Schlagwort: DNA
Verkleinern, entfernen und verändern: IPK-Team „schneidet“ Weizen-Chromosomen zurecht
Einem Forschungsteam des Leibniz-Instituts für Pflanzengenetik und Kulturpflanzenforschung (IPK) ist es erstmals gelungen, Chromosomen in Pflanzen mit großem Erbgut wie Weizen gezielt zu verkleinern oder sogar vollständig zu entfernen. Dazu setzten die Forscherinnen und Forscher mit der Genschere CRISPR/Cas an sich wiederholenden Abschnitten der DNA an. Die Ergebnisse der Studie, die heute im Fachmagazin „Plant Communications“ veröffentlicht worden sind, können die Züchtungsprozesse erheblich beschleunigen. Quelle: IDW Informationsdienst Wissenschaft Hier jetzt das aktuell Außergewöhnliche auswählen …
Anabaena lernt einen neuen Trick: Cyanobakterien überraschen Forschende mit evolutionärem Wandel
Photosynthetische Bakterien spielten eine entscheidende Rolle bei der Entwicklung unserer Erde. So produzierten Cyanobakterien beispielsweise Sauerstoff und ermöglichten dadurch komplexes Leben. Forschende am Institute of Science and Technology Austria (ISTA) präsentieren nun ein „Evolutions-Update“ der kleinen grünen Mikroorganismen: ein Protein-System, das im Laufe der Zeit seine Aufgabe verändert hat – von der Trennung der DNA hin zur Formgebung der Zelle. Die in Science veröffentlichte Studie zeigt, wie sich solche Proteinsysteme weiterentwickelten und so zur Entstehung der Multizellularität bei Cyanobakterien beitrugen. Quelle: IDW Informationsdienst Wissenschaft Hier jetzt das aktuell Außergewöhnliche auswählen …
Anabaena learns a new trick: Cyanobacteria surprise scientists with evolutionary shift
Photosynthetic bacteria helped shape Planet Earth. Among them are cyanobacteria that produced the oxygen in our atmosphere and made complex life possible, captivating scientists for decades. Now, researchers at the Institute of Science and Technology Austria (ISTA) report a surprising new discovery—a system thought to separate DNA has developed to sculpt the shape of the cell in cyanobacteria instead. The results, published in Science, shed light on how protein systems evolve and how multicellularity emerged in this type of ecologically essential bacteria. Quelle: IDW Informationsdienst Wissenschaft Hier jetzt das aktuell Außergewöhnliche auswählen …
Aging in fast motion: Short-lived fish offer new insights into the aging immune system
Aging causes the immune system to become less effective, increasing susceptibility to infections and age-related diseases. Researchers at the Leibniz Institute on Aging have created a comprehensive molecular and cellular map of immune aging in a vertebrate using the short-lived turquoise killifish. Using a multi-omics approach, they identified key features of immune aging, including chronic inflammation, DNA damage in progenitor cells, and remodeling of the hematopoietic organ. The study shows that important aspects of immune aging are evolutionarily conserved. This makes the killifish particularly well suited for studying the mechanisms of immune aging and testing potential interventions. Quelle: IDW Informationsdienst…
A global assessment of cancer genomic alterations in epigenetic mechanisms
Muhammad A Shah, Emily L Denton, Cheryl H Arrowsmith, Mathieu Lupien and Matthieu Schapira Abstract Background The notion that epigenetic mechanisms may be central to cancer initiation and progression is supported by recent next-generation sequencing efforts revealing that genes involved in chromatin-mediated signaling are recurrently mutated in cancer patients. Results Here, we analyze mutational and transcriptional profiles from TCGA and the ICGC across a collection 441 chromatin factors and histones. Chromatin factors essential for rapid replication are frequently overexpressed, and those that maintain genome stability frequently mutated. We identify novel mutation hotspots such as K36M in histone H3.1, and uncover…
A Mitochondrial Paradigm of Metabolic and Degenerative Diseases, Aging, and Cancer: A Dawn for Evolutionary Medicine
