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1.
Plant Cell ; 35(9): 3303-3324, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37220754

RESUMO

Flowering is the transition from vegetative to reproductive growth and is critical for plant adaptation and reproduction. FLOWERING LOCUS C (FLC) plays a central role in flowering time control, and dissecting its regulation mechanism provides essential information for crop improvement. Here, we report that DECAPPING5 (DCP5), a component of processing bodies (P-bodies), regulates FLC transcription and flowering time in Arabidopsis (Arabidopsis thaliana). DCP5 and its interacting partner SISTER OF FCA (SSF) undergo liquid-liquid phase separation (LLPS) that is mediated by their prion-like domains (PrDs). Enhancing or attenuating the LLPS of both proteins using transgenic methods greatly affects their ability to regulate FLC and flowering time. DCP5 regulates FLC transcription by modulating RNA polymerase II enrichment at the FLC locus. DCP5 requires SSF for FLC regulation, and loss of SSF or its PrD disrupts DCP5 function. Our results reveal that DCP5 interacts with SSF, and the nuclear DCP5-SSF complex regulates FLC expression at the transcriptional level.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Flores/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Mutação , Corpos de Processamento , Reprodução
2.
BMC Plant Biol ; 24(1): 188, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38486139

RESUMO

BACKGROUND: Proper flowering time is important for the growth and development of plants, and both too early and too late flowering impose strong negative influences on plant adaptation and seed yield. Thus, it is vitally important to study the mechanism underlying flowering time control in plants. In a previous study by the authors, genome-wide association analysis was used to screen the candidate gene SISTER OF FCA (SSF) that regulates FLOWERING LOCUS C (FLC), a central gene encoding a flowering suppressor in Arabidopsis thaliana. RESULTS: SSF physically interacts with Protein arginine methyltransferase 5 (PRMT5, SKB1). Subcellular co-localization analysis showed that SSF and SKB1 interact in the nucleus. Genetically, SSF and SKB1 exist in the same regulatory pathway that controls FLC expression. Furthermore, RNA-sequencing analysis showed that both SSF and SKB1 regulate certain common pathways. CONCLUSIONS: This study shows that PRMT5 interacts with SSF, thus controlling FLC expression and facilitating flowering time control.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo
3.
Phys Rev Lett ; 132(1): 016501, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38242670

RESUMO

We use resonant inelastic x-ray scattering (RIXS) at the Fe-L_{3} edge to study the spin excitations of uniaxial-strained and unstrained FeSe_{1-x}S_{x} (0≤x≤0.21) samples. The measurements on unstrained samples reveal dispersive spin excitations in all doping levels, which show only minor doping dependence in energy dispersion, lifetime, and intensity, indicating that high-energy spin excitations are only marginally affected by sulfur doping. RIXS measurements on uniaxial-strained samples reveal that the high-energy spin-excitation anisotropy observed previously in FeSe is also present in the doping range 0200 K in x=0.18 and reaches a maximum around the nematic quantum critical doping (x_{c}≈0.17). Since the spin-excitation anisotropy directly reflects the existence of nematic spin correlations, our results indicate that high-energy nematic spin correlations pervade the regime of nematicity in the phase diagram and are enhanced by the nematic quantum criticality. These results emphasize the essential role of spin fluctuations in driving electronic nematicity and highlight the capability of uniaxial strain in tuning spin excitations in quantum materials hosting strong magnetoelastic coupling and electronic nematicity.

4.
J Chem Phys ; 160(21)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38832731

RESUMO

We propose an efficient version of ensemble Hartree-Fock/density functional theory to calculate a set of two charge-transfer states for systems with odd-numbers of electrons. The approach does require definitions of donor/acceptor fragments; however, the approach is not very sensitive to such definitions-even in the limit of very strong electronic coupling. The key ansatz is that, by mandating that the vector space spanned by the active orbitals projects equally onto the donor and acceptor fragments, such a constraint eliminates all intra-molecular local excitations and makes it far easier to generate potential energy surfaces that are smooth over a wide region of configuration space. The method is fast, working with only two electron configurations, and should be useful for ab initio non-adiabatic dynamics in the near future.

