Speaker 1: Welcome to brain stuff from how Stuff Works, Hey, brain Stuff,
Speaker 1: Lauren vogel Bam. Here in Southeast Asia, the Durian is
Speaker 1: called the king of fruits, but not everybody in the
Speaker 1: world bows down to this bulbous, spiny, custardy delicacy. That's
Speaker 1: usually because of the odor. The smell of a ripe
Speaker 1: Daurian has been compared to sweaty socks, road kill, custard,
Speaker 1: rotten eggs, garlic, cheese, a gas leak, and a sewer
Speaker 1: full of rotting pineapples. And it's strong enough that in
Speaker 1: places where it grows, many businesses and public areas have
Speaker 1: pictographic signs up no Duryan, like no smoking, but with
Speaker 1: a spiny ball in the place of the cigarette. But
Speaker 1: still the fruit has its super fans, and now some
Speaker 1: of those super fans, from the National Cancer Center Singapore
Speaker 1: and Duke and US Medical School, along with some financial
Speaker 1: donors who love Durians enough to privately fund study about them,
Speaker 1: have completely mapped the Dairyan genome to find out, among
Speaker 1: other things, why the putrid stench durians. In the study
Speaker 1: published in the journal Nature Genetics, the researchers sequence to
Speaker 1: the genome of a popular and prized daurian variety called
Speaker 1: Mussang King and found its genome is made up of
Speaker 1: around forty six thousand genes, just about double the number
Speaker 1: of genes that compose the human genome. They found the
Speaker 1: plant is closely related to both cotton and cacao. That's right,
Speaker 1: the plant that gives us chocolate. But the researchers were
Speaker 1: really interested in the source of the smell, so in
Speaker 1: snooping around the genome for odor producing compounds, they found
Speaker 1: a class of genes called m g l S that's
Speaker 1: methionin gamma liaises in the leaves, roots, and fruits of
Speaker 1: daurian plants. The researchers found that these genes regulate the
Speaker 1: synthesis of odor producing volatile sulfur compounds or vs cs,
Speaker 1: you know like rotten egg smell. They also discovered that
Speaker 1: in the ripe fruit, the expression of one of these
Speaker 1: VCS expressing genes is about two thousand times stronger than
Speaker 1: another part to the plant in the wild, This aspect
Speaker 1: may be responsible for attracting seed dispersing animals like elephants
Speaker 1: and bats to the Durian fruit. This isn't the first
Speaker 1: research conducted on the durian's unique scent. In a team
Speaker 1: of German researchers identified dozens of chemical compounds that combine
Speaker 1: to create the smell, but that research did not investigate
Speaker 1: the genes behind those compounds. The current research team was
Speaker 1: hoping to make an important medical discovery with the sequencing
Speaker 1: of the Musang king genome. After all, anti cancer drugs
Speaker 1: like taxol derived from the bark of the Pacific u
Speaker 1: save lives every day, and as biodiversity decreases all over
Speaker 1: the world, we need to figure out what we have
Speaker 1: while it's still around. But as Durian enthusiasts, these scientists
Speaker 1: also just wanted to investigate how this quirky and controversial
Speaker 1: plant might be conserved. Besides Mussan king, there are around
Speaker 1: thirty other species of durian, both edible and inedible, in
Speaker 1: the Southeast Asian forests, and some of them are endangered.
Speaker 1: In a press release, co lead author doctor Ben Tian,
Speaker 1: Deputy Director of the National Cancer Center Singapore, wrote, many
Speaker 1: of these other Durian species are in this part of
Speaker 1: the world, and sadly some are endangered due to the
Speaker 1: increasing loss of biodiversity. DNA sequencing is thus an important
Speaker 1: tool to protect the precious information contained in these fascinating
Speaker 1: and important plants. Today's episode was written by Jesselyin Shields
Speaker 1: and produced by Tyler Clang. I've got another podcast called
Speaker 1: food Stuff that explores the science and history of food,
Speaker 1: and we did a whole episode on Durian, so check
Speaker 1: that out if you're still curious, And of course, for
Speaker 1: more on this and lots of other topics about questionable smells,
Speaker 1: visit our home planet, how stuff works dot com.