Posts tagged biology

Posts tagged biology
Transgendered bellbird found in New Zealand
Biologists at the Zealandia eco-sanctuary in New Zealand have spotted a bellbird that exhibits features and behaviour of both male and female members of the species.
The bird hatched in early 2011, and DNA testing then showed it as female, but since then its development has been rather different to normal female korimakos.
Normally, female bellbirds have a white feather pattern but the chick bean to show signs of the dark plumage normally seen on male birds. It also began to behave in a masculine way, not flitting between flowers like a female bellbird but instead moving with purpose, ready to defend its territory.
The bird’s calls are unusual too. It makes both male calls and the distinctive “chup chup” normally heard from females, but the latter are louder and more frequent that is normal.
Zealandia conservation officer Erin Jeneway told the Dominion Post: “There’s something we can’t pin down. We haven’t seen anything like this before”. Victoria University biologist Ben Bell added: “It could be due to a hormonal imbalance or it could be a reaction to shock or an incomplete moult — given the appearance and behaviour, any of those would be unusual though.”
Scientists discover novel diabetes and obesity therapy, and potential cause of major side effects from hedgehog inhibitors used as a cancer treatment
Cancer, diabetes, and excess body weight have one thing in common: they alter cellular metabolism. Scientists from the Max Planck Institute of Immunobiology and Epigenetics in Freiburg and the Medical University of Vienna together with an international research team have jointly resolved a new molecular circuit controlling cellular metabolism. The previously unknown signalling pathway, acting downstream of the hedgehog protein enables muscle cells and brown fat cells to absorb sugars without relying on insulin. Substances that selectively activate the signalling pathway could thus be utilized in the treatment of diabetes and obesity. With their results, the researchers are also able to explain why various new anti-cancer agents have induced mysterious pronounced side effects in the clinics.
Scientists have proved a 60-year-old theory about how nerve signals are sent around the body at varying speeds as electrical impulses.
Researchers tested how these signals are transmitted through nerve fibres, which enables us to move and recognise sensations such as touch and smell.
The findings from the University of Edinburgh have validated an idea first proposed by Nobel laureate Sir Andrew Huxley.
It has been known for many years that an insulating layer – known as myelin – which surrounds nerve fibres is crucial in determining how quickly these signals are sent.
This insulating myelin is interrupted at regular intervals along the nerve by gaps called nodes.
Scientists, whose work was funded by the Wellcome Trust, have now proved that the longer the distance between nodes, the quicker the nerve fibres send signals down the nerves.
The theory that the distance between these gaps might affect the speed of electrical signals was first proposed by Sir Andrew Huxley, who won the Nobel Prize in 1963 for his work on electrical signalling in the nervous system, and who died earlier this year.
The study, published in the journal Current Biology, will help provide insight into what happens in people with nerve damage. It will also shed light on how nerves develop before and after birth.
Professor Peter Brophy, Director of the University of Edinburgh’s Centre for Neuroregeneration, said: “The study gives us greater insight into how the central and peripheral nervous systems work and what happens after nerves become injured. We know that peripheral nerves have the capacity to repair, but shorter lengths of insulation around the nerve fibres after repair affect the speed with which impulses are sent around the body.”
The researchers found that when the myelin reached a certain length, the speed with which nerves impulses were conducted reached a peak.
The study, carried out in mice, also confirmed that a protein – periaxin – plays a key role in regulating the length of myelin layers around nerve fibres.
(Source: eurekalert.org)
Researchers at the University of Illinois at Urbana-Champaign and Tufts University say they have invented functional electronic implants that can dissolve after programmable time periods. To demonstrate the system, which could aid in healing during the first few crucial days after an operation, they implanted one in a rat. It created a temporary temperature increase to sterilize a wound, and then it dissolved after 15 days. The researchers reported the development this week in the journal Science.
Biomedical researchers are turning to the idea of “programmable degradation” because it is difficult to develop materials that remain compatible with human tissue over the long term. Medical implants or drug-delivery systems that do their work and then disappear are ideal. To develop the electronic implants, the researchers encased them in silk. That material’s characteristics, particularly its crystallinity, can be adjusted so that its degradation time can be anywhere from seconds to years.
