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1.
Neuroreport ; 31(1): 1-8, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31688420

RESUMO

Hyperactivity of the hypothalamic-pituitary-adrenal axis and impairment of the central corticotropin-releasing factor system are factors in the pathogenesis of depression. Though several antagonists of the corticotropin-releasing factor 1 receptor were effective in the recognized behavioral tests for antidepressant activity, there is still little information on the potential interactions between corticotropin-releasing factor 1 receptor inhibitors and conventional antidepressant therapy. The aim of our study was to assess the influence of CP154526, a corticotropin-releasing factor 1 receptor blocker, which presented some signs of depression. Our results revealed that CP154526 (5 and 10 mg/kg) or fluoxetine (10 mg/kg) treatment notably improved the sucrose consumption, produced anti-depressive-like behavior in open-field test, as well as immobility time in forced swimming test. The levels of interleukin-6, interleukin-1ß, tumor necrosis factor-α, and corticotropin-releasing hormone concentration in the serum were inhibited effectively by CP154526 or fluoxetine administration. Real-time quantitative PCR and western blot analysis showed the upregulated levels of brain-derived neurotrophic factor and growth associated protein 43 (GAP43) in the hypothalamus of the rats exposed to chronic unpredictable mild stress (CUMS), while different degrees of downregulation in their expression were detected after CP154526 (5 and 10 mg/kg) or fluoxetine (10 mg/kg) treatment, respectively. Thus, our data demonstrated that CP154526 exhibited antidepressant effect in CUMS rats, which might be mediated by decreasing the brain-derived neurotrophic factor and GAP43 expression in the hypothalamus.

2.
Science ; 366(6464): 475-479, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31649196

RESUMO

Ferroelectrics are usually inflexible oxides that undergo brittle deformation. We synthesized freestanding single-crystalline ferroelectric barium titanate (BaTiO3) membranes with a damage-free lifting-off process. Our BaTiO3 membranes can undergo a ~180° folding during an in situ bending test, demonstrating a super-elasticity and ultraflexibility. We found that the origin of the super-elasticity was from the dynamic evolution of ferroelectric nanodomains. High stresses modulate the energy landscape markedly and allow the dipoles to rotate continuously between the a and c nanodomains. A continuous transition zone is formed to accommodate the variant strain and avoid high mismatch stress that usually causes fracture. The phenomenon should be possible in other ferroelectrics systems through domain engineering. The ultraflexible epitaxial ferroelectric membranes could enable many applications such as flexible sensors, memories, and electronic skins.

3.
Neuroreport ; 30(13): 893-900, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31373969

RESUMO

Ginsenoside (GS Rg1), which has neuroprotection and anti-inflammation activities, is the main active ingredient of Radix Ginseng. However, its antidepressant-like effect in rats remains unclear. Our study was conducted to investigate whether GS Rg1 confers an antidepressant effect in rats exposed to a chronic unpredictable mild stress model of depression and to explore its possible mechanisms. Our results revealed that GS Rg1 treatments for 3 weeks alleviated the depression-related behaviors of chronic unpredictable mild stress-exposed rats, as indicated by increasing sucrose preference, improving locomotor activity and shortening immobile time in both the forced swimming tests and tail suspension tests. And these ameliorative effects of GS Rg1 treatment were involved with regulating chronic unpredictable mild stress-induced pro-inflammatory cytokine interleukin beta (IL-1ß) related neuro-inflammation. In addition, we further found that GS Rg1 reversed chronic unpredictable mild stress-induced IL-1ß elevation, possibly by inhibiting nuclear factor kappa B pathway activation and regulating nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 inflammasome expression. In short, our results suggested that GS Rg1 exerted a potential antidepressant-like effect in chronic unpredictable mild stress rat model of depression, which may provide an insight into the potential of GS Rg1 in therapeutic implications for depression.

