字幕表 動画を再生する 英語字幕をプリント IMAGINE IF ANYONE WHO WANTED TO HAVE A CHILD, WHETHER THEY'RE STRAIGHT, GAY, YOUNG, OLD, CANCER SURVIVOR, OR EVEN SINGLE PARENT… COULD CONCEIVE A HEALTHY BABY EASILY? WITH MODERN TOOLS, TECHNOLOGIES, AND THERAPIES ON THE HORIZON, SOME SAY THE END OF INFERTILITY IS IN SIGHT. BUT WILL IT BE A WORLD OF EMBRYO FARMS AND EUGENICS? OR ONE WHERE THE FUNDAMENTAL JOYS OF PARENTHOOD ARE AVAILABLE TO EVERYONE? HOW CLOSE ARE WE TO THE END OF INFERTILITY? INFERTILITY AFFECTS ABOUT 12% OF COUPLES TRYING TO CONCEIVE A CHILD TODAY. AND IT'S A PROBLEM THAT DOESN'T HAVE ONE SIMPLE SOLUTION. - The usual suspects are male factor infertility, tubal factor infertility, ovulation disorders – when a woman doesn't release an egg; unexplained infertility... One of the, probably, newest infertility factors that we are seeing more and more is age factor. People are delaying their fertility and their childbearing for multiple reasons. ON THE MEDICAL SIDE OF THINGS, THERE'S A LONG LIST OF OPTIONS AVAILABLE TO HETEROSEXUAL PATIENTS, DEPENDING ON THEIR DIAGNOSIS, INCLUDING OPTIMIZATION OF INTERCOURSE, HORMONE THERAPY, AND INTRAUTERINE INSEMINATION… And then there is IVF, which is, as we call it, bigger guns. It's more invasive, but also a more successful treatment that we have. IVF STANDS FOR IN-VITRO FERTILIZATION, WHERE EGGS AND SPERM ARE COMBINED IN A LAB, AND THE RESULTING FERTILIZED EMBRYO IS IMPLANTED IN A WOMAN'S UTERUS. - It was a technology that really I think blew people's minds, the idea that we could have reproduction occur outside the body. But these days, It's become part of the natural landscape of human reproduction. BUT FOR SOME COUPLES, IVF WILL ONLY GET THEM SO FAR. - If you're unable to make an egg or sperm, then that means you're unable to use In Vitro Fertilization to have a family. - Infertility is medical. It is the idea that you lack something you need for reproduction. Dysfertility, on the other hand, refers to the social aspect of reproduction. The best examples are gays and lesbians who need, typically, gametes or a surrogate from the other sex in order to help them, and single individuals who might not have a reproductive partner. THAT'S WHY ALL OVER THE WORLD, RESEARCHERS IN LABS LIKE AMANDER CLARK'S BELIEVE THAT DYSFERTILITY DOESN'T HAVE TO BE THE END OF THE STORY. ON THE CUTTING EDGE OF STEM CELL BIOLOGY, THEY'RE DISCOVERING CLUES ABOUT THE CAUSES OF INFERTILITY, AND IN THE PROCESS, MIGHT PAVE THE WAY FOR A NEW METHOD OF REPRODUCTION THAT DOESN'T REQUIRE EGGS OR SPERM AT ALL… AT LEAST UP FRONT. INSTEAD, IT RELIES ON INDUCED PLURIPOTENT STEM CELLS. - Basically, you can take skin cells, injected into with this famous cocktail of transcription factors, and make them into pluripotent stem cells. - Induced pluripotent stem cells are made by first taking a skin punch biopsy, for example. And we will grow cells out of the biopsy in a tissue culture plate, and these cells are called dermal fibroblasts. We need to store them under liquid nitrogen and they can stay here for years and years and years until we're ready to reprogram them. So it takes about three weeks to fill up a plate, and it takes about another three weeks to turn those dermal fibroblasts into induced pluripotent stem cells. Oh, that's a beautiful colony! - You could take some of my skin right now, you could take those adult cells and you could return them to an earlier stage in their development where they can become multiple different kinds of cells. WHAT'S EXCITING IS THAT AMANDER'S TEAM HAS ALREADY PROVEN THAT WE CAN USE THIS METHOD TO CREATE GERMLINE CELLS, THE PRECURSORS TO EGGS