background preloader

Super organisms

Facebook Twitter

How do fish make electricity? - Eleanor Nelsen. Cet animal est un expert de la régénération. L’ascidie, ce curieux petit invertébré marin en forme d’outre, a la faculté de renouveler ses tissus très rapidement après de graves lésions. L’étude de ce mécanisme biologique, encore rare, pourrait se révéler précieuse pour la médecine régénérative. Si les ascidiesFermerorganismes marins, filtreurs d’eau de mer. Leur nom est tiré du grec askós qui signifie « outre » en référence à la forme de ces petits animaux. Les ascidies seraient nos plus proches parents invertébrés. étaient un personnage de bande dessinée, elles seraient à coup sûr Wolverine, le X-men au pouvoir auto-guérisseur qui se remet en accéléré de toutes les blessures.

Comme le héros de Marvel, ces petits organismes marins apparus il y a 500 millions d’années environ possèdent – du moins dans leur forme dite « coloniale » – de fascinants pouvoirs de régénération. C’est un modèle fascinant : les ascidies coloniales disposent de plusieurs voies pour construire un même corps. La régénération ou la fabrique du même. Rat-taupe nu. Un article de Wikipédia, l'encyclopédie libre. Des informations de cet article ou section devraient être mieux reliées aux sources mentionnées dans la bibliographie, sources ou liens externes (indiquez la date de pose grâce au paramètre date). Améliorez sa vérifiabilité en les associant par des références à l'aide d'appels de notes. Description[modifier | modifier le code] Le rat-taupe mesure de 8 à 33 cm de long auxquels s'ajoute une queue pouvant aller jusqu'à 8 cm. Son poids varie de 28 g à 1,5 kg[1]. Les rats-taupes nus ont une tête aux muscles de la mâchoire particulièrement développés, avec de grandes incisives proéminentes qu'ils utilisent pour forer leurs galeries.

Une très grande partie de leur cerveau est d'ailleurs dévolue au contrôle et à la sensibilité de la bouche. Rat-taupe nu adulte et ses petits dans leur terrier Mode de vie[modifier | modifier le code] Ils n'ont que peu de prédateurs (certains serpents) et leur plus grand ennemi reste le froid. (en) Paul W. Would You Want a Dog That Was Genetically Engineered to Be Healthier? “Dogs have more genetic diseases than any other species on the planet.” David Ishee told me this early in our conversation. His claim makes sense: there’s no other animal that humans have purposefully bred with an emphasis on form over function—aesthetics over health—for so long. Centuries of inbreeding have left many dog breeds with a severely limited gene pool, and this lack of genetic diversity is to blame for disorders like brachycephaly in bulldogs, hyperuricemia in dalmations, and cardiomyopathy in boxers.

Ishee is a breeder from rural Mississippi who’s on a mission to change all this. Up until now, he’s been using selective breeding to do so. He envisioned an ideal mastiff: 150-170 pounds, 30+ inches at the shoulders, tight-skinned, dry-mouthed, and free of inherited health problems. Ishee has plans to expand his health-focused breeding to other dogs, but he wants a better tool to do so. Enter gene editing. Gene editing for everyone Regulatory crackdown Designer dogs, designer humans? Le blob, une créature mystérieuse - [Parlons peu parlons Science] Ni animal, ni végétal, ni champignon, le blob se veut différent de tous. Créature généralement jaunâtre, vivant souvent dans les sous-bois et déposant du mucus sur son passage, le blob présente une liste de caractéristiques fascinantes. Photo credit : weezerthewonderful via / CC BY-NC-SA Une cellule de plusieurs m² qui bouge ! Le blob se définit comme un organisme vivant primitif puisqu’il existe depuis au moins 500 millions d’années.

Unicellulaire, le blob est un protiste que l’on appelle myxomycète. Pouvant atteindre un tour de taille de 3 à 4 mètres, le blob est chaque jour deux fois plus grand que la veille. Résistant, le blob s’adapte à son environnement. Photo credit : palustrina via / CC BY-NC-SA Sans cervelle, le blob apprend et enseigne Outre sa carte d’identité et ses fonctions primaires, le blob ne cesse d’impressionner la communauté scientifique qui l’observe attentivement.

Durant cette étude, les chercheurs ont appris au blob que le sel est inoffensif. Grow plants without water. Alice Moynihan Ever since humanity began to farm our own food, we’ve faced an unpredictable frenemy: rain. It comes and goes without much warning, and a field of lush leafy greens one year can crackle, dry up and blow away the next. Food security and fortunes depend on rain, and nowhere more so than in Africa, where 96% of farmland depends on rain instead of the irrigation common in more-developed places. It has consequences: South Africa’s ongoing drought — the worst in three decades — will cost it at least a quarter of its corn crop this year. Biologist Jill Farrant (TED Talk: How we can make crops survive without water) of the University of Cape Town in South Africa says that nature has plenty of answers for people who want to grow crops in places with unpredictable rainfall. She is hard at work finding a way to take traits from rare wild plants that adapt to extreme desiccation and use them in food crops.

