St. Louis Encephalitis, Primates, and Flies

Some interesting science stories for you. has an interesting story on the origin and evolution of St. Louis Encephalitis. Turns out a single mutation in the envelope protein is responsible for making the virus pathogenic.

“Recombination is important for disease; it makes novel proteins or genes that the immune system has never seen before,” explains Perkins. “But in this case, it was population dynamics combined with slight changes in the form of point mutations that have been important in the evolution of this virus.”

The virus has an interesting history:

The North American and Haitian strains were passed from common bird hosts such as finches, robins, blue jays, and doves into humans by the Culex mosquito after the virus exploded into a new continent. To time this event, researchers again turned to the genomic code: by determining the rate of mutation in the virus, Perkins found that the division between the South and North American strains happened about 116 years ago. “St. Louis encephalitis is a perfect storm between infected bird hosts coming into a new area and the mosquito vectors transferring the virus to humans,” says Perkins. “It is the North American version of West Nile.”

National Geographic reports on a new paper in Science that looks at the energy costs of climbing versus walking in small primates:

Squirrel monkeys, lemurs, and other tiny species use no more energy climbing vertically than they do walking on the ground.
But large primates, including humans, tend to remain terrestrial for good reason.
“Larger primates have to pay a lot more in terms of energy to climb than to move horizontally,” said study co-author Jandy Hanna, a biological anthropologist now at the West Virginia School of Osteopathic Medicine, who was a graduate student at Duke University at the time of the study.
“It’s a lot of work for them to move around in a three-dimensional environment.”

Science Daily has an interesting story about the differences in protein interactions between humans and fruit flies:

“Scientists have believed for some time that the complexity of an organism’s protein interactions determine its biological complexity, but until now it’s been impossible to put a number on the size of one organism’s interaction network compared to another, as relatively little work has been done to identify and map these interactions.”


The researchers devised a mathematical tool which allows them to predict the total size of an organism’s protein interaction network based on currently available, incomplete data.
The researchers’ next steps will be to make much more detailed predictions based on careful comparisons between species. This will be crucial in order to understand, for example, why some fungal species, such as baker’s yeast are important in the production of bread and beer, while other closely related species cause fungal infections with high mortality rates.

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