AND SPERM. - Forming germline is a really special cell type and it's very hard to make. What my lab was able to show is that it is possible to make germline cells from induced pluripotent stem cells. So how can we take these precursor germ cells that we make in the lab, and coax them to move into the next step in development, which takes us one step closer to making the egg and the sperm cell? AND IF THEY'RE SUCCESSFUL, IT WOULD BE HUGE: POTENTIALLY SETTING THE STAGE FOR THE NEXT REVOLUTION IN REPRODUCTION: IN-VITRO GAMETOGENESIS, OR IVG. RESEARCHERS HAVE ALREADY PROVEN THAT IVG CAN BE SUCCESSFUL IN MICE, SO, IT'S NOT IMPOSSIBLE. BUT HOLD UP! DOESN'T CREATING EGGS AND SPERM OUT OF SKIN CELLS RAISE SOME SERIOUS QUESTIONS ABOUT WHAT REPRODUCTION EVEN MEANS? JUST AS IVF WAS HOTLY DEBATED WHEN IT FIRST ARRIVED ON THE SCENE, IVG HAS SPAWNED SOME CONCERNS. - One is this idea that we'll end up with these huge embryo farms. That instead of producing five or six embryos and choosing one of them, maybe you would produce a thousand embryos, and decide amongst the thousand which to reproduce. And for some people, that's a very alarming idea. It raises the possibility of eugenics, perfectionism, but also this idea that maybe we'll have a huge market for embryos, buying and selling, or have thousands of embryos per individual stored in a freezer or disposed of. THEN, THERE'S WHAT GLENN CALLS THE 'CELEBRITY SCENARIO' TO CONTEND WITH. Imagine, you go to a hotel, and you find that Brad Pitt was staying at that hotel. You're cleaning the hotel and there's some skin of Brad Pitt's left on the bathtub. From that adult cell, you might be able to use in-vitro gametogenesis to derive a sperm or an egg. And the idea would be, you could reproduce and have a child, that is – genetically speaking – Brad Pitt's child, without ever having met Brad Pitt, without ever having talked to Brad Pitt, without him ever consenting to the reproduction. THE BRAD PITT SCENARIO, AS I LIKE TO CALL IT, DOES GIVE US A LOT TO THINK ABOUT AS WE CHANGE OUR DEFINITION OF WHAT IT MEANS TO REPRODUCE. BUT THAT MEANING IS ALREADY CHANGING. AND WITH SO MANY TOOLS ALREADY IN OUR BABY-MAKING TOOLBOX, AND MORE TO COME ONLINE SOON, HOW CLOSE ARE WE TO THE END OF INFERTILITY? - In-vitro gametogenesis and making a gamete, for example, an egg, that we could use for research purposes I believe is about five to 10 years away. The challenge will be translating this work from a research lab into the clinic so that it can be used to help couples overcome infertility. - So, we are nearing the end of many forms of infertility. People who have mitochondrial diseases can use mitochondrial replacement therapies. People who have other diseases might be able to use gene editing. Women who have uterine factor infertility can already use a uterus transplant if it's available in their location. - With the whole IVG thing, that's maybe sounding like a science fiction now. But even the whole IVF was a science fiction 50 years ago. But there is a lot of research going on in that direction. And I do believe that probably in maybe, you know, 30, 40 years, maybe even 10 years, we will have some clinical applications. - And the idea that that which can be imagined in fiction, can become fact within a generation, suggest to me that there's huge numbers of other reproductive revolutions still ahead of us that people still haven't even conceived of yet. ONE THING'S FOR SURE - OUR YOUTUBE CHANNEL IS FERTILE GROUND TO GROW YOUR NERDY KNOWLEDGE. SO BE SURE TO SUBSCRIBE, AND COME BACK FOR NEW STORIES FROM THE FRONTIERS OF SCIENCE. THANKS FOR WATCHING!