssp. vulgare) and the accession CPI-71284 of wild barley (H. vulgare ssp. spontaneum), the HvNax3 locus on chromosome 7H was found to determine a ~10-25 % difference in leaf Na(+) accumulation in seedlings grown in saline hydroponics, with the beneficial exclusion trait originating from the wild parent. The Na(+) exclusion allele was also associated with a 13-21 % increase in shoot fresh weight. The HvNax3 locus was delimited to a 0.4 cM genetic interval, where it cosegregated with the HVP10 gene for vacuolar H(+)-pyrophosphatase (V-PPase). Sequencing revealed that the mapping parents encoded identical HVP10 proteins, but salinity-induced mRNA expression of HVP10 was higher in CPI-71284 than in Barque-73, in both roots and shoots. By contrast, the expression of several other genes predicted by comparative mapping to be located in the HvNax3 interval was similar in the two parent lines. Previous work demonstrated roles for V-PPase in ion transport and salinity tolerance. We therefore considered transcription levels of HVP10 to be a possible basis for variation in shoot Na(+) accumulation and biomass production controlled by the HvNax3 locus under saline conditions. Potential mechanisms linking HVP10 expression patterns to the observed phenotypes are discussed.


Assuntos
Hordeum/genética , Pirofosfatase Inorgânica/genética , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Genoma de Planta , Hordeum/enzimologia , RNA Mensageiro/metabolismo , Análise de Sequência de DNA
11.
Mutagenesis ; 28(2): 227-32, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23340811

RESUMO

A novel selective glucocorticoid receptor (GR) agonist, AZD2906, was found to increase the incidence of micronucleated immature erythrocytes (MIE) in the bone marrow of rats given two oral doses at the maximum tolerated level. Because GR agonists as a class are considered not to be genotoxic and AZD2906 showed no activity in the standard in vitro tests or in vivo in a rat liver comet assay, investigative studies were performed to compare AZD2906 with a reference traditional GR agonist, prednisolone. Emphasis was placed on blood and bone marrow parameters in these studies because GR activation has been reported to induce erythropoiesis which, in turn, is known to increase MIE in the bone marrow. Both compounds induced almost identical, small increases in micronucleus frequency at all doses tested. Directly comparable changes in haematological and bone marrow parameters were also seen with significant decreases in lymphoid cells in both compartments and significant increases in numbers of circulating neutrophils. Although no evidence of increased erythropoiesis was seen as increased immature erythrocyte numbers either in the blood or in the bone marrow, histopathological examination showed focal areas in the bone marrow where the erythroid population was enriched in association with an atrophic myeloid lineage. This could have been due to direct stimulation of the erythroid lineage or a secondary effect of myelosuppression inducing a rebound increase in erythropoiesis into the vacant haematopoietic cell compartment. It was concluded that the increased MIE frequencies induced by both AZD2906 and prednisolone are a consequence of their pharmacological effects on the bone marrow, either by directly inducing erythropoiesis or by some other unknown effect on cellular function, and do not indicate potential genotoxicity. This conclusion is supported by the lack of carcinogenic risk in man demonstrated by decades of clinical use of prednisolone and other GR agonists.


Assuntos
Medula Óssea/efeitos dos fármacos , Testes para Micronúcleos/métodos , Piridinas/farmacologia , Receptores de Glucocorticoides/agonistas , Administração Oral , Animais , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Eritropoese/efeitos dos fármacos , Sistema Hematopoético/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Masculino , Prednisolona/farmacologia , Ratos , Ratos Wistar
12.
Elife ; 122023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36912783

RESUMO

In isolation from their peers, Photinus carolinus fireflies flash with no intrinsic period between successive bursts. Yet, when congregating into large mating swarms, these fireflies transition into predictability, synchronizing with their neighbors with a rhythmic periodicity. Here we propose a mechanism for emergence of synchrony and periodicity, and formulate the principle in a mathematical framework. Remarkably, with no fitting parameters, analytic predictions from this simple principle and framework agree strikingly well with data. Next, we add further sophistication to the framework using a computational approach featuring groups of random oscillators via integrate-and-fire interactions controlled by a tunable parameter. This agent-based framework of P. carolinus fireflies interacting in swarms of increasing density also shows quantitatively similar phenomenology and reduces to the analytic framework in the appropriate limit of the tunable coupling strength. We discuss our findings and note that the resulting dynamics follow the style of a decentralized follow-the-leader synchronization, where any of the randomly flashing individuals may take the role of the leader of any subsequent synchronized flash burst.