Progressive increase in mtDNA 3243A>G heteroplasmy causes abrupt transcriptional reprogramming Wallace hypothesized mitochondrial dysfunction as a central role in a wide range of age-related disorders and various forms of cancer. Steadily rising increases in mitochondrial DNA mutations cause abrupt shifts in diseases. Discrete changes in nuclear gene expression in response to small increases in DNA mutant level are analogous to the phase shifts that is well known in physics: As heat is added, the ice abruptly turns to water or with more heat abruptly to steam. Therefore, a quantitative change that is an increasing proportion of mitochondrial DNA mutation results…
Variation in cancer risk among tissues can be explained by the number of stem cell divisions
Tomasetti and Vogelstein show that the lifetime risk of cancers of many different types is strongly correlated with the total number of divisions of the normal self-renewing cells maintaining that tissue’s homeostasis. These results suggest that only a third of the variation in cancer risk among tissues is attributable to environmental factors or inherited predispositions. The majority is due to bad luck, that is, random mutations arising during DNA replication in normal, noncancerous stem cells. Tomasetti C, Vogelstein B (2015): Variation in cancer risk among tissues can be explained by the number of stem cell divisions. Science 2 January 2015:…
Quantum entanglement between the electron clouds of nucleic acids in DNA
Rieper, Anders and Vedral modelled the electron clouds of nucleic acids in a single strand of DNA as a chain of coupled quantum harmonic oscillators with dipole-dipole interaction between nearest neighbours. As a main result, the entanglement contained in the chain coincides with the binding energy of the molecule. Derived in the limit of long distances and periodic potentials analytic expressions linking the entanglement witnesses to the energy reduction due to the quantum entanglement in the electron clouds. Rieper E, Anders J, Vedral V (2011) Quantum entanglement between the electron clouds of nucleic acids in DNA. arxiv.org/abs/1006.4053
Three-dimensional super-resolution microscopy of the inactive X chromosome territory reveals a collapse of its active nuclear compartment harboring distinct Xist RNA foci
Daniel Smeets, Yolanda Markaki, Volker J Schmid, Felix Kraus, Anna Tattermusch, Andrea Cerase, Michael Sterr, Susanne Fiedler, Justin Demmerle, Jens Popken, Heinrich Leonhardt, Neil Brockdorff, Thomas Cremer1, Lothar Schermelleh and Marion Cremer Abstract Background A Xist RNA decorated Barr body is the structural hallmark of the compacted inactive X territory in female mammals. Using super-resolution three-dimensional structured illumination microscopy (3D-SIM) and quantitative image analysis, we compared its ultrastructure with active chromosome territories (CTs) in human and mouse somatic cells, and explored the spatio-temporal process of Barr body formation at onset of inactivation in early differentiating mouse embryonic stem cells (ESCs)….
Forscher des HIPS und des HZI finden neues Antibiotikum gegen gram-negative Bakterien
Die Erreger von Infektionserkrankungen Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumanii und Pseudomonas aeruginosa haben zwei große Gemeinsamkeiten: Sie gehören zu den sogenannten gram-negativen Bakterien und sind in Krankenhäusern besonders gefürchtet. Wissenschaftler des Helmholtz-Instituts für Pharmazeutische Forschung Saarland (HIPS) und des Helmholtz-Zentrums für Infektionsforschung (HZI) in Braunschweig haben nun ein potenzielles neues Antibiotikum entdeckt, das gegen diese schwer zu bekämpfenden Bakterien wirkt. Ihre Ergebnisse veröffentlichten die Forscher im renommierten Journal Angewandte Chemie International Edition. Immer mehr Keime entwickeln Resistenzen gegen Antibiotika, sodass diese einstigen Wunderwaffen ihre Wirkungskraft verlieren. Vor allem in Krankenhäusern stellt die steigende Anzahl resistenter Keime das Personal vor…