86 research outputs found

    Phylogenomics and morphological evolution of the mega-diverse genus Artemisia (Asteraceae: Anthemideae): implications for its circumscription and infrageneric taxonomy

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    Background and Aims Artemisia is a mega-diverse genus consisting of ~400 species. Despite its medicinal importance and ecological significance, a well-resolved phylogeny for global Artemisia, a natural generic delimitation and infrageneric taxonomy remain missing, owing to the obstructions from limited taxon sampling and insufficient information on DNA markers. Its morphological characters, such as capitulum, life form and leaf, show marked variations and are widely used in its infrageneric taxonomy. However, their evolution within Artemisia is poorly understood. Here, we aimed to reconstruct a well-resolved phylogeny for global Artemisia via a phylogenomic approach, to infer the evolutionary patterns of its key morphological characters and to update its circumscription and infrageneric taxonomy. Methods We sampled 228 species (258 samples) of Artemisia and its allies from both fresh and herbarium collections, covering all the subgenera and its main geographical areas, and conducted a phylogenomic analysis based on nuclear single nucleotide polymorphisms (SNPs) obtained from genome skimming data. Based on the phylogenetic framework, we inferred the possible evolutionary patterns of six key morphological characters widely used in its previous taxonomy. Key Results The genus Kaschgaria was revealed to be nested in Artemisia with strong support. A well-resolved phylogeny of Artemisia consisting of eight highly supported clades was recovered, two of which were identified for the first time. Most of the previously recognized subgenera were not supported as monophyletic. Evolutionary inferences based on the six morphological characters showed that different states of these characters originated independently more than once. Conclusions The circumscription of Artemisia is enlarged to include the genus Kaschgaria. The morphological characters traditionally used for the infrageneric taxonomy of Artemisia do not match the new phylogenetic tree. They experienced a more complex evolutionary history than previously thought. We propose a revised infrageneric taxonomy of the newly circumscribed Artemisia, with eight recognized subgenera to accommodate the new results.This work was supported by the National Natural Science Foundation of China (grant nos. 31870179, 31570204, 31270237 and J1310002), the International Partnership Program (grant no. 151853KYSB20190027), Sino-Africa Joint Research Center (grant no. SAJC201614), Key technology projects of Jiangxi Province's major scientific and technological research and development project (grant no. 20223AAF01007), Survey of Wildlife Resources in Key Areas of Tibet (grant no. ZL202203601) and National Plant Specimen Resource Center (grant no. E0117G1001) of the Chinese Academy of Sciences, Key Project at Central Government Level: The Ability Establishment of Sustainable Use of Valuable Chinese Medicine Resources (grant no. 2060302) and Project of the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences (grant no. AAAA-A21-121011290024-5).Abstract INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION Conclusions SUPPLEMENTARY DATA FUNDING ACKNOWLEDGEMENTS CONFLICT OF INTEREST LITERATURE CITED Supplementary dat

    Expression of oestrogen receptors, ERα, ERβ, and ERβ variants, in endometrial cancers and evidence that prostaglandin F may play a role in regulating expression of ERα

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    <p>Abstract</p> <p>Background</p> <p>Endometrial cancer is the most common gynaecological malignancy; risk factors include exposure to oestrogens and high body mass index. Expression of enzymes involved in biosynthesis of oestrogens and prostaglandins (PG) is often higher in endometrial cancers when compared with levels detected in normal endometrium. Oestrogens bind one of two receptors (ERα and ERβ) encoded by separate genes. The full-length receptors function as ligand-activated transcription factors; splice variant isoforms of ERβ lacking a ligand-binding domain have also been described. PGs act in an autocrine or paracrine manner by binding to specific G-protein coupled receptors.</p> <p>Methods</p> <p>We compared expression of ERs, progesterone receptor (PR) and cyclooxygenase-2 (COX-2) in stage 1 endometrial adenocarcinomas graded as well (G1), moderately (G2) or poorly (G3) differentiated (n ≥ 10 each group) using qRTPCR, single and double immunohistochemistry. We used endometrial adenocarcinoma cell lines to investigate the impact of PGF2α on expression of ERs and PR.</p> <p>Results</p> <p>Full length ERβ (ERβ1) and two ERβ variants (ERβ2, ERβ5) were expressed in endometrial cancers regardless of grade and the proteins were immunolocalised to the nuclei of cells in both epithelial and stromal compartments. Immunoexpression of COX-2 was most intense in cells that were ERα<sup>neg/low</sup>. Expression of PR in endometrial adenocarcinoma (Ishikawa) cell lines and tissues broadly paralleled that of ERα. Treatment of adenocarcinoma cells with PGF2α reduced expression of ERα but had no impact on ERβ1. Cells incubated with PGF2α were unable to increase expression of PR mRNA when they were incubated with E2.</p> <p>Conclusion</p> <p>We have demonstrated that ERβ5 protein is expressed in stage 1 endometrial adenocarcinomas. Expression of three ERβ variants, including the full-length protein is not grade-dependent and most cells in poorly differentiated cancers are ERβ<sup>pos</sup>/ERα<sup>neg</sup>. We found evidence of a link between COX-2, its product PGF2α, and expression of ERα and PR that sheds new light on the cross talk between steroid and PG signalling pathways in this disease.</p

