biologie et génétique
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L'application de l'hybridation fluorescente in situ (FISH) à une cellule d'embryon unique (blastomère) présente des défis particuliers à la fois dans les pratiques et dans l'interprétation du modèle de signal. La cellule de biopsie doit être réparti dans une zone pré-définie sur la lame afin de faciliter ses poissons de localisation suivants; un soin extrême doit être pris en veillant à ce que la cellule est lysée, que le cytoplasme a été dispersée, et que le noyau est visible et intacte, et, comme le diagnostic repose sur les résultats de cette cellule unique, la notation et l'interprétation stricte des lignes directrices devraient être appliquées. Toutefois, dans des mains expérimentées, le poisson est une technique robuste pour diagnostic pré-implantatoire génétique (DPI) en pratique clinique.
Video: FISH pour le diagnostic préimplantatoire génétique
Cell Membranes Learn that membranes are fluid, with components that move, change, and perform vital physiological roles as they allow cells to communicate with each other and their environment. Cell Signaling Learn that living organisms constantly receive and interpret signals from their environment. Cells of multi-cellular organisms also receive signals from other cells, including signals for cell division and differentiation.
The Biology Project: Cell Biology
PCR (short for Polymerase Chain Reaction) is a relatively simple and inexpensive tool that you can use to focus in on a segment of DNA and copy it billions of times over. PCR is used every day to diagnose diseases, identify bacteria and viruses, match criminals to crime scenes, and in many other ways. Step up to the virtual lab bench and see how it works!
PCR Virtual Lab
New Self-Cloning Lizard Found in Vietnam Restaurant
You could call it the surprise du jour: A popular food on Vietnamese menus has turned out to be a lizard previously unknown to science, scientists say. What's more, the newfound Leiolepis ngovantrii is no run-of-the-mill reptile —the all-female species reproduces via cloning, without the need for male lizards. Single-gender lizards aren't that much of an oddity: About one percent of lizards can reproduce by parthenogenesis, meaning the females spontaneously ovulate and clone themselves to produce offspring with the same genetic blueprint. (Related: "Virgin Birth Expected at Christmas—By Komodo Dragon." ) "The Vietnamese have been eating these for time on end," said herpetologist L.
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universcience VOD - La plate-forme vidéo des sciences et des technologies
Water molecules surround the genetic material DNA in a very specific way. Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have discovered that, on the one hand, the texture of this hydration shell depends on the water content and, on the other hand, actually influences the structure of the genetic substance itself. These findings are not only important in understanding the biological function of DNA; they could also be used for the construction of new DNA-based materials. The DNA's double helix never occurs in isolation; instead, its entire surface is always covered by water molecules which attach themselves with the help of hydrogen bonds. But the DNA does not bind all molecules the same way.
How Water Shapes DNA
KEGG for specific organisms KEGG mapping for genome comparsion and combination KEGG as an integrated web resource KEGG for computational analysis KEGG for software development Desktop applications for utilizing KEGG
KEGG Encyclopedia
Animations
Browse our collection of Flash animations that illustrate how the human genome was sequenced, some of the processes and techniques used in sequencing genomes at the Wellcome Trust Sanger Institute and how the DNA code of the human genome is stored and used in our bodies and cells.
Les applets Jmol (modélisation de molécules en 3D) et Jalview (traitement de séquences) sont présentes sous forme d'archive (.jar) à l'intérieur des dossiers. Pour l'utilisateur, il n'y a rien à faire. On charge les pages et les applets se lancent toutes seules ... Néanmoins, votre machine doit disposer de l'environnement java, ce qui n'est pas le cas dans les modèles récents. Le cas échéant, vous devez télécharger J2SE sur le site de SUN puis l'installer sur votre machine. C'est indispensable pour lire les applets java.
Dossier molécules en 3D
(A museum reconstruction of a Neanderthal/credit: iStockPhoto) If your heritage is non-African, you are part Neanderthal, according to a new study in the July issue of Molecular Biology and Evolution . Discovery News has been reporting on human/Neanderthal interbreeding for some time now, so this latest research confirms earlier findings. Damian Labuda of the University of Montreal's Department of Pediatrics and the CHU Sainte-Justine Research Center conducted the study with his colleagues. They determined some of the human X chromosome originates from Neanderthals , but only in people of non-African heritage.
All Non-Africans Part Neanderthal, Genetics Confirm : Discovery News
ScienceDaily (Apr. 21, 2011) — Researchers at Albert Einstein College of Medicine of Yeshiva University have for the first time observed the activity of a single gene in living cells. In an unprecedented study, published in the April 22 online edition of Science , Einstein scientists were able to follow, in real time, the process of gene transcription, which occurs when a gene converts its DNA information into molecules of messenger RNA (mRNA) that go on to make the protein coded by the gene. Robert Singer, Ph.D., co-director of the Gruss Lipper Biophotonics Center at Einstein and professor and co-chair of anatomy and structural biology, is senior author of the paper. The study's lead author is Daniel Larson, Ph.D., previously a member of Dr. Singer's lab and now an investigator at the National Cancer Institute and head of the institute's Systems Biology of Gene Expression Section.
Scientists observe single gene activity in living cells in detail for first time
Agitation de neurones
myExperiment
About The myExperiment Virtual Research Environment enables you and your colleagues to share digital items associated with your research — in particular it enables you to share and execute scientific workflows. You can use myexperiment.org to find publicly shared workflows. If you want further access, and the ability to upload and share workflows, you will need to sign up .Any given gene is associating with a set of annotation terms. If genes share similar set of those terms (annotation profile), they are most likely involved in similar biological mechanisms. The algorithm adopts kappa statistics to quantitatively measure the degree of the agreement how genes share the ~75,000 annotation terms collected by DAVID knowledgebase. For any given gene(s), the tool instantly searches and lists the related genes passed kappa similarity measurement threshold. The searching scope could be within user’s input gene list, selected genome or all genomes (~1.2 million genes) as user’s choice.
DAVID: Gene Functional Classification
SANTE ANIMALE ET PROTECTION ANIMALE
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génétique