13.
J Innov Card Rhythm Manag ; 14(10): 5605-5609, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37927396

RESUMO

Elevated right ventricular pacing (RVP) burdens are associated with the development of pacing-induced cardiomyopathy. This association is alluded to in the recent European and American pacing guidelines where anticipated pacing burden forms part of the indications for conduction system pacing. Understanding the temporal pattern of RVP burden is important with respect to anticipating future burden and ensuring that the most appropriate pacing modality is selected for patients. To the best of our knowledge, this is the first study to assess how RVP burden changes over time in different pacing indications. A retrospective, single-center, observational study was performed. RVP burdens from pacing checks were extracted and plotted against 6-month time "bins." Graphical plots of RVP burdens for different pacing indications were produced. There was no significant change in the RVP burden across time, independent of the initial pacing indication. Individuals with sinus node disease (SND) and a P-R interval of >250 ms had increased RVP burden. Other than patients with SND and a P-R interval of <250 ms, individuals had pacing burdens higher than those proposed in both the European and American pacing guidelines for conduction system pacing.

14.
J Am Med Inform Assoc ; 30(7): 1293-1300, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37192819

RESUMO

Research increasingly relies on interrogating large-scale data resources. The NIH National Heart, Lung, and Blood Institute developed the NHLBI BioData CatalystⓇ (BDC), a community-driven ecosystem where researchers, including bench and clinical scientists, statisticians, and algorithm developers, find, access, share, store, and compute on large-scale datasets. This ecosystem provides secure, cloud-based workspaces, user authentication and authorization, search, tools and workflows, applications, and new innovative features to address community needs, including exploratory data analysis, genomic and imaging tools, tools for reproducibility, and improved interoperability with other NIH data science platforms. BDC offers straightforward access to large-scale datasets and computational resources that support precision medicine for heart, lung, blood, and sleep conditions, leveraging separately developed and managed platforms to maximize flexibility based on researcher needs, expertise, and backgrounds. Through the NHLBI BioData Catalyst Fellows Program, BDC facilitates scientific discoveries and technological advances. BDC also facilitated accelerated research on the coronavirus disease-2019 (COVID-19) pandemic.


Assuntos
COVID-19 , Computação em Nuvem , Humanos , Ecossistema , Reprodutibilidade dos Testes , Pulmão , Software
15.
Mutagenesis ; 27(5): 533-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22492203

RESUMO

Although there are several in vivo tests for potential genotoxicity, with the possible exception of the transgenic rodent mutation models, none is specifically intended to assess increasing damage with chronic administration. In principle, peripheral blood lymphocytes would be expected to accumulate DNA damage with repeated dosing because the majority are not in active division and appear to have limited DNA repair capability, and they are exposed to plasma levels of test materials and metabolites. However, there appear to be no published reports confirming this principle. Therefore, in the current study, after optimising culture conditions for rat lymphocytes in this laboratory, rats were given oral doses of cyclophosphamide or hexamethylphosphoramide (HMPA) for up to 28 days and peripheral lymphocytes analysed for chromosome aberrations at various time points. The results clearly show that, for both compounds, doses that gave no significant increases in aberration frequency after 2 days induced clear increases after 15 days with further damage detectable after 28 doses. With HMPA, it was shown that DNA damage persisted for at least 10 days after cessation of treatment. These data show that repeat dose studies in the rat measuring chromosome aberration frequency in lymphocytes can give a genuine indication that genotoxicity may increase with chronic administration and, therefore, maybe useful in assessing the risk of potentially genotoxic substances.


