Life & Non-humans

Tailor-made proteins manufactured in novel E. coli system

The prospect of using bacteria to manufacture complex human proteins for use in therapeutic drugs is a step closer thanks to new research published today in Science. Researchers from Switzerland and the UK report they have engineered the bacterium Escherichia coli to carry a vital piece of cell machinery that adds sugar molecules to newly synthesized proteins by a process known as glycosylation. The finding opens up the possibility of producing complex human proteins such as Factor VIII and the hormone erythropoietin, which stimulates the production of red blood cells by stem cells in bone marrow. Both these proteins, which require the addition of sugar molecules to function properly, are currently produced by culturing mammalian cells, which can be a costly and technically difficult process.

Insects’ survival, mating decrease with age in wild

A unique insect has given researchers the opportunity to study aging in the wild for the first time. “Aging – or senescence – has been seen under controlled conditions in the lab, but never before in insects living in their naturally evolved habitat,” says U of T zoology doctoral candidate Russell Bonduriansky. “Our study of antler flies shows these animals do age in the wild.” Bonduriansky and co-researcher Chad Brassil, both of the evolutionary ecology group at U of T, studied male antler flies to see if there was aging – a term used to denote a deterioration of the body’s vital functions, not chronological time. The two zoologists examined the flies to see if their abilities to survive to the next day and to mate deteriorated with age.

Researchers Discover Unusual Protein Structure: A Knot

Researchers have determined the structure of a protein with a surprising feature in it: a knot. This is the first time a knot has been found in a protein from the most ancient type of single-celled organism, an archaebacterium, and one of only a few times a knot has been seen in any protein structure. This very unusual protein shape finding is a result from the NIGMS Protein Structure Initiative, a 10-year effort to determine 10,000 unique protein structures using fast, highly automated methods.

Generalized anxiety disorder, peptic ulcers linked

A new finding of a link between an anxiety disorder and peptic ulcer disease lends support to the view that this gastrointestinal disease and anxiety disorder may share a common link. In recent years, attention has focused on a more biological element with the identification of bacteria as a cause of peptic ulcers. “The identification of Helicobacter pylori as an infectious cause of peptic ulcer disease has been considered by many to disprove the possibility that there is an important relationship between anxiety disorders and gastrointestinal disease,” says study author Renee D. Goodwin, Ph.D., from the Department of Epidemiology at the Mailman School of Public Health at Columbia University in New York City. “Over the last several years research on the causes and treatments for peptic ulcer disease has neglected the links with psychiatric/psychological factors,” she notes.

‘Outlaw’ organism turns informant

In a critical scene in the film remake of the classic 1960s TV series “The Fugitive,” actor Harrison Ford sheds his coat and replaces it with another. This simple deception allows him to escape detection by the swarm of police officers trailing him. The African trypanosome, a blood parasite that causes African sleeping sickness, is, like Ford’s character in the film, a fugitive that changes its “coat” each time the human immune system is about to nab it. Woven of 10 million copies of a single sugar-coated molecule called a glycoprotein, the trypanosome’s surface changes every few days by virtue of a switch that activates a new gene.

Researchers ID new mammal down under

In the current crisis of global biodiversity loss, the discovery of new species is a welcome addition. But the recent finding that the mountain brushtail possum, an arboreal marsupial mammal of Australian wet forests, is actually made up of two species also poses new conservation challenges. The new species is proposed in an article in the latest Australian Journal of Zoology (Volume 50, Issue 4), authored by Earthwatch-supported biologist Dr. David Lindenmayer (Australian National University) and colleagues. “Geographic dimorphism in the Mountain Brushtail Possum (Trichosurus caninus) – the case for a new species,” describes how the northern and southern populations of the mountain brushtail possum are both morphologically and genetically distinct.

Cell Transfer Restores Sperm Production in Infertile Mice

Scientists have successfully restored sperm production in once-infertile mice by transplanting specialized cells that are critical to sperm development. The research, reported on the Web site of the journal Biology of Reproduction, may give scientists a better understanding of how Sertoli cells ? which surround spermatogenic stem cells ? nourish sperm production and the survival of stem cells.

