字幕列表 影片播放 列印英文字幕 (dreamy music) This is Bertie. He might look like any other cow, but there's one little thing about him that sets him apart from his breed. Bertie has never grown a pair of horns. And that wasn't a fluke of nature. Parts of his DNA were rewritten by this man. Using new tools in gene editing, scientists like him are gaining unprecedented control over the fate of all living things. As technology replaces old jobs, it's also creating new ones. I'm Aki Ito, and I'm here to show you the jobs of the future. (upbeat music) My name is Dan Carlson and I'm a gene editor. Buckle up. The field is changing almost by the day, so new innovations, new techniques, gene-editing technology, it's just gonna improve our lives in a number of ways. Dan works for a biotech startup called Recombinetics here in St. Paul, Minnesota. So this is the embryology lab. He's tackling a problem that's plagued farmers for generations. Most dairy cattle are born with horns, which they can use to hurt each other and their human handlers. Because of that, worldwide, farmers remove horns from millions of dairy calves each year. It's a painful and distressing process for the animals. Dan wants cows to be born hornless and hopes to eliminate the practice of dehorning altogether. What we can do on this microscope here is take the cells that we've engineered and create embryos out of those. (playful music) You might think of Dan as some kind of mad scientist, but he's really the most wholesome guy you could imagine. He's an excellent maker of hamburgers. Which one do you want, Ethan? I want the tastiest one. He's a husband to this lovely woman. You have to eat some of your pizza, bud. And a dad to three adorable kids. Lilly, do you know what your dad does at work every day? He works. He works? Do you know what he does? He kills pigs? I do what? To be clear, one of Dan's other projects involves editing the genes of pigs. In case you were wondering. (tranquil guitar music) Dan's passion for farm animals stems from his childhood growing up on this farm. It's run by his dad, who has a very fitting name. This farm here is where my dad started out farming. I never dreamt that Dan would be a scientist. In high school, it was the time where the genetically modified crops were beginning to be planted. And my dad was one of the early adopters. You could see the difference in the crops immediately. They were taller. They didn't have any problems standing up. And from that moment on, I was like this technology is for real. It can really make a difference. Gene editing themselves is kind of science fiction to me, but I'm very proud of the work that Dan does. I think they were hungry. For Darwin, dehorning cattle has always been his least favorite part of the job. When they get their horns cut off, they holler like crazy, so you know that it ain't a comfortable thing that's happening to them. There are cows that naturally never grow horns, but they're usually used for beef. They can't produce enough milk for dairy farmers. So six years ago, Dan started working on developing hornless dairy cattle. I was interested in trying to solve some of the problems that my dad encountered. Using a gene-editing tool that was discovered less than a decade ago, Dan's team took a dairy cow's cell, cut out the genetic segment that makes the animal grow horns and then swapped in a sequence found in some beef cattle that makes them hornless. Next, his team created an embryo from the edited cell and inserted it into a surrogate mother. Then, they waited for nine nerve-racking months. You're expecting it to come out without any horns or horn buds but you just don't know. Bertie, the world's first cow to be gene edited for hornlessness was born in 2015 in Iowa. Shortly after, he was transferred here to the University of California at Davis. He's incredibly strong. I can see why it would be dangerous to have horns on him. No, that's right. They kind of use their head as their defense. It's natural for them to do that, and obviously when you have a 1,500 pound animal moving his head around like that, it doesn't take much to do some pretty significant damage. Bertie became a dad to six calves in the fall. All of them inherited their father's lack of horns, and one of them happens to be female. In a few years, she's gonna be old enough to produce milk, which scientists are planning to examine. Nolan, do you like cows? I love them. I love their babies the most. Who likes yogurt? Who likes milk shakes? Me. Would you let your kids drink the milk of a gene-edited cow? Of course. Yeah? Yeah. You wouldn't be-- I would purposely buy it if it was on the market. Biologists are now pouring into the field of gene editing, coming out with new applications at dizzying speeds. If it all goes according to plan, much of it will change our lives for the better. But will there be unintended consequences? And how much tinkering with nature is too much? Oh, you're getting some kisses. Our answers will shape the future of Dan's profession. Whether this strain of animals takes off, it's really up to the government and public acceptance. I can't go a lot about those things. I just gotta do my job.