Assuntos
Aberrações Cromossômicas/induzido quimicamente , Ciclofosfamida/toxicidade , Hempa/toxicidade , Linfócitos/efeitos dos fármacos , Mutagênicos/toxicidade , Animais , Células Cultivadas , Ciclofosfamida/administração & dosagem , Ciclofosfamida/farmacologia , Hempa/administração & dosagem , Hempa/farmacologia , Linfócitos/metabolismo , Masculino , Testes de Mutagenicidade , Mutagênicos/administração & dosagem , Mutagênicos/farmacologia , Ratos
16.
Front Plant Sci ; 13: 829566, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35283931

RESUMO

Plant vigor is a complex trait for which the underlying molecular control mechanisms remain unclear. Vigorous plants tend to derive from larger seeds and have greater early canopy cover, often with bigger leaves. In this study, we delimited the size of a major vigor quantitative trait locus (QTL) on chickpea chromosome 4-104.4 kb, using recombinant association analysis in 15 different heterogeneous inbred families, derived from a Rupali/Genesis836 recombinant inbred line population. The phenotypic and molecular genetic analysis provided evidence for a role of the gene Ca4_TIFY4B, in determining leaf and seed size in chickpea. A non-synonymous single-nucleotide polymorphism (SNP) in the high-vigor parent was located inside the core motif TIFYCG, resulting in a residue change T[I/S]FYCG. Complexes formed by orthologs of Ca4_TIFY4B (PEAPOD in Arabidopsis), Novel Interactor of JAZ (CaNINJA), and other protein partners are reported to act as repressors regulating the transcription of downstream genes that control plant organ size. When tested in a yeast 2-hybrid (Y2H) assay, this residue change suppressed the interaction between Ca4_TIFY4B and CaNINJA. This is the first report of a naturally occurring variant of the TIFY family in plants. A robust gene-derived molecular marker is available for selection in chickpea for seed and plant organ size, i.e., key component traits of vigor.

17.
Plant Physiol ; 153(4): 1706-15, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20581256

RESUMO

Boron (B) toxicity is a significant limitation to cereal crop production in a number of regions worldwide. Here we describe the cloning of a gene from barley (Hordeum vulgare), underlying the chromosome 6H B toxicity tolerance quantitative trait locus. It is the second B toxicity tolerance gene identified in barley. Previously, we identified the gene Bot1 that functions as an efflux transporter in B toxicity-tolerant barley to move B out of the plant. The gene identified in this work encodes HvNIP2;1, an aquaporin from the nodulin-26-like intrinsic protein (NIP) subfamily that was recently described as a silicon influx transporter in barley and rice (Oryza sativa). Here we show that a rice mutant for this gene also shows reduced B accumulation in leaf blades compared to wild type and that the mutant protein alters growth of yeast (Saccharomyces cerevisiae) under high B. HvNIP2;1 facilitates significant transport of B when expressed in Xenopus oocytes compared to controls and to another NIP (NOD26), and also in yeast plasma membranes that appear to have relatively high B permeability. We propose that tolerance to high soil B is mediated by reduced expression of HvNIP2;1 to limit B uptake, as well as by increased expression of Bot1 to remove B from roots and sensitive tissues. Together with Bot1, the multifunctional aquaporin HvNIP2;1 is an important determinant of B toxicity tolerance in barley.


Assuntos
Aquaporinas/metabolismo , Boro/toxicidade , Hordeum/genética , Proteínas de Plantas/metabolismo , Animais , Aquaporinas/genética , Mapeamento Cromossômico , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Hordeum/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Oócitos , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Locos de Características Quantitativas , Saccharomyces cerevisiae/crescimento & desenvolvimento , Xenopus
18.
Mutat Res ; 726(1): 36-41, 2011 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-21889997

