1 00:00:02,040 --> 00:00:07,080 Speaker 1: Welcome to brain stuff from how Stuff Works, Hey, brain Stuff, 2 00:00:07,160 --> 00:00:10,600 Speaker 1: Lauren vogel Bam. Here in Southeast Asia, the Durian is 3 00:00:10,640 --> 00:00:13,760 Speaker 1: called the king of fruits, but not everybody in the 4 00:00:13,760 --> 00:00:18,480 Speaker 1: world bows down to this bulbous, spiny, custardy delicacy. That's 5 00:00:18,640 --> 00:00:21,720 Speaker 1: usually because of the odor. The smell of a ripe 6 00:00:21,800 --> 00:00:25,400 Speaker 1: Daurian has been compared to sweaty socks, road kill, custard, 7 00:00:25,720 --> 00:00:29,720 Speaker 1: rotten eggs, garlic, cheese, a gas leak, and a sewer 8 00:00:29,800 --> 00:00:33,040 Speaker 1: full of rotting pineapples. And it's strong enough that in 9 00:00:33,120 --> 00:00:36,159 Speaker 1: places where it grows, many businesses and public areas have 10 00:00:36,280 --> 00:00:40,159 Speaker 1: pictographic signs up no Duryan, like no smoking, but with 11 00:00:40,159 --> 00:00:42,680 Speaker 1: a spiny ball in the place of the cigarette. But 12 00:00:42,760 --> 00:00:46,440 Speaker 1: still the fruit has its super fans, and now some 13 00:00:46,600 --> 00:00:49,960 Speaker 1: of those super fans, from the National Cancer Center Singapore 14 00:00:50,080 --> 00:00:53,680 Speaker 1: and Duke and US Medical School, along with some financial 15 00:00:53,680 --> 00:00:57,240 Speaker 1: donors who love Durians enough to privately fund study about them, 16 00:00:57,320 --> 00:01:00,800 Speaker 1: have completely mapped the Dairyan genome to find out, among 17 00:01:00,840 --> 00:01:05,160 Speaker 1: other things, why the putrid stench durians. In the study 18 00:01:05,240 --> 00:01:08,520 Speaker 1: published in the journal Nature Genetics, the researchers sequence to 19 00:01:08,520 --> 00:01:11,800 Speaker 1: the genome of a popular and prized daurian variety called 20 00:01:11,880 --> 00:01:14,720 Speaker 1: Mussang King and found its genome is made up of 21 00:01:14,760 --> 00:01:18,040 Speaker 1: around forty six thousand genes, just about double the number 22 00:01:18,040 --> 00:01:20,840 Speaker 1: of genes that compose the human genome. They found the 23 00:01:20,880 --> 00:01:24,520 Speaker 1: plant is closely related to both cotton and cacao. That's right, 24 00:01:24,600 --> 00:01:27,640 Speaker 1: the plant that gives us chocolate. But the researchers were 25 00:01:27,640 --> 00:01:30,560 Speaker 1: really interested in the source of the smell, so in 26 00:01:30,760 --> 00:01:34,360 Speaker 1: snooping around the genome for odor producing compounds, they found 27 00:01:34,400 --> 00:01:36,560 Speaker 1: a class of genes called m g l S that's 28 00:01:36,600 --> 00:01:40,520 Speaker 1: methionin gamma liaises in the leaves, roots, and fruits of 29 00:01:40,600 --> 00:01:44,320 Speaker 1: daurian plants. The researchers found that these genes regulate the 30 00:01:44,360 --> 00:01:48,840 Speaker 1: synthesis of odor producing volatile sulfur compounds or vs cs, 31 00:01:49,320 --> 00:01:52,440 Speaker 1: you know like rotten egg smell. They also discovered that 32 00:01:52,480 --> 00:01:54,960 Speaker 1: in the ripe fruit, the expression of one of these 33 00:01:55,080 --> 00:01:59,440 Speaker 1: VCS expressing genes is about two thousand times stronger than 34 00:01:59,480 --> 00:02:02,760 Speaker 1: another part to the plant in the wild, This aspect 35 00:02:02,880 --> 00:02:06,520 Speaker 1: may be responsible for attracting seed dispersing animals like elephants 36 00:02:06,520 --> 00:02:09,800 Speaker 1: and bats to the Durian fruit. This isn't the first 37 00:02:09,840 --> 00:02:13,680 Speaker 1: research conducted on the durian's unique scent. In a team 38 00:02:13,680 --> 00:02:17,280 Speaker 1: of German researchers identified dozens of chemical compounds that combine 39 00:02:17,320 --> 00:02:20,400 Speaker 1: to create the smell, but that research did not investigate 40 00:02:20,400 --> 00:02:23,920 Speaker 1: the genes behind those compounds. The current research team was 41 00:02:23,960 --> 00:02:26,760 Speaker 1: hoping to make an important medical discovery with the sequencing 42 00:02:26,800 --> 00:02:30,440 Speaker 1: of the Musang king genome. After all, anti cancer drugs 43 00:02:30,440 --> 00:02:32,799 Speaker 1: like taxol derived from the bark of the Pacific u 44 00:02:33,200 --> 00:02:37,200 Speaker 1: save lives every day, and as biodiversity decreases all over 45 00:02:37,240 --> 00:02:39,320 Speaker 1: the world, we need to figure out what we have 46 00:02:39,480 --> 00:02:43,640 Speaker 1: while it's still around. But as Durian enthusiasts, these scientists 47 00:02:43,720 --> 00:02:47,440 Speaker 1: also just wanted to investigate how this quirky and controversial 48 00:02:47,480 --> 00:02:51,000 Speaker 1: plant might be conserved. Besides Mussan king, there are around 49 00:02:51,040 --> 00:02:54,040 Speaker 1: thirty other species of durian, both edible and inedible, in 50 00:02:54,080 --> 00:02:57,200 Speaker 1: the Southeast Asian forests, and some of them are endangered. 51 00:02:57,800 --> 00:03:01,079 Speaker 1: In a press release, co lead author doctor Ben Tian, 52 00:03:01,360 --> 00:03:04,880 Speaker 1: Deputy Director of the National Cancer Center Singapore, wrote, many 53 00:03:04,919 --> 00:03:06,959 Speaker 1: of these other Durian species are in this part of 54 00:03:07,000 --> 00:03:09,560 Speaker 1: the world, and sadly some are endangered due to the 55 00:03:09,600 --> 00:03:13,639 Speaker 1: increasing loss of biodiversity. DNA sequencing is thus an important 56 00:03:13,639 --> 00:03:17,200 Speaker 1: tool to protect the precious information contained in these fascinating 57 00:03:17,240 --> 00:03:25,600 Speaker 1: and important plants. Today's episode was written by Jesselyin Shields 58 00:03:25,600 --> 00:03:28,440 Speaker 1: and produced by Tyler Clang. I've got another podcast called 59 00:03:28,480 --> 00:03:30,840 Speaker 1: food Stuff that explores the science and history of food, 60 00:03:30,880 --> 00:03:33,000 Speaker 1: and we did a whole episode on Durian, so check 61 00:03:33,040 --> 00:03:35,680 Speaker 1: that out if you're still curious, And of course, for 62 00:03:35,760 --> 00:03:38,640 Speaker 1: more on this and lots of other topics about questionable smells, 63 00:03:38,920 --> 00:03:52,560 Speaker 1: visit our home planet, how stuff works dot com.