4.
Zhongguo Zhong Yao Za Zhi ; 44(10): 2020-2025, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355555

RESUMO

To further study the mechanism of sprout tumble caused by drought,drought stress was simulating with 30% PEG 6000,physiological,and then the morphological changes of Pinellia ternata cells at different treatment time were detected. The results indicated that,along with the period of drought stress continued,the contents of chlorophyll and water potential were decreased,relative electrical conductivity,contents of soluble sugar and MDA increased. Sprout tumble of P. ternata first occurred on the fourth day during drought stress,large scale of sprout tumble appeared on the eighth day with about 73% of tumble rate. The nuclei exposed to drought stress for 2 days were flattened,lobed,invalidated or irregular in shape and significant showed the apoptotic morphological characteristics. Adenylate transferase( ANT) gene expressions were inhibited by drought,with the rapid increase of Caspase-3 enzyme activity,the cell death rate increased. All this proves that the essence of sprout tumble caused by drought is programmed cell death,which may be a self dormancy protection mechanism of P. ternata against adverse environment.


Assuntos
Apoptose , Secas , Pinellia/citologia , Estresse Fisiológico
5.
World Neurosurg ; 129: e650-e656, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31158546

RESUMO

BACKGROUND: Hyperactive dysfunction syndrome (HDS) of the cranial nerves, such as trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN), is commonly managed by microsurgical treatment. However, certain patients may present a combination of these syndromes in the neurosurgery department. Here, we aimed to retrospectively assess patients with combined HDS from a single center. METHOD: Of 1275 consecutive patients with HDS treated at our center between 2007 and 2017, 37 patients with combined HDS were enrolled, and their medical and surgical records were analyzed. RESULTS: The patients with combined HDS, accounting for 2.9% of all patients with HDS, included 22 patients with bilateral TN, 5 patients with TN-HFS, 8 patients with TN-GPN, and 2 patients with GPN-HFS. A comparison of patients with single and combined HDS indicated a significant difference in the mean age at initial diagnosis (63.57 vs. 56.18 years, P = 0.000) but no such difference in the sex ratio (0.54 vs. 0.59, P = 0.865) or incidence of hypertension (32.43% vs. 24.56%, P = 0.274). In total, 32 microvascular decompression (MVD) procedures were performed in the 27 patients with combined HDS, and repeated MVD was required in 5 patients with bilateral TN. Of the 27 patients who underwent MVD, 25 (92.6%) experienced clinical cure or obvious alleviation. CONCLUSIONS: Combined HDS involves a group of functional disturbance disorders affecting specific cranial nerves, and it may include TN, HFS, and GPN. In addition to gender and incidence of hypertension, age appeared to be a vital indicator for the development of combined HDS, although this finding was inconsistent in previous studies. MVD appears to be a safe and effective treatment for combined HDS, with a high rate of long-term success.


Assuntos
Doenças dos Nervos Cranianos/cirurgia , Nervos Cranianos/cirurgia , Cirurgia de Descompressão Microvascular/métodos , Procedimentos Neurocirúrgicos/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
6.
Front Physiol ; 10: 164, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30894818

RESUMO

Scopoletin is a promising acaricidal botanical natural compound against Tetranychus cinnabarinus, and its acaricidal mechanism maybe involve calcium overload according to our previous study. To seek potential candidate target genes of calcium overload induced by scopoletin in T. cinnabarinus, RNA-seq was utilized to detect changes in transcription levels. 24 and 48 h after treatment, 70 and 102 differentially expressed genes were obtained, respectively. Target genes included 3 signal transduction genes, 4 cell apoptosis genes, 4 energy metabolism genes, and 2 transcription factor genes. The role of 3 calcium signaling pathway-related genes, namely, G-protein-coupled neuropeptide receptor, Bcl-2 protein and guanylate kinase (designated TcGPCR, TcBAG, and TcGUK, respectively) in the calcium overload were investigated in this study. RT-qPCR detection showed that scopoletin treatment upregulated the expression level of TcGPCR and downregulated the expression level of TcBAG and TcGUK. The result of RNAi indicated that downregulation of TcGPCR decreased susceptibility to scopoletin, and downregulation of TcBAG and TcGUK enhanced susceptibility to scopoletin. Functional expression in Chinese hamster ovary cells showed that scopoletin induced a significant increase in intracellular free calcium [Ca2+]i levels by activating TcGPCR. These results demonstrated that the acaricidal mechanism of scopoletin was via disrupting intracellular Ca2+ homeostasis and calcium signaling pathway mediated by GPCR, BAG, and GUK.

