Biology Round-up

Some quick hits on some recent scientific advances:

Sound of a Silent Mutation
As you may know, amino acids, the components of proteins, are coded by triplets of nucleic acids. Typically, the third base in the codon allows for some wiggle room, meaning that mutations usually don't result in a change in amino acid, and thus protein function. However, according to the above article, some researchers have apparently found that these "silent mutations" can change the function.

They surmise that this is due to the difference in rate at which the peptide chain is synthesized, resulting in a differently folded protein. That last bit leaves me a bit skeptical, so I guess I'll be more convinced when I see the following: Data showing that the proteins leave at different rates, and data showing differently folded structures.

Bacterial Air Force
In what seems to be a new method, some scientists have created a different method for detecting different types of bacteria. After collecting airborne bacteria, they used an innovative technique for determining what strains are present. Instead of growing colonies, they separated out ribosomal nucleic acids (rRNA) through the use of a fluorescent dye in solution, then ran the dye over a microarray containing complementary strands of around 8000 different bacteria. A computer records the fluorescent spots as positive hits.

A neat idea, although I suppose you could just as easily use the same type of array Tom Meade came up with.

Bacterial Obesity?
I was actually arguing with some people about this on Fark the other day. Not just an excuse for being overweight, some scientists found that the level of bacteria in your digestive system may be related to obesity, though they can't speculate which direction the relationship would go.

Complex polysaccharides in your diet are broken up by enyzmes provided by bacteria in your gut. By breaking the sugars up, your body has access to their energy (and thus, more calories from the food you eat). The idea is that the two different types of bacteria in your system allow for different rates of metabolism. The research suggests that higher levels of bacteriodetes and lower levels of firmicutes.

Incidentally, there were two studies associated with this: One on humans, the other on mice. If you're curious, I have the mouse paper.