RESUMO

A semi-automated scoring system has been developed to provide rapid, accurate assessment of micronuclei in preparations of mononuclear mouse lymphoma L5178Y cells. Following exposure to a range of test agents, flat, single-cell preparations were produced from exponentially growing cultures by cytocentrifugation. Following staining with 4'-6-diamidino-2-phenylindole (DAPI), cells were scanned by use of the MicroNuc module of Metafer 4 v 3.4.102, after modifying the classifier developed for selecting micronuclei in binucleate cells to increase its sensitivity. The image gallery of all cells was then sorted to bring aberrant cells to the top of the gallery to assess visually the numbers of cells with micronuclei, as distinct from other debris. Slide quality was shown to be paramount in obtaining accurate results from an automated scan and the data obtained compared very well with the incidence of micronuclei scored conventionally by microscopy. Compared with manual scoring the time saving is considerable, as more than 2000 images are captured in approximately 2min, with subsequent visual assessment of aberrant cells in the image gallery taking about 1-2min/slide. By scanning all aberrant cells, the system also captures additional information on necrotic, apoptotic and fragmented cells. Although optimised for mouse lymphoma cells, it should be simple to adapt the method for any cell type growing in suspension.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Testes para Micronúcleos/métodos , Animais , Leucemia L5178 , Camundongos , Micronúcleos com Defeito Cromossômico , Mutagênicos/toxicidade , Sensibilidade e Especificidade
19.
Sci Adv ; 7(28)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34233879

RESUMO

Fireflies flashing in unison is a mesmerizing manifestation of animal collective behavior and an archetype of biological synchrony. To elucidate synchronization mechanisms and inform theoretical models, we recorded the collective display of thousands of Photinus carolinus fireflies in natural swarms, and provide the first spatiotemporal description of the onset of synchronization. At low firefly density, flashes appear uncorrelated. At high density, the swarm produces synchronous flashes within periodic bursts. Using three-dimensional reconstruction, we demonstrate that flash bursts nucleate and propagate across the swarm in a relay-like process. Our results suggest that fireflies interact locally through a dynamic network of visual connections defined by visual occlusion from terrain and vegetation. This model illuminates the importance of the environment in shaping self-organization and collective behavior.

20.
JMIR Public Health Surveill ; 7(9): e29310, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34298500

RESUMO

BACKGROUND: As the world faced the pandemic caused by the novel coronavirus disease 2019 (COVID-19), medical professionals, technologists, community leaders, and policy makers sought to understand how best to leverage data for public health surveillance and community education. With this complex public health problem, North Carolinians relied on data from state, federal, and global health organizations to increase their understanding of the pandemic and guide decision-making. OBJECTIVE: We aimed to describe the role that stakeholders involved in COVID-19-related data played in managing the pandemic in North Carolina. The study investigated the processes used by organizations throughout the state in using, collecting, and reporting COVID-19 data. METHODS: We used an exploratory qualitative study design to investigate North Carolina's COVID-19 data collection efforts. To better understand these processes, key informant interviews were conducted with employees from organizations that collected COVID-19 data across the state. We developed an interview guide, and open-ended semistructured interviews were conducted during the period from June through November 2020. Interviews lasted between 30 and 45 minutes and were conducted by data scientists by videoconference. Data were subsequently analyzed using qualitative data analysis software. RESULTS: Results indicated that electronic health records were primary sources of COVID-19 data. Often, data were also used to create dashboards to inform the public or other health professionals, to aid in decision-making, or for reporting purposes. Cross-sector collaboration was cited as a major success. Consistency among metrics and data definitions, data collection processes, and contact tracing were cited as challenges. CONCLUSIONS: Findings suggest that, during future outbreaks, organizations across regions could benefit from data centralization and data governance. Data should be publicly accessible and in a user-friendly format. Additionally, established cross-sector collaboration networks are demonstrably beneficial for public health professionals across the state as these established relationships facilitate a rapid response to evolving public health challenges.


Assuntos
COVID-19/epidemiologia , Análise de Dados , Coleta de Dados , Pandemias/prevenção & controle , Participação dos Interessados/psicologia , Feminino , Educação em Saúde , Humanos , Masculino , North Carolina/epidemiologia , Vigilância em Saúde Pública , Pesquisa Qualitativa
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