Bacteria coat our skin. Few have stinky side effects. Thomas looked at the diet of S. This germ takes up residence in your pits because it loves to dine on a chemical from the apocrine glands. The molecule has no smell on its own. But by the time S. This is a type of sulfurous molecule called a thioalcohol Thy-oh-AL-koh-hol.
The alcohol part ensures that the chemical escapes easily into the air. What does 3M3SH smell like? Thomas gave a group of non-scientists in a local pub a whiff. Then he and asked them what they had smelled. Thomas and his colleagues published their findings in in the journal eLife. Will eating fruits and vegetables prevent cancers? Skip to main content.
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October 5, In the last ten years, however, reports have trickled in from bemused biologists that these receptors, as well as similar ones usually found on taste buds, crop up all over our bodies.
In , bitter taste receptors were found in sperm. The same year Pluznick came across scent receptors in the kidney, biologists at the University of California, San Diego identified sour receptors in the spine. A smattering of papers over the following few years reported sweet taste receptors in the bladder and the gut, bitter taste receptors in the sinuses, airways, pancreas and brain, and scent receptors in muscle tissue.
What are they doing there? As these findings became public, researchers poured over genomic data and reported that low levels of these receptors occurred in almost every tissue in the body. One possible explanation was that they are evolutionary leftovers whose previous functions were lost in time.
However, Pluznick and others have unearthed evidence that, in some tissues at least, they are anything but passive. The kidney is made up of miles of minuscule tubes, twisted into an exquisite lacework. Threaded through these is a system of blood vessels, and in places where these and the kidney's tubes are especially intertwined, water, nutrients and other molecules seep through the walls and pass between the two.
What the blood doesn't need is passed off to the urine forming in the tubes, and what it does have a use for — keeping blood pressure stable, for instance — goes back. If this process stops working the body will soon shut down, poisoned by its own exhaust fumes.
Peering more closely down the microscope at that slice of kidney, Pluznick saw the fluorescent glow was emanating from the macula densa, a group of cells that play a central role in this chemical back-and-forth, sampling the forming urine as it goes by and sending out alerts to adjust the blood filtration rate.
The next step was to figure out what would happen if these receptors were absent in this region of the kidney, using engineered mice that lacked one of scent receptors Pluznick identified in the kidney, called Olfr Tests revealed these mice had kidney problems involving their blood filtration rate and the production of renin, a hormone which stimulates the constriction of blood vessels to increase blood pressure.
Both of these are controlled by the macula densa. Pluznick now began to devote herself full-time to the puzzle. Identifying which chemical "keys" — known as ligands — were binding to the Olfr78 receptor "locks" would help her understand the bigger picture of what the receptor was responding to.
In doing so, her work took her from one weird and wonderful discovery in biology to another: the microbiome. Our bodies contain trillions of bacteria, fungi, and other microorganisms. Those in the human gut fulfil various important functions, such as breaking down certain foods into energy and useful nutrients, suppressing harmful microbes, preventing allergies and assisting the immune system in a number of other ways.
By Gege Li. Some soil-dwelling bacteria like Streptomyces can be toxic. Soil gets its characteristic earthy smell from certain chemicals produced primarily by soil-dwelling bacteria called Streptomyces.
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