olfactory receptors

Linda B. Buck (b. 1947) is the recipient of the 2004 Nobel Prize for Physiology or Medicine, for her work on olfactory receptors. She has significantly added to the understanding of how odours are detected in the nose and transposed into information in the brain.

After obtaining a PhD in immunology, she became an assistant professor in neurobiology at the Harvard Medical School, and established her own research lab. She has been awarded numerous international prizes for her groundbreaking discoveries in relation to the olfactory system.

anonymous asked:

remember that stereochemistry can be every important for aromachemicals, even hydrocarbons!


The R-isomer of carvone (below) smells like mint, while the S-isomer smells like caraway seeds. Fascinating, isn’t it? It shows that the binding sites of the olfactory receptors in our noses are chiral too!

The worst of Megatron’s dreams isn’t a nightmare.

It isn’t a dream of Vos. It isn’t a dream of flames rising ever higher as the towers snap and topple and burn. It isn’t a dream Megatron wakes from with the smell of smoke pricking his olfactory receptors.

It isn’t a dream of Kaon overrun. It isn’t a dream of his city choked by its own smoke, the statue of Megatron at the city gates pulled down by mechs with the Autobot brand welded to their shoulders and chests.

It isn’t even a dream of the Council ascendant, of Megatron and his people battered and beaten and hauled off to the smelters, a failed insurrection crushed as a warning to any mech with dreams of rising above his station.

His worst dream is quiet and pleasant.

He lies on his berth, exhausted from a long day of battle. A young mech, red and blue plating scorched and scratched from the day’s fighting, nestles against him, optics bright.

He wakes still feeling the other’s warmth. He stirs and it fades, leaving him cold.

And he remembers everything.

Genetic Engineering Alters Mosquitoes’ Sense of Smell

In one of the first successful attempts at genetically engineering mosquitoes, HHMI researchers have altered the way the insects respond to odors, including the smell of humans and the insect repellant DEET. The research not only demonstrates that mosquitoes can be genetically altered using the latest research techniques, but paves the way to understanding why the insect is so attracted to humans, and how to block that attraction.

“The time has come now to do genetics in these important disease-vector insects. I think our new work is a great example that you can do it,” says Leslie Vosshall, an HHMI investigator at The Rockefeller University who led the new research, published May 29, 2013 in the journal Nature.

In 2007, scientists announced the completion of the full genome sequence of Aedes aegypti, the mosquito that transmits dengue and yellow fever. A year later, when Vosshall became an HHMI investigator, she shifted the focus of her lab from Drosophila flies to mosquitoes with the specific goal of genetically engineering the insects. Studying mosquitoes appealed to her because of their importance as disease carriers, as well as their unique attraction to humans.

Vosshall’s first target: a gene called orco, which her lab had deleted in genetically engineered flies 10 years earlier. “We knew this gene was important for flies to be able to respond to the odors they respond to,” says Vosshall. “And we had some hints that mosquitoes interact with smells in their environment, so it was a good bet that something would interact with orco in mosquitoes.”

Vosshall’s team turned to a genetic engineering tool called zinc-finger nucleases to specifically mutate the orco gene in Aedes aegypti. They injected the targeted zinc-finger nucleases into mosquito embryos, waited for them to mature, identified mutant individuals, and generated mutant strains that allowed them to study the role of orco in mosquito biology. The engineered mosquitoes showed diminished activity in neurons linked to odor-sensing. Then, behavioral tests revealed more changes.

When given a choice between a human and any other animal, normal Aedes aegypti will reliably buzz toward the human. But the mosquitoes with orco mutations showed reduced preference for the smell of humans over guinea pigs, even in the presence of carbon dioxide, which is thought to help mosquitoes respond to human scent. “By disrupting a single gene, we can fundamentally confuse the mosquito from its task of seeking humans,” says Vosshall. But they don’t yet know whether the confusion stems from an inability to sense a “bad” smell coming from the guinea pig, a “good” smell from the human, or both.

Next, the team tested whether the mosquitoes with orco mutations responded differently to DEET. When exposed to two human arms—one slathered in a solution containing 10 percent DEET, the active ingredient in many bug repellants, and the other untreated—the mosquitoes flew equally toward both arms, suggesting they couldn’t smell the DEET. But once they landed on the arms, they quickly flew away from the DEET-covered one. “This tells us that there are two totally different mechanisms that mosquitoes are using to sense DEET,” explains Vosshall. “One is what’s happening in the air, and the other only comes into action when the mosquito is touching the skin.” Such dual mechanisms had been discussed but had never been shown before.

Vosshall and her collaborators next want to study in more detail how the orco protein interacts with the mosquitoes’ odorant receptors to allow the insects to sense smells. “We want to know what it is about these mosquitoes that makes them so specialized for humans,” she says. “And if we can also provide insights into how existing repellants are working, then we can start having some ideas about what a next-generation repellant would look like.”

You know, I always felt weird about cilantro. I’ve heard people who hate it say it tastes like soap or stinkbugs. And I’ve always thought it did taste kind of like soap and that stinkbugs aren’t so bad because they just smell like cilantro. And boy do I love cilantro.

Anyway, from organic chemistry I know what aldehydes typically smell like. And they’re found in cilantro, soap, and stinkbugs. And, wouldn’t you know it, there’s been research linking cilantro hate to a SNP in a gene coding for an olfactory-receptor that senses aldehydes.

Went and checked my SNPs and sure enough I’m heterozygous for it. One copy to smell it and one copy to not be such a hater, I guess.