    HoxA-11 and FOXO1A Cooperate to Regulate Decidual Prolactin Expression: Towards Inferring the Core Transcriptional Regulators of Decidual Genes

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    During the menstrual cycle, the ovarian steroid hormones estrogen and progesterone control a dramatic transcriptional reprogramming of endometrial stromal cells (ESCs) leading to a receptive state for blastocyst implantation and the establishment of pregnancy. A key marker gene of this decidualization process is the prolactin gene. Several transcriptional regulators have been identified that are essential for decidualization of ESCs, including the Hox genes HoxA-10 and HoxA-11, and the forkhead box gene FOXO1A. While previous studies have identified downstream target genes for HoxA-10 and FOXO1A, the role of HoxA-11 in decidualization has not been investigated. Here, we show that HoxA-11 is required for prolactin expression in decidualized ESC. While HoxA-11 alone is a repressor on the decidual prolactin promoter, it turns into an activator when combined with FOXO1A. Conversely, HoxA-10, which has been previously shown to associate with FOXO1A to upregulate decidual IGFBP-1 expression, is unable to upregulate PRL expression when co-expressed with FOXO1A. By co-immunoprecipitation and chromatin immunoprecipitation, we demonstrate physical association of HoxA-11 and FOXO1A, and binding of both factors to an enhancer region (−395 to −148 relative to the PRL transcriptional start site) of the decidual prolactin promoter. Because FOXO1A is induced upon decidualization, it serves to assemble a decidual-specific transcriptional complex including HoxA-11. These data highlight cooperativity between numerous transcription factors to upregulate PRL in differentiating ESC, and suggest that this core set of transcription factors physically and functionally interact to drive the expression of a gene battery upregulated in differentiated ESC. In addition, the functional non-equivalence of HoxA-11 and HoxA-10 with respect to PRL regulation suggests that these transcription factors regulate distinct sets of target genes during decidualization

    Short channel vertical transistors with excellent saturation characteristics

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    The use of a vertical thin film transistor (VTFT) topology in the flat panel active matrix array, opens up a plethora of new high performance applications. The VTFT is small in footprint by virtue of its stacked layer configuration, in which channel lengths can be conveniently scaled down to nanometer regime without having to resort to photolithography as would otherwise be needed when scaling lateral TFTs. More importantly, the VTFT is also fully compatible to the materials and processes used in flat panel technology, takes making it amenable to large area scaling. © 2009 IEEE

    Polymer thin film transistor without surface pretreatment on silicon nitride gate dielectric

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    It is well known that surface modification of the gate dielectric in organic thin film transistors (TFTs) plays an important role in device performance, often giving rise to severalfold improvements in field-effect mobility. This paper reports on solution-processed polymer TFTs with mobilities comparable to high performance counterparts despite the absence of dielectric surface pretreatment. An effective mobility of 0.1 cm2 V s was obtained with poly(2,5-bis(3-dodecylthiophene-2-yl)thieno[3,2-b]thiophene) transistors on silicon nitride gate dielectric. The results indicate that by judicious preparation of the device layers, one can mitigate the need for dielectric surface pretreatment, thereby reducing fabrication complexity without compromising TFT performance. © 2008 American Institute of Physics

    Performance of injection-limited polymer light-emitting diodes

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    The electro-optical characteristics of a polymer light emitting diode (PLED) with a strongly reduced hole injection have been investigated. The device consists of a poly-p-phenylene vinylene semiconductor with a Ag hole injecting contact, which has an injection barrier of about 1 eV. It is observed that the light and current density of such an injection-limited PLED strongly exceed the expected device characteristics. Numerical calculations of the injection-limited PLED show that the enhanced performance can be explained by a very high electric field at the bole injecting contact, due to trapped electrons
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