36 research outputs found

    Evaluation of interspecific DNA variability in poplars using AFLP and SSR markers

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    The objective of this paper was to examine interspecific DNA variation in poplars using AFLP and SSR markers. The AFLP and SSR markers polymorphism and its power of discrimination were determinedwithin 13 genotypes of different genetic background (clones, cultivars, hybrids) of two sections (Aigeiros and Tacamahaca) of genus Populus. Twelve sets of PTR and four sets of WPMS microsatellite primers as well as 6 AFLP primer combinations were used in this study. SSR and AFLP markers revealed high power of discrimination, 0.81 and 0.92 respectively. Results obtained using SSR data showed a clear separation of three major clusters, while four major clusters were obtained using AFLP data. Both markers crearly separated two distinct clusters, one included Populus nigra and the other Populus deltoides genotypes. According to both markers, different genetic background were revealed between two clones of Populus trichocarpa. When evaluating polymorphisms within genotypes ofinterest, microsatellite and AFLP DNA markers proved to be a useful tool for distinguishing genetic background of tree clones, cultivars and hybrid genotypes thus grouping them according to their genetic dissimilarity. The results presented in this study could be of significant interest in poplarbreeding programs and could also be used as a valuable annex in new bred clones registration process

    Cytogenomic Profile of Uterine Leiomyoma: In Vivo vs. In Vitro Comparison

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    We performed a comparative cytogenomic analysis of cultured and uncultured uterine leiomyoma (UL) samples. The experimental approach included karyotyping, aCGH, verification of the detected chromosomal abnormalities by metaphase and interphase FISH, MED12 mutation analysis and telomere measurement by Q-FISH. An abnormal karyotype was detected in 12 out of 32 cultured UL samples. In five karyotypically abnormal ULs, MED12 mutations were found. The chromosomal abnormalities in ULs were present mostly by complex rearrangements, including chromothripsis. In both karyotypically normal and abnormal ULs, telomeres were ~40% shorter than in the corresponding myometrium, being possibly prerequisite to chromosomal rearrangements. The uncultured samples of six karyotypically abnormal ULs were checked for the detected chromosomal abnormalities through interphase FISH with individually designed DNA probe sets. All chromosomal abnormalities detected in cultured ULs were found in corresponding uncultured samples. In all tumors, clonal spectra were present by the karyotypically abnormal cell clone/clones which coexisted with karyotypically normal ones, suggesting that chromosomal abnormalities acted as drivers, rather than triggers, of the neoplastic process. In vitro propagation did not cause any changes in the spectrum of the cell clones, but altered their ratio compared to uncultured sample. The alterations were unique for every UL. Compared to its uncultured counterpart, the frequency of chromosomally abnormal cells in the cultured sample was higher in some ULs and lower in others. To summarize, ULs are characterized by both inter- and intratumor genetic heterogeneity. Regardless of its MED12 status, a tumor may be comprised of clones with and without chromosomal abnormalities. In contrast to the clonal spectrum, which is unique and constant for each UL, the clonal frequency demonstrates up or down shifts under in vitro conditions, most probably determined by the unequal ability of cells with different genetic aberrations to exist outside the body

    Emerging Roles of PAR-1 and PAFR in Melanoma Metastasis

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    Melanoma growth, angiogenesis and metastatic progression are strongly promoted by the inflammatory tumor microenvironment due to high levels of cytokine and chemokine secretion by the recruited inflammatory and stromal cells. In addition, platelets and molecular components of procoagulant pathways have been recently emerging as critical players of tumor growth and metastasis. In particular, thrombin, through the activity of its receptor protease-activated receptor-1 (PAR-1), regulates tumor cell adhesion to platelets and endothelial cells, stimulates tumor angiogenesis, and promotes tumor growth and metastasis. Notably, in many tumor types including melanoma, PAR-1 expression directly correlates with their metastatic phenotype and is directly responsible for the expression of interleukin-8, matrix metalloproteinase-2 (MMP-2), vascular endothelial growth factor, platelet-derived growth factor, and integrins. Another proinflammatory receptor–ligand pair, platelet-activating factor (PAF) and its receptor (PAFR), have been shown to act as important modulators of tumor cell adhesion to endothelial cells, angiogenesis, tumor growth and metastasis. PAF is a bioactive lipid produced by a variety of cells from membrane glycerophospholipids in the same reaction that releases arachidonic acid, and can be secreted by platelets, inflammatory cells, keratinocytes and endothelial cells. We have demonstrated that in metastatic melanoma cells, PAF stimulates the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB) and activating transcription factor 1 (ATF-1), which results in overexpression of MMP-2 and membrane type 1-MMP (membrane type 1-MMP). Since only metastatic melanoma cells overexpress CREB/ATF-1, we propose that metastatic melanoma cells are better equipped than their non-metastatic counterparts to respond to PAF within the tumor microenvironment. The evidence supporting the hypothesis that the two G-protein coupled receptors, PAR-1 and PAFR, contribute to the acquisition of the metastatic phenotype of melanoma is presented and discussed