5.
J Chem Phys ; 160(5)2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38310474

RESUMO

We show that standard Ehrenfest dynamics does not conserve linear and angular momentum when using a basis of truncated adiabatic states. However, we also show that previously proposed effective Ehrenfest equations of motion [M. Amano and K. Takatsuka, "Quantum fluctuation of electronic wave-packet dynamics coupled with classical nuclear motions," J. Chem. Phys. 122, 084113 (2005) and V. Krishna, "Path integral formulation for quantum nonadiabatic dynamics and the mixed quantum classical limit," J. Chem. Phys. 126, 134107 (2007)] involving the non-Abelian Berry force do maintain momentum conservation. As a numerical example, we investigate the Kramers doublet of the methoxy radical using generalized Hartree-Fock with spin-orbit coupling and confirm that angular momentum is conserved with the proper equations of motion. Our work makes clear some of the limitations of the Born-Oppenheimer approximation when using ab initio electronic structure theory to treat systems with unpaired electronic spin degrees of freedom, and we demonstrate that Ehrenfest dynamics can offer much improved, qualitatively correct results.

6.
J Chem Phys ; 160(12)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38526113

RESUMO

Within the context of fewest-switch surface hopping (FSSH) dynamics, one often wishes to remove the angular component of the derivative coupling between states J and K. In a previous set of papers, Shu et al. [J. Phys. Chem. Lett. 11, 1135-1140 (2020)] posited one approach for such a removal based on direct projection, while we isolated a second approach by constructing and differentiating a rotationally invariant basis. Unfortunately, neither approach was able to demonstrate a one-electron operatorÔ whose matrix element JÔK was the angular component of the derivative coupling. Here, we show that a one-electron operator can, in fact, be constructed efficiently in a semi-local fashion. The present results yield physical insight into designing new surface hopping algorithms and are of immediate use for FSSH calculations.

7.
J Chem Phys ; 160(12)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38526114

RESUMO

Modern electronic structure theory is built around the Born-Oppenheimer approximation and the construction of an electronic Hamiltonian Hel(X) that depends on the nuclear position X (and not the nuclear momentum P). In this article, using the well-known theory of electron translation (Γ') and rotational (Γ″) factors to couple electronic transitions to nuclear motion, we construct a practical phase-space electronic Hamiltonian that depends on both nuclear position and momentum, HPS(X,P). While classical Born-Oppenheimer dynamics that run along the eigensurfaces of the operator Hel(X) can recover many nuclear properties correctly, we present some evidence that motion along the eigensurfaces of HPS(X,P) can better capture both nuclear and electronic properties (including the elusive electronic momentum studied by Nafie). Moreover, only the latter (as opposed to the former) conserves the total linear and angular momentum in general.

8.
World J Surg Oncol ; 22(1): 110, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38664770

RESUMO

BACKGROUND: Octamer-binding transcription factor 4-positive circulating tumor cell (OCT4+CTC) exhibits high stemness and invasive potential, which may influence the efficacy of immune checkpoint inhibitors (ICI). This study aimed to assess the prognostic role of OCT4+CTC in advanced cholangiocarcinoma (CCA) patients who received ICI treatment. METHODS: In total, 40 advanced CCA patients who received ICI treatment were included, and CTC and OCT4 counts were detected via a Canpatrol system and an RNA in situ hybridization method before ICI treatment. Patients were subsequently divided into none CTC, OCT4-CTC, and OCT4+CTC groups. Patients were followed up for a median of 10.4 months. RESULTS: The percentages of patients in none CTC, OCT4-CTC, and OCT4+CTC groups were 25.0%, 30.0%, and 45.0%, respectively. The proportion of patients with lymph node metastasis was highest in OCT4+CTC group, followed by none CTC group, and lowest in OCT4-CTC group (P = 0.025). The objective response rate (ORR) was lowest in OCT4+CTC group, moderate in OCT4-CTC group, and highest in none CTC group (P = 0.009), while disease control rate was not different among three groups (P = 0.293). In addition, progression-free survival (PFS) (P < 0.001) and overall survival (OS) (P = 0.001) were shorter in the OCT4+CTC group than in none CTC & OCT4-CTC group. Moreover, OCT4+CTC (versus none CTC) was independently linked with poorer PFS [hazard ratio (HR) = 6.752, P = 0.001] and OS (HR = 6.674, P = 0.003) in advanced CCA patients. CONCLUSION: OCT4+CTC relates to lymph node metastasis and shows a good predictive value for poor treatment response and survival in advanced CCA patients who receive ICI treatment.