7.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(5): 454-456, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31894680

RESUMO

OBJECTIVE: To study the effects of cold exposure on estrous cycle of female C57BL/6 mice. METHODS: Twelve healthy female C57BL/6 mice were randomly divided into two groups: control group and cold exposure group, 6 in each group. Cold exposure group was exposed to 4℃, 4 h per day, while control group stayed in normal conditions. Vaginal smears were used to observe the estrous cycle. After 2 weeks, blood and uteri were collected from each mouse after anesthetized and weighted. Serum levels of estradiol(E2), follicle-stimulating hormone(FSH), luteinizing hormone(LH), prolactin(Prl) and progesterone(P) were determined by using mouse ELISA kits. The uterus and ovary pathological slices were prepared to observe the structural changes. RESULTS: Compared with the control group, body weight gain showed no significant differences (P>0.05). The cold group had significant lower coefficients of uterus and the diestrus phase was significantly increased after cold exposure (P<0.01). Serum level of FSH in cold group was higher and Prl was lower significantly (P<0.01). Pathological examination of uterus and ovary showed that uterine glands of cold group were expanded and the amount of follicles was decreased significantly. CONCLUSION: Cold exposure might increase mouse estrous cycle and affect their reproductive function.


Assuntos
Temperatura Baixa , Ciclo Estral , Hormônio Luteinizante , Animais , Diestro , Exposição Ambiental , Estradiol/sangue , Ciclo Estral/fisiologia , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Camundongos , Camundongos Endogâmicos C57BL , Progesterona/sangue , Distribuição Aleatória
8.
Int J Mol Sci ; 19(9)2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30200389

RESUMO

Self-incompatibility (SI) is a type of reproductive barrier within plant species and is one of the mechanisms for the formation and maintenance of the high diversity and adaptation of angiosperm species. Approximately 40% of flowering plants are SI species, while only 10% of orchid species are self-incompatible. Intriguingly, as one of the largest genera in Orchidaceae, 72% of Dendrobium species are self-incompatible, accounting for nearly half of the reported SI species in orchids, suggesting that SI contributes to the high diversity of orchid species. However, few studies investigating SI in Dendrobium have been published. This study aimed to address the following questions: (1) How many SI phenotypes are in Dendrobium, and what are they? (2) What is their distribution pattern in the Dendrobium phylogenetic tree? We investigated the flowering time, the capsule set rate, and the pollen tube growth from the representative species of Dendrobium after artificial pollination and analysed their distribution in the Asian Dendrobium clade phylogenetic tree. The number of SI phenotypes exceeded our expectations. The SI type of Dendrobium chrysanthum was the primary type in the Dendrobium SI species. We speculate that there are many different SI determinants in Dendrobium that have evolved recently and might be specific to Dendrobium or Orchidaceae. Overall, this work provides new insights and a comprehensive understanding of Dendrobium SI.


Assuntos
Evolução Biológica , Dendrobium/classificação , Dendrobium/genética , Autoincompatibilidade em Angiospermas/genética , Flores/genética , Flores/crescimento & desenvolvimento , Frutas/genética , Frutas/crescimento & desenvolvimento , Fenótipo , Filogenia , Tubo Polínico/genética , Tubo Polínico/crescimento & desenvolvimento , Polinização , Sementes/genética , Fatores de Tempo
9.
Sci Rep ; 8(1): 11640, 2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30076357

