(Press-News.org) The world's tiniest nuclear genome appears to have "snipped off the ends" of its chromosomes and evolved into a lean, mean, genome machine that infects human cells, according to research published today by University of British Columbia scientists.
Until recently, E. cuniculi, a parasitic fungus commonly found in rabbits that can also be fatal to immunocompromised humans, has been widely regarded as having the smallest known nuclear genome. At 2.9 millions base pairs (Mbp) and approximately 2,000 genes, the genome of E. cuniculi is less than one-two thousandth the size of the human genome.
But now, a team of researchers led by UBC Botany Prof. Patrick Keeling sequenced the genome of a closely related parasite that makes the E. cuniculi genome seem positively king-sized. The genome of E. intestinalis, a sister species of E. cuniculi that infects human intestines, is 20 per cent smaller, at only 2.3Mbp.
"On one end of the spectrum, genomes can get larger almost without limit, but there is a limit to how small they can get – they can't be less than zero," says Keeling, whose work is published in today's issue of the journal Nature Communications. "And the question that fascinated us was 'in an already tiny genome, what else can be lost'?"
Keeling and a team of researchers from Switzerland, Canada and the U.S. compared the genome of E. cuniculi and E. intestinalis and found little difference between the chromosome "cores" but that the ends were all "trimmed" in E. intestinalis.
"The chromosomes are long threads of DNA, and in E. intestinalis its almost as though it got a haircut, removing hundreds of genes, but all from the ends of the threads," says Keeling.
Keeling, director of the Centre for Microbial Diversity and Evolution and a member of Beaty Biodiversity Research Centre at UBC, says the discovery provides insights into how genomes evolve, especially in extreme conditions.
INFORMATION:
Keeling is also a scholar with the Canadian Institute for Advanced Research and a Michael Smith Foundation for Health Research Fellow.
END
The horse was domesticated many thousands of years ago and has been hugely important in the development of human civilization. It is hard to overstate its role in agriculture, in transport and communications and even in military operations. More recently, equestrian sports have gained markedly in popularity, so even though the horse has largely been superseded in modern farming and military practice its connection to man remains as close as ever.
Nevertheless, the horse retains at least some aspects of its wild origins. It is clear that horses are frequently subjected ...
As the United States prepares for the upcoming flu season, a group of researchers supported by the National Institutes of Health continues to model how H1N1 may spread.
The work is part of an effort, called the Models of Infectious Disease Agent Study (MIDAS), to develop computational models for conducting virtual experiments of how emerging pathogens could spread with and without interventions. The study involves more than 50 scientists with expertise in epidemiology, infectious diseases, computational biology, statistics, social sciences, physics, computer sciences ...
Researchers from North Carolina State University have developed new software that offers significantly enhanced security for cloud-computing systems. The software is much better at detecting viruses or other malware in the "hypervisors" that are critical to cloud computing, and does so without alerting the malware that it is being examined.
Cloud computing is being hailed as a flexible, affordable way of offering computer resources to consumers. Under the cloud-computing paradigm, the computational power and storage of multiple computers is pooled, and can be shared by ...
Researchers have found that magnetic resonance imaging (MRI) may be sufficient for the routine surveillance of some great vessel (primary blood vessels [e.g., aorta and vena cavae]) stents that are commonly used to treat congenital heart defects (a defect in the structure of the heart and great vessels that is present at birth) in children and young adults, according to a study in the October issue of the American Journal of Roentgenology (www.ajronline.org). MRI is a noninvasive medical test that helps physicians diagnose and treat medical conditions.
"Computed tomography ...
Scientists at the University of Granada have developed a new therapy for the treatment of skin and lung cancer. This therapy involves the use of a suicide coliphage-gene (gene E) that can induce death to cells transfected with it.. Their studies have demostrated that this technique is not only effective in vitro (using tumour cell cultures), but also in vivo through the use of experimental animals in which tumours were induced.
Although further research is required, the results obtained at the University of Granada revealed gene E's intensive antitumour activity, which ...
The prediction of the structure and function of biological macromolecules (i.e., the machinery of life) is of foremost importance in the field of structural biology. Since the elucidation of the three-dimensional structure of DNA (the molecule that carries all genetic information) by Watson and Crick, scientists have strived to decipher the hidden code that determines the evolution of the spatial arrangement of these molecules towards their functional native state. Attempts to follow these structural transitions experimentally and with atomic resolution are hampered by ...
"Yeah, I'm on my way home." "That's funny." "Uh-huh." "What? No! I thought you were – " "Oh, ok." Listening to someone talk on a cell phone is very annoying. A new study published in Psychological Science, a journal of the Association for Psychological Science, finds out why: Hearing just one side of a conversation is much more distracting than hearing both sides and reduces our attention in other tasks.
Lauren Emberson, a psychology Ph.D. candidate at Cornell University, came up with the idea for the study when she was taking the bus as an undergraduate student at the ...
Philadelphia, PA, September 21, 2010 – For the past two decades, cancer therapy has become more sophisticated and effective, resulting in an ever-expanding group of long-term cancer survivors. There is also a growing awareness of the potentially negative effects of cancer treatment on the heart and the management of cardiac disease during and after cancer therapy. In the September/October issue of Progress in Cardiovascular Diseases an international group of experts takes an in-depth look at the ways in which cancer treatment profoundly impacts patients' cardiovascular ...
West Lafayette, IN—September 21, 2010— While most citizens recognize that corruption is "bad," the average citizen is unaware of the benefits enjoyed by politically connected firms, or how common government favors are worldwide. In the U.S., many citizens were outraged at the provision and size of bailouts for "too big to fail" banks. A new study from the journal Financial Management claims that not only does corruption exist in the corporate world, but that political connections are extremely important for corporate success.
Author Mara Faccio studied several thousand ...
The ability to understand emotions is a key ingredient in people who become leaders in groups with no formal authority, a new paper has found.
The findings come through two different studies using commerce students. Study participants were given an emotional ability test as part of the study, as well as a self-analysis of their emotional skills. Then, they organized themselves into small groups or were randomly assigned to small groups and were given a group project to do.
At the end of the project they were asked to identify whom they thought had shown the greatest ...