Using Computers, Scientists Successfully Predict Evolution of E. Coli

For more than a decade, researchers have been trying to create accurate computer models of Escherichia coli (E. coli), a bacterium that makes headlines for its varied roles in food poisoning, drug manufacture and biological research. By combining laboratory data with recently completed genetic databases, researchers can craft digital colonies of organisms that mimic, and even predict, some behaviors of living cells to an accuracy of about 75 percent. Now, NSF-supported researchers at the University of California at San Diego have created a computer model that accurately predicts how E. coli metabolic systems adapt and evolve when the bacteria are placed under environmental constraints.

Defeating ‘clingy’ bacteria could help treat urinary tract infections

Clingy bacteria often spell trouble. Scientists have discovered how bacteria manufacture hair-like fibers used to cling to the lining of the kidney and bladder where they cause urinary tract infections (UTIs). The results are published in the Nov. 15 issue of the journal Cell. “Our findings should lead to new drugs to treat UTIs by blocking the formation of these protein fibers,” says study leader Scott J. Hultgren, Ph.D., the Helen Lehbrink Stoever Professor of Molecular Microbiology. “They also should improve our general understanding of how disease-causing bacteria build, fold and secrete proteins that enable them to cause disease.”

Climate Change Linked to Population Shifts Among Mammals

Scientists have shown, for the first time, that changes in a large-scale climate system can synchronize population fluctuations in multiple mammal species across a continent-scale region. The study, to be published in the 14 November 2002 issue of the journal Nature, compares long-term data on the climate system known as the North Atlantic Oscillation with long-term data from Greenland on the population dynamics of caribou and muskoxen, which are large mammals adapted to breeding in the Arctic.

Choreography, not molecular prepattern, creates vertebrate building blocks

In a study that combines state-of-the-art biological imaging with gene expression analysis, scientists at the California Institute of Technology have uncovered a fundamental insight into the way embryonic cells and tissue move about to form key structures along the vertebrate axis. The study, which could lead to a better understanding of human development, takes advantage of the accessibility of chick embryos to embryonic manipulation. The study enters on segments known as somites, which form along either side of the future spinal cord of an embryo. Somites give rise to mature structures such as ribs, individual vertebrae, and even skin. The key role of somite segmentation in the patterning of the nervous system and the vertebral column has been long known. But the question of precisely how an individual somite buds off from a block of tissue in a pattern that is repeated all along the animal’s torso, from head to tail, is poorly understood.

Drug Averts Parkinson’s in Fruit Flies, New Approaches Possible in Humans

Scientists have averted the onset of neurodegenerative disease in fruit flies by administering medication to flies genetically predisposed to a disorder akin to Parkinson’s disease. The result suggests a new approach to the treatment of human disorders including Parkinson’s and Alzheimer’s diseases. Parkinson’s disease is the second most common human neurodegenerative disorder, characterized by tremors, postural rigidity and progressive deterioration of dopaminergic neurons in specific areas of the brain. Despite the evolutionary gulf separating humans and fruit flies, neurotoxicity unfolds in a similar manner in both species.

Emperor Penguin Colony Struggling With Iceberg Blockade

The movements of two gigantic Antarctic icebergs appear to have dramatically reduced the number of Emperor penguins living and breeding in a colony at Cape Crozier, according to two researchers who visited the site last month. The colony is one of the first ever visited by human beings early in the 20th century. “It’s certain that the number of breeding birds is way down” from previous years, said Gerald Kooyman, a National Science Foundation-funded researcher at the Scripps Institution of Oceanography in La Jolla, Calif.

Cholestrol Drug Could Lead to New Therapy for Multiple Sclerosis

While cautioning that their findings still must be evaluated in humans, University of California, San Francisco and Stanford University Medical Center researchers report that the cholesterol-lowering drug atorvastatin (Lipitor) significantly improved, prevented relapses or reversed paralysis in mice with an experimental disease that closely resembles multiple sclerosis. The study, reported in the November 7 issue of Nature, was conducted in mice with experimental autoimmune encephalomyelitis (EAE), the standard animal model for multiple sclerosis.