Assuntos
Neoplasias dos Ductos Biliares , Biomarcadores Tumorais , Colangiocarcinoma , Inibidores de Checkpoint Imunológico , Células Neoplásicas Circulantes , Fator 3 de Transcrição de Octâmero , Humanos , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/patologia , Colangiocarcinoma/mortalidade , Colangiocarcinoma/sangue , Masculino , Feminino , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/mortalidade , Neoplasias dos Ductos Biliares/sangue , Células Neoplásicas Circulantes/patologia , Células Neoplásicas Circulantes/metabolismo , Pessoa de Meia-Idade , Fator 3 de Transcrição de Octâmero/metabolismo , Inibidores de Checkpoint Imunológico/uso terapêutico , Prognóstico , Taxa de Sobrevida , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Seguimentos , Idoso , Adulto , Metástase Linfática , Estudos Retrospectivos
9.
J Environ Manage ; 353: 120143, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38301477

RESUMO

The application of nitrification inhibitors (nitrapyrin) and urease inhibitors (N-(N-butyl) thiophosphoric triamide) under conventional water resources has been considered as an effective means to improve nitrogen utilization efficiency and mitigate soil greenhouse gas emissions. However, it is not known whether the inhibitors still have an inhibitory effect under unconventional water resources (reclaimed water and livestock wastewater) irrigation and whether their use in combination with biochar improves the mitigation effect. Therefore, unconventional water resources were used for irrigation, with groundwater (GW) control. Nitrapyrin and N-(N-butyl) thiophosphoric triamide were used alone or in combination with biochar in a pot experiment, and CO2, N2O, and CH4 emissions were measured. The results showed that irrigation of unconventional water resources exacerbated global warming potential (GWP). All exogenous substance treatments increased CO2 and CH4 emissions and suppressed N2O emissions, independent of the type of water, compared to no substances (NS). The inhibitors were ineffective in reducing the GWP whether or not in combination with biochar, and the combined application of inhibitors with biochar further increased the GWP. This study suggests that using inhibitors and biochar in combination to regulate the greenhouse effect under unconventional water resources irrigation should be done with caution.


Assuntos
Agricultura , Carvão Vegetal , Gado , Compostos Organofosforados , Animais , Agricultura/métodos , Águas Residuárias , Aquecimento Global , Dióxido de Carbono/análise , Óxido Nitroso/análise , Solo , Fertilizantes , Metano
10.
Plant Cell Environ ; 46(3): 946-961, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36582057

RESUMO

The lepidopteran crop pest Plutella xylostella causes severe constraints on Brassica cultivation. Here, we report a novel role for RPX1 (resistance to P. xylostella) in resistance to this pest in Arabidopsis thaliana. The rpx1-1 mutant repels P. xylostella larvae, and feeding on the rpx1-1 mutant severely damages the peritrophic matrix structure in the midgut of the larvae, thereby negatively affecting larval growth and pupation. This resistance results from the accumulation of defence compounds, including the homoterpene (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), due to the upregulation of PENTACYCLIC TRITERPENE SYNTHASE 1 (PEN1), which encodes a key DMNT biosynthetic enzyme. P. xylostella infestation and wounding induce RPX1 protein degradation, which may confer a rapid response to insect infestation. RPX1 inactivation and PEN1 overexpression are not associated with negative trade-offs for plant growth but have much higher seed production than the wild-type in the presence of P. xylostella infestation. This study offers a new strategy for plant molecular breeding against P. xylostella.