Extreme conditions produce extremely tough plants. 5 Strange Genetic Mutations, From Unbreakable Bones To Fish Odor Syndrome. Strange genetic mutations often play into the storylines of Hollywood action films, but in reality you don’t have to be a superhero to be a “mutant.” In fact, genetic mutations exist in the DNA of every person on Earth, and helped to shape humans into what we are today. Some mutations, however, are more striking and strange than others. Here is a list of some of the most fascinating genetic mutations found in man.

Ectrodactyly People with ectrodactyly, also known as a split-hand/split-foot malformation or “lobster claw hand,” have a cleft where the middle finger or toe should be. Ectrodactyly causes malformation of the hands or feet. Unbreakable Bones Low-density lipoprotein receptor-related protein 5, (LRP5) is one of the genes that controls your bone density. HIV Resistance Although highly treatable today, HIV infections still seriously compromise the immune system, putting patients at risk of developing AIDS and dying from disease complications. High Altitude Sickness Resistance. Brazilian Wasp Venom Kills Cancer Cells, But Not Healthy Cells. Wasps get their fair share of bad press. They have painful stingers, and they're not as useful (or cute) to us as bees. However, their time to step in the spotlight may be just around the corner: Their venom has been shown to attack cancer cells while leaving healthy cells alone.

The cancer-targeting toxin in the wasp is called MP1 (Polybia-MP1) and until now, how it selectively eliminates cancer cells was unknown. According to new research, it exploits the atypical arrangement of fats, or lipids, in cancer cell membranes. Their abnormal distribution creates weak points where the toxin can interact with the lipids, which ultimately pokes gaping holes in the membrane. These are sufficiently large for essential molecules to start leaking out, like proteins, which the cell cannot function without.

The wasp, Polybia paulista, which produces the venom containing MP1. Researchers Identify Genetic Recipe For Lizard Tail Regeneration. Animals Fight Bacteria Using Stolen Defense Systems. Humans aren’t the only ones on the planet to be engaging in a battle against bacteria; these organisms are also constantly fighting each other over scarce resources. They’re some of the oldest inhabitants of Earth, so they’ve had a while to evolve the sophisticated antibacterial weaponry used to kill the competition. Some bacteria, for example, inject deadly enzymes into rival cells that rapidly degrade their protective walls, causing the contents of the cell to spill out. While it can take millions of years for such sophisticated defense mechanisms to evolve, it doesn’t take them long to spread in bacterial communities.

That’s because they can play pass-the-parcel with their genes in a process called horizontal gene transfer. Now, new research has suggested that some animals have joined in on this gene swapping party, and have acquired their own set of antibacterial weaponry from certain microbes. [Via University of Washington Health Sciences/UW Madison and Nature] Sea Slug Steals Photosynthesis Genes From Algae. The brilliant emerald green sea slug, Elysia chlorotica, spends months living on sunlight just like plants. It’s been called the photosynthesizing sea slug in the past, but how it manages to do this as well as it does is a complete mystery. In a new study appearing in the Biological Bulletin, researchers reveal that the sea slug has incorporated genes from the algae that it eats. "There is no way on earth that genes from an alga should work inside an animal cell," says Sidney Pierce from the University of South Florida.

"And yet here, they do. They allow the animal to rely on sunshine for its nutrition. So if something happens to their food source, they have a way of not starving to death until they find more algae to eat. " Chloroplast are plant organelles that contain chlorophyll, the green photosynthetic pigment. But until now, no one knew for sure how the slugs manage to maintain these pilfered chloroplasts. Read this next: Dear Parents, Let’s Talk About Measles. Squid Can Recode Their Own Genetics.

A species of squid has been observed editing its own RNA to an amazing extent, creating the capacity to respond to changes in its environment by altering its proteins and therefore its entire body. The discovery could explain why squid seem to be one of the few species doing well out of the damage humans are inflicting on the oceans and climate. Messenger RNA (mRNA) transfers genetic information from our DNA to the ribosomes that synthesize proteins within cells. Most of the time, the mRNA is transcribed reliably, serving as an instructional memo for protein building.

As a paper published in eLife puts it: “The central dogma of biology maintains that genetic information passes faithfully from DNA to RNA to proteins.” Occasionally, however, the memo gets changed in transmission. The paper describes this as “organisms using RNA as a canvas to modify and enrich the flow of information.” "It was astonishing to find that 60% of the squid RNA transcripts were edited,” says Eisenberg.