Molecular Biology
edyong | July 8, 2009It's 1964, and a group of Canadian scientists had sailed across the Pacific to Easter Island in order to study the health of the isolated local population. Working below the gaze of the island's famous statues, they collected a variety of soil samples and other biological material, unaware that one of these would yield an unexpected treasure. It contained a bacterium that secreted a new antibiotic, one that proved to be a potent anti-fungal chemical. The compound was named rapamycin after the traditional name of its island source - Rapa Nui.
Skip forward 35 years and rapamycin has made a…
pharyngula | July 1, 2009The difference between biology and chemistry: biologists ask how natural systems and molecules work, while chemistry wants to know how to artificially re-synthesize natural biomolecules. Tsien favors a synthetic approach, asking hwo to build new molecules that will perform amusing and useful functions in biology. He compares it to architecture on a molecular scale that is also a rigorous test of one's understanding of molecular function.
He thinks biology has the most interesting grand questions in all of science (hooray!). He also likes pretty colors. However, he thinks that…
pharyngula | July 1, 2009Chalfie is interested in sensory mechanotransduction—how are mechanical deformations of cells converted into chemical and electrical signals. Examples are touch, hearing, balance, and proprioception, and (hooray!) he references development: sidedness in mammals is defined by mechanical forces in early development. He studies this problem in C. elegans, in which 6 of 302 nerve cells detect touch. It's easy to screen for mutants in touch pathways just by tickling animals and seeing if they move away. They've identified various genes, in particular a protein that's involved in transducing touch…
pharyngula | July 1, 2009This is a wonderful video: it's Richard Dawkins interviewing Craig Venter and getting a tour of his amazing sequencing facility. It also reveals how much the technology is changing.
pharyngula | July 1, 2009This morning was a long session broken into two big chunks, and I'm afraid it was too much for me — my recent weird sleep patterns are catching up with me, which didn't help at all in staying alert.
Robert Huber: Intracellular protein degradation and its control
This talk was a disaster. Not because it wasn't good, because it was; lots of fine, detailed science on the regulation of proteases by various mechanisms, with a discussion of the structure and function of proteasomes, accompanied by beautiful mandalas of protein structure. No, the problem was that this listener's jet lag has been…
pharyngula | June 1, 2009I admit, I was initially put off by the mere title of Nick Lane's new book, Life Ascending: The Ten Great Inventions of Evolution(amzn/b&n/abe/pwll). I'm one of those many biologists who is adamant about the absence of direction in evolutionary history, and ascending just sounds too much like life climbing the rungs of the ladder of life, so I picked it up in a somewhat prejudicial mood.
Have no fear, though, I was won over. Right at the beginning, he admits that it is a subjective list; his criteria for including the ten chosen evolutionary innovations are that it had to revolutionize…
pharyngula | May 1, 2009Ray Comfort has made a post on the swine flu. You know already what kind of idiotic tripe he's going to trot out.
The spread of the so-called 'swine flu' demonstrates yet again how useless and sometimes deadly a mutation can be. Furthermore, as the infection spreads around the world, the search for an antidote is desperately sought, but the very fact that the virus is seen as something to be opposed actually supports the Biblical view of this world. It is always good and right to oppose sickness, but in evolutionary terms, why don't humans simply resign themselves to it and allow the strong…
edyong | April 30, 2009These cells look like fairly typical bone cells. They appear to be connected to each other by thin branch-like projections and are embedded in a white matrix of fibres. At their centres are dark red spots that are probably their nuclei. But it's not their appearance that singles out these extraordinary cells - it's their source. You're looking at the bone cells of a dinosaur.
They come from an animal called Brachylophosaurus, a duck-billed dinosaur that lived over 80 million years ago. By looking at one of its thigh bones, Mary Schweitzer from North Carolina State University has managed to…
grrlscientist | April 29, 2009tags: Antigen Shift, Influenza Viruses, molecular biology, virology, microbiology, streaming video
This video discusses the process of antigen shift in influenza viruses, such as the H1N1 "swine flu" that has recently been identified in Mexico and in quite a few other countries, including in NYC [1:18]
edyong | April 26, 2009It is literally very difficult to mend a broken heart. Despite its importance, the heart is notoriously bad at regenerating itself after injury. If it is damaged - say, by a heart attack - it replaces the lost muscle with scar tissue rather than fresh cells. That weakens it and increases the chance of heart failure later on in life. No wonder that heart disease is the western world's leading cause of death and illness.
If that picture seems bleak, two teams of scientists have some heartening news for you. The first has found that the heart does actually have the ability to renew its cells,…
grrlscientist | April 15, 2009tags: performance horses, polo, racing, tendon injury, stem cell research
Horses clear a jump during the Challenge Cup Handicap Steeplechase
on the second day of the Cheltenham Festival in the UK.
Image: BBC News.
Those of you who follow my writings about racehorses and other high-performance horses will be interested to learn that several companies that I've been following have been redirecting their stem-cell research that they originally developed to help injured horses to help people recover from Achilles tendon injuries.