Assuntos
Arabidopsis , Brassica , Mariposas , Triterpenos , Animais , Arabidopsis/genética , Mariposas/fisiologia , Larva/fisiologia , Triterpenos/metabolismo , Brassica/metabolismo
11.
J Exp Bot ; 74(12): 3749-3764, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-36964900

RESUMO

The corn leaf aphid (Rhopalosiphum maidis) is a major maize pest that frequently causes substantial yield losses. Exploring the genetic basis of resistance to aphids is important for improving maize yield and quality. Here, we used a maize recombinant inbred line population derived from two parents with different susceptibility to aphids, B73 (susceptible) and Abe2 (resistant), and performed quantitative trait locus (QTL) mapping using aphid resistance scores as an indicator. We mapped a stable QTL, qRTA6, to chromosome 6 using data from 2 years of field trials, which explained 40.12-55.17% of the phenotypic variation. To further investigate the mechanism of aphid resistance in Abe2, we constructed transcriptome and metabolome libraries from Abe2 and B73 leaves with or without aphid infestation at different time points. Integrating QTL mapping and transcriptome data revealed three aphid resistance candidate genes (Zm00001d035736, Zm00001d035751, and Zm00001d035767) associated with the hypersensitive response, the jasmonic acid pathway, and protein ubiquitination. Integrated transcriptomic and metabolomic analysis revealed that the differentially expressed genes and metabolites were enriched in flavonoid biosynthesis. These findings extend our understanding of the molecular mechanisms controlling aphid resistance in maize, and the QTL and candidate genes are valuable resources for increasing this resistance.


Assuntos
Afídeos , Animais , Afídeos/fisiologia , Zea mays/genética , Zea mays/metabolismo , Locos de Características Quantitativas , Multiômica , Folhas de Planta/genética
12.
J Phys Chem A ; 127(16): 3591-3597, 2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37067426

RESUMO

While spin-orbit coupling (SOC) is typically the dominant interaction that couples singlet and triplet states within individual chromophores, hyperfine coupling (HFC) becomes important in multichromophoric systems, particularly in relation to the radical pair mechanism. Here, we use TD-DFT to calculate the spin-orbit coupling and hyperfine coupling between the first singlet and triplet charge transfer states of the radical pair 2Pyrene- and 2N,N-dimethylaniline+. We show that, as the intermolecular donor-acceptor distance grows, SOC decays to zero (as one would expect) because singlet and triplet states are characterized by identical orbitals in space, while the HFC remains comparatively constant. The switching region occurs around 4 Å, beyond which HFC dominates over SOC as far as defining the rate of intersystem crossing (ISC).

13.
J Chem Phys ; 159(11)2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37728203

RESUMO

For a system without spin-orbit coupling, the (i) nuclear plus electronic linear momentum and (ii) nuclear plus orbital electronic angular momentum are good quantum numbers. Thus, when a molecular system undergoes a nonadiabatic transition, there should be no change in the total linear or angular momentum. Now, the standard surface hopping algorithm ignores the electronic momentum and indirectly equates the momentum of the nuclear degrees of freedom to the total momentum. However, even with this simplification, the algorithm still does not conserve either the nuclear linear or the nuclear angular momenta. Here, we show that one way to address these failures is to dress the derivative couplings (i.e., the hopping directions) in two ways: (i) we disallow changes in the nuclear linear momentum by working in a translating basis (which is well known and leads to electron translation factors) and (ii) we disallow changes in the nuclear angular momentum by working in a basis that rotates around the center of mass [which is not well-known and leads to a novel, rotationally removable component of the derivative coupling that we will call electron rotation factors below, cf. Eq. (96)]. The present findings should be helpful in the short term as far as interpreting surface hopping calculations for singlet systems (without spin) and then developing the new surface hopping algorithm in the long term for systems where one cannot ignore the electronic orbital and/or spin angular momentum.