RESUMO

Deceptive pollination is key to the species richness of Orchidaceae. However, the genetic basis of species diversification is still under study. Section Trigonopedia is a monophyletic clade of genus Cypripedium distributed in the southwest of China. The species of this section are pollinated by different flies. Pollinator differentiation makes section Trigonopedia an ideal group for studying the genetic basis underlying species diversification. Here, we sequenced the transcriptomes of eight species of the genus Cypripedium, including six co-flowering species of section Trigonopedia and two species outside this section as an outgroup. We reconstructed the phylogeny of the section with the combined 1572 single-copy genes extracted from the eight species and produced a highly resolved tree of the section. Furthermore, we combined substitution rate estimation and differential expression analysis to identify candidate genes, including genes related to floral scent synthesis and environmental adaptation, involved in species differentiation. Field investigations showed that these species have adapted to different habitats. We propose that the species diversification in this section is initiated by floral scent differentiation, followed by habitat differentiation, finally leading to speciation. This study sheds novel light on the diversification of closely related orchid species in the Qinghai-Tibetan region.


Assuntos
Adaptação Fisiológica/genética , Orchidaceae/genética , Polinização/genética , Transcriptoma/genética , Animais , Dípteros/genética , Dípteros/fisiologia , Flores/genética , Flores/crescimento & desenvolvimento , Orchidaceae/crescimento & desenvolvimento , Especificidade da Espécie
11.
Angew Chem Int Ed Engl ; 57(41): 13528-13532, 2018 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-30144271

RESUMO

We describe an approach to N-tosyl 1,3-amino alcohols that consists of a diastereoselective aziridination reaction of acyclic allylic alcohols and an unprecedented regioselective hydrosilylation of α-hydroxy aziridines. The products contain up to three contiguous stereocenters. Computational studies outline key aspects of the aziridination mechanism, which is different and more intricate than anticipated.

12.
Thorac Cancer ; 9(11): 1361-1365, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30144287

RESUMO

BACKGROUND: Elderly patients are under-represented in studies of pure ground-glass opacity (pGGO) nodules; thus, this study analyzed the growth pattern and clinical outcomes of pGGO nodules in the elderly in order to help make treatment decisions. METHODS: We retrospectively reviewed patients aged over 60 years with screening-detected and pathologically confirmed growing focal pGGO nodules. RESULTS: During the study period, 858 subjects had undergone at least three low-dose computed tomography scans in our center. Twenty patients were treated for growing focal pGGO nodules. The median age at detection was 66 years (range: 60-80). The median time to an increase of at least 2 mm was 348 days (range: 98-1527) and to develop a solid portion, 1141 days (range: 480-3010). Seven patients had surgery for increased nodule size, four had surgery immediately after the solid portion appeared, and nine were treated after a median follow-up of 1153 days (range: 240-2342) since the solid portion developed. The median size of the solid component was 8 mm (2-13) before surgery. No recurrence was observed after a median follow-up of 41 months. Pathology revealed adenocarcinoma in situ in five patients, and minimally invasive or invasive adenocarcinoma in the remainder. The appearance of a solid portion was significantly associated with invasive adenocarcinoma compared to increased size alone (100% vs. 44.4%; P = 0.005). CONCLUSIONS: pGGO nodules had an indolent growth pattern and good prognosis in our patient sample, even after the appearance of a solid portion. Therefore, minimally invasive surgery after the development of a solid component may be an option for the elderly.


Assuntos
Adenocarcinoma de Pulmão/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adenocarcinoma de Pulmão/patologia , Idoso , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estudos Retrospectivos
13.
Biomed Pharmacother ; 106: 794-804, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29990873