After a tendon or ligament tear, both horses and people…
pharyngula | April 13, 2009
My first column in the Guardian science blog will be coming out soon, and it's about a recent discovery that I found very exciting…but that some people may find strange and uninteresting. It's all about the identification of nodal in snails.
Why should we care? Well, nodal is a rather important — it's a gene involved in the specification of left/right asymmetry in us chordates. You're internally asymmetric in some important ways, with, for instance, a heart that is larger on the left than on the right. This is essential for robust physiological function — you'd be dead if you were…
grrlscientist | April 8, 2009tags: microbiology, astrobiology, new species, Indian Space Research Organization, bacteria
Bacterial colonies.
Image: Hub Testing Laboratory [larger view].
According to a recently published press release, three new species of bacteria have been discovered in the upper stratosphere by Indian scientists in an experiment conducted by the Indian Space Research Organization (ISRO). This discovery lends some credence to the hypothesis that life might have originated elsewhere in the cosmos and was seeded on Earth after colliding with a foreign body, perhaps a comet or asteroid, that was…
grrlscientist | April 8, 2009tags: lories, Loriinae, Loriidae, ornithology, molecular biology, natural history museums
A young pair of Meyer's Lories (Lorikeets), Trichoglossus flavoviridis meyeri.
Image: Iggino [larger view].
"Can you help us identify a mystery lory in our collection?"
I was pleasantly surprised to find this email request from Donna Dittmann, Collections Manager and Museum Preparator for the Section of Genetic Resources at Louisiana State University Museum of Natural Science in Baton Rouge, Louisiana.
"Sure," I wrote back. "Send it to me and I'll see what I can do."
I, and some of my lories,…
pharyngula | April 2, 2009
The history of venoms is a wonderful example of an evolutionary process. We're all familiar with the idea of venomous snakes, but the cool thing is that when we examine exactly what it is they're injecting into their prey, it's a collection of proteins that show a nested hierarchy of descent. Ancient reptiles had a small and nasty set of poisons they would use, and to improve their efficacy, more and more have been added to the cocktail; so some lizards produce venomous proteins, while the really dangerous members of the Serpentes produce those same proteins, plus a large array of others.…
neurophilosophy | April 1, 2009It is now well established that the adult mammalian brain contains stem cells which continue to generate new neurons throughout life. This discovery, and subsequent research, has transformed the way we think about the brain. It is, for example, known that physical and mental exercise can stimulate the growth of new nerve cells in a part of the brain which shrinks in Alzheimer's and depression, and so it is believed that such activities can reduce the risk of both conditions.
Despite all this, little is known about the mechanisms by which neural stem cells are directed to generate neurons.…
grrlscientist | March 25, 2009tags: evolutionary biology, speciation, species flocks, molecular phylogeny, behavioral ecology, Synodontis species, squeaker catfish, cuckoo catfish, Lake Tanganyika, peer-reviewed paper
The Cuckoo Catfish, Synodontis multipunctatus [Siluriformes: Mochokidae].
This is the only fish that is a known brood parasite.
This is one of the species included in this newly-published study.
Image: orphaned.
One of the groups of fishes that I worked with as an aquarist for nearly my entire life are the synodontids, often known as "squeaker catfish" for their ability to make high-pitched sounds.…
grrlscientist | March 21, 2009Would you like to play a new computer game and help scientists analyze protein chemistry -- at the same time? Here is a fun and interesting computer puzzle game that is designed to fold proteins -- the objective is to correctly fold a protein into the smallest possible space. This game, Foldit, which University of Washington biochemist David Baker helped create, is being played by thousands of people around the world. Baker is using Foldit to help him analyze the structure of proteins, because humans are a lot smarter at this than supercomputers. The results from this game are helping Baker…
pharyngula | February 13, 2009In a potentially exciting development, researchers have announced the completion of a rough draft of the Neandertal genome in a talk at the AAAS, and in a press conference, and the latest issue of Science has a number of news articles on the subject. And that is a reason for having some reservations. There is no paper yet, and science by press release raises my hackles, and has done so ever since the cold fusion debacle. Not that I think this is a hoax or error by any means, but it's not a good way to present a scientific observation.
Also, the work has some major limitations right now. They'…
grrlscientist | December 24, 2008tags: parrots, Psittaciformes, evolution, molecular phylogeny, ornithology, Neornithes
Red-crowned Amazon parrot, Amazona viridigenalis, at Elizabeth Street Parrotry, Brownsville, Texas.
Image: Joseph Kennedy, 7 April 2008 [larger view].
Nikon D200, Kowa 883 telescope TSN-PZ camera eyepiece 1/750s f/8.0 at 1000.0mm iso400.
One of the most contentious issues among scientists who study the evolution of birds is identifying precisely when the modern birds (Neornithes) first appeared. This is due to conflicts between the fossil record and molecular dating methodologies. For example,…