14.
Arch Womens Ment Health ; 26(2): 259-267, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36738337

RESUMO

Sleep disorders are common among pregnant females. However, its association with postpartum depression (PPD) is unknown. We aimed to assess if sleep disorders during pregnancy increase the risk of PPD by a systematic review. The databases of PubMed, CENTRAL, ScienceDirect, Embase, and Google Scholar were searched for studies reporting the association between any type of sleep disorder during pregnancy and the risk of PPD. Effect sizes were pooled in a random-effects model. Sixteen studies with data of 12,614 women were included. Meta-analysis indicated that sleep disorders during pregnancy resulted in a statistically significant increased risk of PPD (OR: 2.36 95% CI: 1.72, 2.32). The overall result had high heterogeneity (I2 = 84%). Sub-group analysis based on study location (Asian vs Western), sample size (> 500 vs < 500), depression scale, and PPD assessment time did not change the results. However, we found that only poor sleep quality but not insomnia was associated with PPD. The risk was also increased only with sleep disorders measured in the 3rd trimester but not for the 1st and 2nd trimesters. Evidence suggests that sleep disorders during pregnancy may increase risk of PPD. The risk is high for sleep disorders occurring in the 3rd trimester. Based on these findings, there is a need for thorough screening and subsequent corrective measures to ensure adequate and quality sleep among pregnant females.


Assuntos
Depressão Pós-Parto , Distúrbios do Início e da Manutenção do Sono , Transtornos do Sono-Vigília , Gravidez , Feminino , Humanos , Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/epidemiologia , Depressão Pós-Parto/etiologia , Terceiro Trimestre da Gravidez , Segundo Trimestre da Gravidez , Distúrbios do Início e da Manutenção do Sono/complicações , Transtornos do Sono-Vigília/complicações , Transtornos do Sono-Vigília/epidemiologia , Fatores de Risco
15.
J Fish Dis ; 46(3): 229-238, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36484113

RESUMO

Pseudomonas plecoglossicida is an important pathogenic bacterium in aquaculture that causes visceral granulomas in large yellow croaker (Larimichthys crocea). Uridine diphosphate glucose phosphorylase encoded by galU plays a key role in biosynthesis of the bacterial envelope, particularly lipopolysaccharide and the capsule. In this study, we inactivated the galU gene in the P. plecoglossicida isolate XSDHY-P. The galU mutant strain showed impaired growth in the early exponential stage and lacked the O polysaccharide side chain in lipopolysaccharide, but almost no defect in biofilm formation was detected. The galU mutant strain also exhibited significantly more sensitivity to the bactericidal action of normal fish serum mediated by the complement system compared to the wild-type strain. In a cell model originating from the head kidney of large yellow croaker, the galU mutant strain showed lower capacities of adhesion, invasion, and intracellular survival compared to the wild-type strain. In addition, the deficiency of the galU mutant drastically decreased bacterial loads in tissues and attenuated P. plecoglossicida virulence in fish. These results suggest that the galU gene of P. plecoglossicida is required for in vivo survival in large yellow croaker.


Assuntos
Doenças dos Peixes , Perciformes , Infecções por Pseudomonas , Animais , Infecções por Pseudomonas/microbiologia , Lipopolissacarídeos , Doenças dos Peixes/microbiologia , Perciformes/microbiologia
16.
Genes Dev ; 29(7): 696-701, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25805848

RESUMO

The extent to which natural polymorphisms in noncoding sequences have functional consequences is still unknown. A large proportion of the natural variation in flowering in Arabidopsis thaliana accessions is due to noncoding cis polymorphisms that define distinct haplotypes of FLOWERING LOCUS C (FLC). Here, we show that a single natural intronic polymorphism in one haplotype affects FLC expression and thus flowering by specifically changing splicing of the FLC antisense transcript COOLAIR. Altered antisense splicing increases FLC expression via a cotranscriptional mechanism involving capping of the FLC nascent transcript. Single noncoding polymorphisms can therefore be a major contributor to phenotypic evolution through modulation of noncoding transcripts.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Evolução Biológica , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/genética , RNA não Traduzido/genética , Proteínas de Arabidopsis/metabolismo , Splicing de RNA , RNA não Traduzido/metabolismo
17.
Int J Mol Sci ; 24(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36982663