RESUMO

Leukemia is a hematologic malignancy with poor prognosis in humans and chemotherapy is the main strategy for treating leukemia patients. Novel drugs with better selectivity and lower toxicity are required for the treatment of patients. A novel 3',5'-diprenylated chalcone, (E)-1-(2-hydroxy-4-methoxy-3,5-diprenyl) phenyl-3-(3- pyridinyl)-propene-1-one (C10) is a potential new anti-leukemia agent. In this study, we investigated the molecular mechanisms of the anti-leukemia effects of C10 on different leukemia cells in vitro. C10 showed strong inhibition of proliferation of the human erythroleukemia cell line HEL and human myeloid leukemia cell line K562, and several cell and flow cytometer assays showed that inhibition by C10 was due to the regulation of gene expression or phosphorylation in the apoptosis and autophagy pathways. The results showed that C10 regulated the expression of Bax, c-Myc, Bcl-2, P38/AMPK and ERK 1/2, activated the expression of Caspase-3, -8, and PARP at the protein level in the apoptosis pathway of the two leukemia cell types, and inhibited the expression of erythroleukemia carcinogene Fli-1 in the human erythroleukemia cell line HEL. Additionally,treatment with the compound induced a time-dependent increase in expression of LC 3A/B via inhibiting the AKT-mTOR pathway, which is associated with cell autophagy. Taken together, the above results suggest that the novel synthesized 3',5'-diprenylated chalcone can prevent the growth of leukemia cells by inducing apoptosis and autophagy.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Chalconas/farmacologia , Leucemia Eritroblástica Aguda/tratamento farmacológico , Antineoplásicos/síntese química , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Proliferação de Células/efeitos dos fármacos , Chalconas/síntese química , Chalconas/química , Relação Dose-Resposta a Droga , Regulação Leucêmica da Expressão Gênica , Humanos , Células K562 , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/patologia , Fosforilação , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
14.
Orthop Surg ; 10(2): 160-168, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29767463

RESUMO

OBJECTIVES: As promising alternative to current metallic biomaterials, the porous Mg scaffold with a 3-D open-pore framework has drawn much attention in recent years due to its suitable biodegradation, biocompatibility, and mechanical properties for human bones. This experiment's aim is to study the mechanical properties, biosafety, and osteogenesis of porous Mg-Zn alloy. METHODS: A porous Mg-2Zn-0.3Ca (wt%) alloy was successfully prepared by infiltration casting, and the size of NaCl particles was detected by a laser particle size analyzer. The microstructure of the Mg-2Zn-0.3Ca alloy was characterized by the stereoscopic microscope and Sirion Field emission scanning electron microscope. X-ray computerized tomography scanning (x-CT) was used to create the 3-D image. The degradation rate was measured using the mass loss method and the pH values were determined together. The engineering stress-strain curve, compressive modulus, and yield strength were tested next. The bone marrow stromal cells (BMSC) were cultured in vitro. The CCK-8 method was used to detect the proliferation of the BMSC. Alkaline phosphatase (ALP) and alizarin red staining were used to reflect the differentiation effects. After co-culturing, cell growth on the material's surface was observed by scanning electron microscope (SEM). The cell adhesion was tested by confocal microscopy. RESULTS: The obtained results showed that by using near-spherical NaCl filling particles, the porous Mg alloy formed complete open-cell foam with a very uniform size of pores in the range of 500-600 µm. Benefitting from the small size and uniform distribution of pores, the present porous alloy exhibited a very high porosity, up to 80%, and compressive yield strength up to 6.5 MPa. The degradation test showed that both the pH and the mass loss rate had similar change tendency, with a rapid rise in the early stage for 1-2 day's immersion and subsequently remaining smooth after 3 days. In vitro cytocompatibility trials demonstrated that in comparison with Ti, the porous alloy accelerated proliferation in 1, 3, 5, and 7 days (P < 0.001), and the osteogenic differentiation test showed that the ALP activity in the experimental group was significantly higher (P = 0.017) and has more osteogenesis nodules. Cell adhesion testing showed good osteoconductivity by more BMSC adhesion around the holes. The confocal microscopy results showed that cells in porous Mg-based alloy had better cytoskeletal morphology and were larger in number than in titanium. CONCLUSIONS: These results indicated that this porous Mg-based alloy fabricated by infiltration casting shows great mechanical properties and biocompatibilities, and it has potential as an ideal bone tissue engineering scaffold material for bone regeneration.


