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Tag: "primitive" at biology news

A resetting signal keeps circadian rhythm on track in Drosophila fruit flies

...ls is much more complicated and the tools much too primitive to allow a similar network approach at this time. Flies are state-of-the art. Fortunately, their circadian clocks and even neural mechanisms are quite conserved with mammals." "We were curious about how these brain cells stay synchronized, so we c...

Missing fossil link 'Dallasaurus' found

...l the discovery of Dallasaurus, however, only five primitive forms with land-capable limbs were known, all of t...o three major lineages. Although a small number of primitive mosasaur have been known to retain land-capable limbs, they were thought to be an ancestral group se...

New view of cancer: 'Epigenetic' changes come before mutations

...se of insulin-like growth factor 2 (IGF2) had more primitive precursor cells in the lining of the colon than normal mice. When these mice also carried a colon-cancer-causing genetic mutation, they developed twice as many tumors as mice with normal IGF2 levels. The extra IGF2 stemmed not from a genetic problem,...

Newly discovered birdlike dinosaur is oldest raptor ever found in South America

...avis, an animal previously considered to be a very primitive bird, actually constitute a separate branch of the dromaeosaurid family tree. This branch is distinct from Velociraptor and other Laurasian dromaeosaurids, including some of the famous feathered dinosaurs from China. Because Rahonavis has long and ...

Why Christmas trees are not extinct

... which arose more than 280 million years ago, have primitive conduits that are short and inefficient and evolve...e 400 million years ago in ferns, cycads and other primitive plants. But flowering plants evolved longer conduits to get around the problem. "The evolution of ...

U-M scientists discover identifying markers for primitive blood-forming stem cells

... not possible with existing markers. Knowing where primitive hematopoietic stem cells hang out in blood-forming organs will give scientists important clues to how they work, according to Morrison. For this reason, the identification of markers that allow the localization of HSCs in tissues has been a long-soug...

North & South American researchers find architectural abnormalities in T. cruzi ribosome

... health implications, Frank sees the parasite as a primitive link to modern eukaryotes and its ribosome as a source of potential insights into the evolution of more complex organisms. "Ribosomes perform the translation of genetic information into protein in all organisms," Frank said. "The principle is always...

Field tested: Grasslands won't help buffer climate change as carbon dioxide levels rise

...atoms." A key distinction separating the cells of primitive organisms like bacteria, known as prokaryotes, fro...own as microcompartments, which appear to serve as primitive organelles inside bacterial cells, carrying out special reactions in their interior. "Students who ...

Nighttime Dying Linked To Sleep Apnea From Brain Cell Loss

...atoms." A key distinction separating the cells of primitive organisms like bacteria, known as prokaryotes, fro...own as microcompartments, which appear to serve as primitive organelles inside bacterial cells, carrying out special reactions in their interior. "Students who ...

New discovery blurs distinction between human cells and those of bacteria

...atoms." A key distinction separating the cells of primitive organisms like bacteria, known as prokaryotes, fro...own as microcompartments, which appear to serve as primitive organelles inside bacterial cells, carrying out special reactions in their interior. "Students who ...

Molecular mechanism of feather formation found

...kens, and are not characterized as downy. The more primitive young chicken feathers, which are downy, are called plumalaceous. "We don't have empirical evidence for this yet, but mathematical analyses lead us to believe that the addition of a third signaling factor leads to the development of the more complex...

Insight into our sight: A new view on the evolution of the eye lens

...omponents of vertebrate eyes and those of the more primitive light-sensing systems of invertebrates. The findin... single crystallin gene, which is expressed in its primitive light-sensing system. The identification of the sea squirt's crystallin strongly suggests that it is...

Simple sea sponge helps scientists understand tissue rejection

...tion. Researchers believe that gray cells may be a primitive form of our immune system's human killer cells. Fernndez-Busquets has also been researching the role of the molecule called aggregation factor proteoglycan, which he has recently identified as another potential player in sponge tissue rejection reac...

For first time, brain cells generated in a dish

...nitor the entire sequence of cell development from primitive states to functional neurons and expose the electr...in in a region called the subventricular zone. The primitive cells mature along the way, finishing as neurons in a spot called the olfactory bulb. In the labora...

Bees, Brains and Addiction

...can tell scientists much about the workings of the primitive portion of our brains that lead some of us to become addicted to tobacco, alcohol or other drugs. This region of the brain exerts such a powerful influence on the behavior of humans and other animals that a rat will work so tirelessly when it is rew...

Map of life on Earth could be used on Mars

... techniques to render a more coherent story of how primitive life arose and diverged on Earth ?with implication... genetic relationships between what we think of as primitive organisms through trait development. The relationships between early forms of life can illuminate th...

Researchers Closer To Helping Hearing-Impaired Using Stem Cells

...cals known to encourage stems cells to change into primitive neurons. The bone marrow cells took the shape and other characteristics of neurons. Next, they exposed the cells to two molecules that are secreted from nearby tissues of the ear during embryonic development. The two molecules -- known as Sonic hedge...

At the molecular level, the predator is the prey

... compound found in some puffer fish, octopuses and primitive chordates. It is used in low concentrations to treat morphine and heroine addicts. It's also the "zombie" drug used by Haitian voodoo ritualists. Despite its action at the molecular level, the evolution of TTX in some organisms is viewed by ecologis...

NHGRI targets 12 more organisms for genome sequencing

...as chosen because it belongs to the first group of primitive vertebrates that developed jaws, an important step in vertebrate evolution. Other innovations in this group of animals include an adaptive immune system similar to that of humans, a closed and pressurized circulatory system, and myelination of the ne...

Ancient immune defense mechanism is no match for HIV-1

... that mammalian cells infected with HIV-1 engage a primitive defense mechanism that was previously observed only in plants and invertebrates. The research also reveals exactly how HIV-1 successfully thwarts this rare form of immunity in vertebrate cells. However, elucidation of the mechanism HIV-1 uses to prot...

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