The electronics inside the silk were based on nanometers-thick sheets or ribbons of silicon, called silicon nanomembranes. The materials have been previously used to make experimental transistors, diodes, complementary logic devices, and photocells for flexible surfaces. Whereas a conventional silicon wafer or a chip would take about a thousand years to dissolve in biofluids, says John A. Rogers, who led the research at the University of Illinois, a nanomembrane is gone in a couple of weeks.
Bioengineers Introduce ‘Bi-Fi’ — The Biological ‘Internet’
If you were a bacterium, the virus M13 might seem innocuous enough. It insinuates more than it invades, setting up shop like a freeloading houseguest, not a killer. Once inside it makes itself at home, eating your food, texting indiscriminately. Recently, however, bioengineers at Stanford University have given M13 a bit of a makeover.
The researchers, Monica Ortiz, a doctoral candidate in bioengineering, and Drew Endy, PhD, an assistant professor of bioengineering, have parasitized the parasite and harnessed M13’s key attributes — its non-lethality and its ability to package and broadcast arbitrary DNA strands — to create what might be termed the biological Internet, or “Bi-Fi.” Their findings were published online Sept. 7 in the Journal of Biological Engineering
Using the virus, Ortiz and Endy have created a biological mechanism to send genetic messages from cell to cell. The system greatly increases the complexity and amount of data that can be communicated between cells and could lead to greater control of biological functions within cell communities. The advance could prove a boon to bioengineers looking to create complex, multicellular communities that work in concert to accomplish important biological functions.
Kansas State University researchers have discovered a molecule that may be capable of delivering drugs inside the body to treat diseases.
For the first time, researchers have designed and created a membrane-bounded vesicle formed entirely of peptides — molecules made up of amino acids, the building blocks of protein. The membrane could serve as a new drug delivery system to safely treat cancer and neurodegenerative diseases.
A study led by John Tomich, professor of biochemistry at Kansas State University, has been published in the journal PLOS ONE in September, and a patent for the discovery is pending.
(Source: k-state.edu)
At any given moment, millions of cells are on the move in the human body, typically on their way to aid in immune response, make repairs, or provide some other benefit to the structures around them. When the migration process goes wrong, however, the results can include tumor formation and metastatic cancer. Little has been known about how cell migration actually works, but now, with the help of some tiny worms, researchers at the California Institute of Technology (Caltech) have gained new insight into this highly complex task.
The team’s findings are outlined this week online in the early edition of the Proceedings of the National Academy of Sciences (PNAS).
A new study, published online in Biology Letters on September 19, has utilized a massive molecular dataset to reconstruct the evolutionary history of lizards and snakes. The results reveal a surprising finding about the evolution of snakes: that most snakes we see living on the surface today arose from ancestors that lived underground.
(Source: newswise.com)
The first detailed and complete picture of a protein complex that is tied to human birth defects as well as the progression of many forms of cancer has been obtained by an international team of researchers led by scientists with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab). Knowing the architecture of this protein, PRC2, for Polycomb Repressive Complex 2, should be a boon to its future use in the development of new and improved therapeutic drugs.
Researchers from ETH Zurich have quite literally created a “cell phone”: they have reprogrammed mammalian cells in such a way that they can “phone” each other via chemical signals.
Telephoning is a mutual exchange of information: A phones B and they both agree what B should do. Once this is done, Party B phones Party A to let him or her know. A no longer phones B. During this two-way communication, electrical signals are sent, and for their transmission suitable devices are necessary.
Based on this formula, a team of bioengineers headed by Martin Fussenegger and Jörg Stelling at ETH Zurich’s Department of Biosystems Science and Engineering in Basel has programmed mammalian cells in such a way that two cells can communicate via chemical signals. The scientists have thus incorporated a synthetic two-way communication system into mammalian cells for the first time that also responds to concentration differences in the signal molecules. The researchers used suitable signal molecules and constructed “devices” out of biological components that receive, process and respond accordingly to the signals. The devices consist of suitable genes and their products, proteins, which are linked to each other logically.