Assuntos
Implantes Absorvíveis , Ligas/química , Substitutos Ósseos/química , Materiais Biocompatíveis/química , Fenômenos Biomecânicos , Cálcio , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Técnicas de Cocultura , Humanos , Magnésio , Teste de Materiais/métodos , Células-Tronco Mesenquimais/fisiologia , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Porosidade , Cloreto de Sódio , Tecidos Suporte , Zinco
15.
Insect Sci ; 25(6): 1025-1034, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28485823

RESUMO

The stylet penetration behavior of aphids when feeding on plants is associated with virus acquisition and inoculation. Aphidius gifuensis (Ashmead) is a primary endoparasitoid of Myzus persicae (Sulzer) which is the most efficient vector of plant viruses. Information about the effects of parasitoid on aphid and virus transmission can provide an essential foundation for designing effective biological control strategies. This study aimed to investigate the effects of A. gifuensis on the feeding behavior and potato virus Y (PVY) transmission ability of M. persicae. The results showed that after M. persicae was parasitized by A. gifuensis, the duration of the first probe significantly decreased. Additionally, A. gifuensis exerted remarkable effects on aphid feeding in phloem ingestion. The contribution of the E1 waveform to the phloem phase was significantly higher in all parasitized aphids than in the control group. Although the time of infestation increased for parasitized aphids, the total duration of phloem sap ingestion decreased. Interestingly, the percentage of time M. persicae spent in the xylem and phloem phases only changed significantly on day 5. The percent transmission of PVY by the aphids parasitized on day 5 was lower than that in the control, but no significant differences were detected. The significance of this work is the demonstration that A. gifuensis can impede the feeding behavior of M. persicae, which sheds light on the biological basis of A. gifuensis as a natural enemy, but unfortunately does not provide an immediate solution for disrupting the transmission of PVY.


Assuntos
Afídeos/fisiologia , Afídeos/parasitologia , Comportamento Alimentar , Insetos Vetores/fisiologia , Potyvirus , Animais , Afídeos/virologia
16.
Nature ; 549(7672): 379-383, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28902843

RESUMO

Constituting approximately 10% of flowering plant species, orchids (Orchidaceae) display unique flower morphologies, possess an extraordinary diversity in lifestyle, and have successfully colonized almost every habitat on Earth. Here we report the draft genome sequence of Apostasia shenzhenica, a representative of one of two genera that form a sister lineage to the rest of the Orchidaceae, providing a reference for inferring the genome content and structure of the most recent common ancestor of all extant orchids and improving our understanding of their origins and evolution. In addition, we present transcriptome data for representatives of Vanilloideae, Cypripedioideae and Orchidoideae, and novel third-generation genome data for two species of Epidendroideae, covering all five orchid subfamilies. A. shenzhenica shows clear evidence of a whole-genome duplication, which is shared by all orchids and occurred shortly before their divergence. Comparisons between A. shenzhenica and other orchids and angiosperms also permitted the reconstruction of an ancestral orchid gene toolkit. We identify new gene families, gene family expansions and contractions, and changes within MADS-box gene classes, which control a diverse suite of developmental processes, during orchid evolution. This study sheds new light on the genetic mechanisms underpinning key orchid innovations, including the development of the labellum and gynostemium, pollinia, and seeds without endosperm, as well as the evolution of epiphytism; reveals relationships between the Orchidaceae subfamilies; and helps clarify the evolutionary history of orchids within the angiosperms.


Assuntos
Evolução Molecular , Genoma de Planta/genética , Orchidaceae/genética , Filogenia , Genes de Plantas/genética , Orchidaceae/anatomia & histologia , Orchidaceae/classificação , Transcriptoma
17.
Angew Chem Int Ed Engl ; 56(41): 12654-12657, 2017 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-28833905

RESUMO

Aziridines activated by N-acylation are opened to the higher substituted radical through electron transfer from titanocene(III) complexes in a novel catalytic reaction. This reaction is applicable in conjugate additions, reductions, and cyclizations and suited for the construction of quaternary carbon centers. The concerted mechanism of the ring opening is indicated by DFT calculations.