    Origin and spread of human mitochondrial DNA haplogroup U7

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    Human mitochondrial DNA haplogroup U is among the initial maternal founders in Southwest Asia and Europe and one that best indicates matrilineal genetic continuity between late Pleistocene hunter-gatherer groups and present-day populations of Europe. While most haplogroup U subclades are older than 30 thousand years, the comparatively recent coalescence time of the extant variation of haplogroup U7 (~16–19 thousand years ago) suggests that its current distribution is the consequence of more recent dispersal events, despite its wide geographical range across Europe, the Near East and South Asia. Here we report 267 new U7 mitogenomes that – analysed alongside 100 published ones – enable us to discern at least two distinct temporal phases of dispersal, both of which most likely emanated from the Near East. The earlier one began prior to the Holocene (~11.5 thousand years ago) towards South Asia, while the later dispersal took place more recently towards Mediterranean Europe during the Neolithic (~8 thousand years ago). These findings imply that the carriers of haplogroup U7 spread to South Asia and Europe before the suggested Bronze Age expansion of Indo-European languages from the Pontic-Caspian Steppe region

    CREB Inhibits AP-2α Expression to Regulate the Malignant Phenotype of Melanoma

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    The loss of AP-2alpha and increased activity of cAMP-responsive element binding (CREB) protein are two hallmarks of malignant progression of cutaneous melanoma. However, the molecular mechanism responsible for the loss of AP-2alpha during melanoma progression remains unknown.Herein, we demonstrate that both inhibition of PKA-dependent CREB phosphorylation, as well as silencing of CREB expression by shRNA, restored AP-2alpha protein expression in two metastatic melanoma cell lines. Moreover, rescue of CREB expression in CREB-silenced cell lines downregulates expression of AP-2alpha. Loss of AP-2alpha expression in metastatic melanoma occurs via a dual mechanism involving binding of CREB to the AP-2alpha promoter and CREB-induced overexpression of another oncogenic transcription factor, E2F-1. Upregulation of AP-2alpha expression following CREB silencing increases endogenous p21(Waf1) and decreases MCAM/MUC18, both known to be downstream target genes of AP-2alpha involved in melanoma progression.Since AP-2alpha regulates several genes associated with the metastatic potential of melanoma including c-KIT, VEGF, PAR-1, MCAM/MUC18, and p21(Waf1), our data identified CREB as a major regulator of the malignant melanoma phenotype

    Unveiling the excited state energy transfer pathways in peridinin-chlorophyll α-protein by ultrafast multi-pulse transient absorption spectroscopy

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    Time-resolved multi-pulse methods were applied to investigate the excited state dynamics, the interstate couplings, and the excited state energy transfer pathways between the light-harvesting pigments in peridinin-chlorophyll a-protein (PCP). The utilized pump-dump-probe techniques are based on perturbation of the regular PCP energy transfer pathway. The PCP complexes were initially excited with an ultrashort pulse, resonant to the S₀ → S₂ transition of the carotenoid peridinin. A portion of the peridinin-based emissive intramolecular charge transfer (ICT) state was then depopulated by applying an ultrashort NIR pulse that perturbed the interaction between S₁ and ICT states and the energy flow from the carotenoids to the chlorophylls. The presented data indicate that the peridinin S₁ and ICT states are spectrally distinct and coexist in an excited state equilibrium in the PCP complex. Moreover, numeric analysis of the experimental data asserts ICT → Chl-α as the main energy transfer pathway in the photoexcited PCP systems.11 page(s

    Ontological description of applied tasks and related meteorological and climate data collections

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    The use of the OWL-ontology of climate information resources on the web-GIS of the Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences (IMCES SB RAS) for building an A-box of knowledge base used in an intelligent decision support system (IDSS) is considered in this work. A mathematical model is described, which is used for solution of the task of water freezing and ice melting on the Ob’ river. An example is given of the reduction problem solution with ontological description of the related input and output data of the task

    Ontological description of applied tasks and related meteorological and climate data collections

    No full text
    The use of the OWL-ontology of climate information resources on the web-GIS of the Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences (IMCES SB RAS) for building an A-box of knowledge base used in an intelligent decision support system (IDSS) is considered in this work. A mathematical model is described, which is used for solution of the task of water freezing and ice melting on the Ob’ river. An example is given of the reduction problem solution with ontological description of the related input and output data of the task
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