RESUMO

We investigated the expression and biological function of retinoic acid inducible gene I (RIG-I) in esophageal squamous cell carcinoma (ESCC). Materials and methods: An immunohistochemical analysis was performed on 86 pairs of tumor tissue and adjacent normal tissue samples of patients with ESCC. We generated RIG-I-overexpressing ESCC cell lines KYSE70 and KYSE450, and RIG-I- knockdown cell lines KYSE150 and KYSE510. Cell viability, migration and invasion, radioresistance, DNA damage, and cell cycle were evaluated using CCK-8, wound-healing and transwell assay, colony formation, immunofluorescence, and flow cytometry and Western blotting, respectively. RNA sequencing was performed to determine the differential gene expression between controls and RIG-I knockdown. Tumor growth and radioresistance were assessed in nude mice using xenograft models. RIG-I expression was higher in ESCC tissues compared with that in matched non-tumor tissues. RIG-I overexpressing cells had a higher proliferation rate than RIG-I knockdown cells. Moreover, the knockdown of RIG-I slowed migration and invasion rates, whereas the overexpression of RIG-I accelerated migration and invasion rates. RIG-I overexpression induced radioresistance and G2/M phase arrest and reduced DNA damage after exposure to ionizing radiations compared with controls; however, it silenced the RIG-I enhanced radiosensitivity and DNA damage, and reduced the G2/M phase arrest. RNA sequencing revealed that the downstream genes DUSP6 and RIG-I had the same biological function; silencing DUSP6 can reduce the radioresistance caused by the overexpression of RIG-I. RIG-I knockdown depleted tumor growth in vivo, and radiation exposure effectively delayed the growth of xenograft tumors compared with the control group. RIG-I enhances the progression and radioresistance of ESCC; therefore, it may be a new potential target for ESCC-targeted therapy.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Animais , Humanos , Camundongos , Carcinogênese/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Fosfatase 6 de Especificidade Dupla/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/radioterapia , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/genética , Regulação Neoplásica da Expressão Gênica , Camundongos Nus , Receptores do Ácido Retinoico/metabolismo
18.
BMC Plant Biol ; 22(1): 328, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35799118

RESUMO

BACKGROUND: Flowering time is an important agronomic trait of crops and significantly affects plant adaptation and seed production. Flowering time varies greatly among maize (Zea mays) inbred lines, but the genetic basis of this variation is not well understood. Here, we report the comprehensive genetic architecture of six flowering time-related traits using a recombinant inbred line (RIL) population obtained from a cross between two maize genotypes, B73 and Abe2, and combined with genome-wide association studies to identify candidate genes that affect flowering time. RESULTS: Our results indicate that these six traits showed extensive phenotypic variation and high heritability in the RIL population. The flowering time of this RIL population showed little correlation with the leaf number under different environmental conditions. A genetic linkage map was constructed by 10,114 polymorphic markers covering the whole maize genome, which was applied to QTL mapping for these traits, and identified a total of 82 QTLs that contain 13 flowering genes. Furthermore, a combined genome-wide association study and linkage mapping analysis revealed 17 new candidate genes associated with flowering time. CONCLUSIONS: In the present study, by using genetic mapping and GWAS approaches with the RIL population, we revealed a list of genomic regions and candidate genes that were significantly associated with flowering time. This work provides an important resource for the breeding of flowering time traits in maize.