18.
Front Plant Sci ; 8: 1106, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28690630

RESUMO

Self-incompatibility (SI) is found in approximately 40% of flowering plant species and at least 100 families. Although orchids belong to the largest angiosperm family, only 10% of orchid species present SI and have gametophytic SI (GSI). Furthermore, a majority (72%) of Dendrobium species, which constitute one of the largest Orchidaceae genera, show SI and have GSI. However, nothing is known about the molecular mechanism of GSI. The S-determinants of GSI have been well characterized at the molecular level in Solanaceae, Rosaceae, and Plantaginaceae, which use an S-ribonuclease (S-RNase)-based system. Here, we investigate the hypothesis that Orchidaceae uses a similar S-RNase to those described in Rosaceae, Solanaceae, and Plantaginaceae SI species. In this study, two SI species (Dendrobium longicornu and D. chrysanthum) were identified using fluorescence microscopy. Then, the S-RNase- and SLF-interacting SKP1-like1 (SSK1)-like genes present in their transcriptomes and the genomes of Phalaenopsis equestris, D. catenatum, Vanilla shenzhenica, and Apostasia shenzhenica were investigated. Sequence, phylogenetic, and tissue-specific expression analyses revealed that none of the genes identified was an S-determinant, suggesting that Orchidaceae might have a novel SI mechanism. The results also suggested that RNase-based GSI might have evolved after the split of monocotyledons (monocots) and dicotyledons (dicots) but before the split of Asteridae and Rosidae. This is also the first study to investigate S-RNase-based GSI in monocots. However, studies on gene identification, differential expression, and segregation analyses in controlled crosses are needed to further evaluate the genes with high expression levels in GSI tissues.

19.
Int J Mol Sci ; 18(7)2017 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-28653986

RESUMO

The carmine spider mite, Tetranychus cinnabarinus (Boisduval), is an economically important agricultural pest that is difficult to prevent and control. Scopoletin is a botanical coumarin derivative that targets Ca2+-ATPase to exert a strong acaricidal effect on carmine spider mites. In this study, the full-length cDNA sequence of a plasma membrane Ca2+-ATPase 1 gene (TcPMCA1) was cloned. The sequence contains an open reading frame of 3750 bp and encodes a putative protein of 1249 amino acids. The effects of scopoletin on TcPMCA1 expression were investigated. TcPMCA1 was significantly upregulated after it was exposed to 10%, 30%, and 50% of the lethal concentration of scopoletin. Homology modeling, molecular docking, and three-dimensional quantitative structure-activity relationships were then studied to explore the relationship between scopoletin structure and TcPMCA1-inhibiting activity of scopoletin and other 30 coumarin derivatives. Results showed that scopoletin inserts into the binding cavity and interacts with amino acid residues at the binding site of the TcPMCA1 protein through the driving forces of hydrogen bonds. Furthermore, CoMFA (comparative molecular field analysis)- and CoMSIA (comparative molecular similarity index analysis)-derived models showed that the steric and H-bond fields of these compounds exert important influences on the activities of the coumarin compounds.Notably, the C3, C6, and C7 positions in the skeletal structure of the coumarins are the most suitable active sites. This work provides insights into the mechanism underlying the interaction of scopoletin with TcPMCA1. The present results can improve the understanding on plasma membrane Ca2+-ATPase-mediated (PMCA-mediated) detoxification of scopoletin and coumarin derivatives in T. cinnabarinus, as well as provide valuable information for the design of novel PMCA-inhibiting acaricides.


Assuntos
Acaricidas/toxicidade , ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo , Escopoletina/toxicidade , Tetranychidae/enzimologia , Regulação para Cima/efeitos dos fármacos , Acaricidas/química , Animais , Clonagem Molecular , Regulação da Expressão Gênica/efeitos dos fármacos , Simulação de Acoplamento Molecular , Filogenia , ATPases Transportadoras de Cálcio da Membrana Plasmática/química , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , Relação Quantitativa Estrutura-Atividade , Escopoletina/química , Tetranychidae/efeitos dos fármacos , Tetranychidae/genética
20.
Angew Chem Int Ed Engl ; 56(33): 9719-9722, 2017 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-28608622

RESUMO

Described herein is a novel concept for SN 2 reactions at tertiary carbon centers in epoxides without activation of the leaving group. Quantum chemical calculations show why SN 2 reactions at tertiary carbon centers are proceeding in these systems. The reaction allows flexible synthesis of 1,3-diol building blocks for natural product synthesis with excellent control of the relative and absolute configurations.

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