Assuntos
Estudo de Associação Genômica Ampla , Zea mays , Mapeamento Cromossômico/métodos , Ligação Genética , Estudo de Associação Genômica Ampla/métodos , Fenótipo , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Zea mays/genética
19.
Acc Chem Res ; 54(22): 4131-4141, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34726895

RESUMO

Direct dynamics simulations of chemical reactions typically require the selection of a method for generating the potential energy surfaces and a method for the dynamical propagation of the nuclei on these surfaces. The nuclear-electronic orbital (NEO) framework avoids this Born-Oppenheimer separation by treating specified nuclei on the same level as the electrons with wave function methods or density functional theory (DFT). The NEO approach is particularly applicable to proton, hydride, and proton-coupled electron transfer reactions, where the transferring proton(s) and all electrons are treated quantum mechanically. In this manner, the zero-point energy, density delocalization, and anharmonicity of the transferring protons are inherently and efficiently included in the energies, optimized geometries, and dynamics.This Account describes how various NEO methods can be used for direct dynamics simulations on electron-proton vibronic surfaces. The strengths and limitations of these approaches are discussed, and illustrative examples are presented. The NEO-DFT method can be used to simulate chemical reactions on the ground state vibronic surface, as illustrated by the application to hydride transfer in C4H9+. The NEO multistate DFT (NEO-MSDFT) method is useful for simulating ground state reactions in which the proton density becomes bilobal during the dynamics, a characteristic of hydrogen tunneling, as illustrated by proton transfer in malonaldehyde. The NEO time-dependent DFT (NEO-TDDFT) method produces excited electronic, vibrational, and vibronic surfaces. The application of linear-response NEO-TDDFT to H2 and H3+, as well as the partially and fully deuterated counterparts, shows that this approach produces accurate fundamental vibrational excitation energies when all nuclei and all electrons are treated quantum mechanically. Moreover, when only specified nuclei are treated quantum mechanically, this approach can be used to optimize geometries on excited state vibronic surfaces, as illustrated by photoinduced single and double proton transfer systems, and to conduct adiabatic dynamics on these surfaces. The real-time NEO-TDDFT method provides an alternative approach for simulating nonequilibrium nuclear-electronic dynamics of such systems. These various NEO methods can be combined with nonadiabatic dynamics methods such as Ehrenfest and surface hopping dynamics to include the nonadiabatic effects between the quantum and classical subsystems. The real-time NEO-TDDFT Ehrenfest dynamics simulation of excited state intramolecular proton transfer in o-hydroxybenzaldehyde illustrates the power of this type of combined approach. The field of multicomponent quantum chemistry is in the early stages, and the methods discussed herein provide the foundation for a wide range of promising future directions to be explored. An appealing future direction is the expansion of the real-time NEO-TDDFT method to describe the dynamics of all nuclei and electrons on the same level. Direct dynamics simulations using NEO wave function methods such as equation-of-motion coupled cluster or multiconfigurational approaches are also attractive but computationally expensive options. The further development of NEO direct dynamics methods will enable the simulation of the nuclear-electronic dynamics for a vast array of chemical and biological processes that extend beyond the Born-Oppenheimer approximation.

20.
Cell Mol Biol (Noisy-le-grand) ; 68(1): 20-25, 2022 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-35809332

RESUMO

MicroRNAs (miRNAs/miRs) are crucial regulatory molecules that act as the most significantly downregulated microRNAs in hepatocellular carcinoma (HCC). PTK2b/Pyk2 is a non-receptor protein tyrosine kinase, which plays an important role in the development and metastasis of cancer. In this study, we explored the expression level and functional relationship between MicroRNA-214 (miR-214) and PTK2b/ Pyk2 in liver cancer cells. For this purpose, we analyzed the expression of miR-214 and PTK2b/Pyk2 in 38 cases of HCC and paired non-neoplastic tissue specimens using real-time PCR. MTT, cell cycle and construct recombinant plasmids analysis were used to explore the effects of miR-214 and PTK2b/Pyk2 on liver cancer cell proliferation. Results showed that the expression level of mir-214 in liver cancer tissues and liver cancer cell lines was significantly lower than that in normal tissues and cells, while the expression of PTK2b/Pyk2 was significantly increased. The overexpression of mir-214 or inhibition PTK2b/Pyk2 inhibited the proliferation of HCC cells. This research showed that mir-214 has an inhibitory effect on liver cancer through the expression of PTK2b/Pyk2.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Quinase 2 de Adesão Focal/genética , Quinase 2 de Adesão Focal/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo
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