00:00For the entirety of human existence, reproduction has relied on a single, strict equation.
00:07Sperm and egg collide, they fuse, and a cell divides.
00:11Scientists at a lab in Utah have successfully bypassed that equation.
00:15This addresses a silent crisis.
00:18Roughly 15% of infertile men produce absolutely no sperm in their ejaculate,
00:23leaving them with zero options for starting a biological family.
00:27These men face a frustrating biological paradox.
00:30They possess the necessary stem cells inside their bodies,
00:34but their internal microenvironment fails to process them into mature reproductive cells.
00:39Before this breakthrough, this specific failure meant a permanent end to any hope for a biological child.
00:45A startup called Paterna Biosciences approached this by removing the physical human body from the process.
00:51Their team extracted dormant sperm-making stem cells from patients and placed them in a laboratory dish.
00:57From there, they successfully grew functional, mature sperm.
01:02Human reproduction is now shifting from an internal bodily function to a controlled external procedure.
01:09A healthy male reproductive system operates like a continuous assembly line.
01:14Stem cells move along the track, have their chromosomes to 23, and sprout tails.
01:19But in severe infertility, the factory floor breaks.
01:23The system pushing cells toward maturity stops.
01:26Rather than trying to surgically or medically repair the patient's internal system,
01:31Paterna's team extracted those raw stem cells to build a new factory on the outside.
01:36Treating deep infertility is shifting away from healing a patient's organs
01:40and toward replacing their function on a laboratory workbench.
01:44The researchers used computer models to calculate the exact chemical signals and instructions
01:49those stem cells require to thrive.
01:52They applied those growth factors to the lab dish,
01:55recreating a healthy microenvironment that precisely mimics the conditions inside a human testicle.
02:00By isolating these specific chemical instructions,
02:04scientists are now the ones delivering the signals that a patient's body cannot.
02:09Controlling actual testicular stem cells poses a major question.
02:13Could we grow reproductive cells using completely ordinary tissue from elsewhere in the body?
02:18That leads directly to in vitro gametogenesis, or IVG.
02:22At the Oregon Health and Science University,
02:25researchers are already pushing this science to human skin.
02:29Researchers take a donor egg, strip out its genetic material,
02:32and insert the nucleus from the skin cell.
02:34After prompting it to shed half its chromosomes and fertilizing it with sperm,
02:39the hybrid cell divides, forming early-stage human embryos.
02:42This offers a direct biological route for same-sex couples to have children
02:47genetically related to both partners.
02:49One partner's skin cells could be reprogrammed into an egg,
02:52and fertilized by the others' naturally-produced sperm.
02:55In vitro gametogenesis removes the rigid biological boundaries
03:00that dictate who can physically create a child.
03:02The clock on this research is moving fast.
03:06Developmental geneticists working in the field
03:08estimate they are as little as seven years away
03:11from creating viable human sex cells entirely from scratch.
03:15On a civilizational scale,
03:17lab-grown eggs could drastically extend the family planning window for women,
03:21providing a potential tool to reverse global population decline.
03:25But these benefits crash immediately into financial reality.
03:29Procedures are expected to cost between $5,000 and $12,000.
03:34Because fertility care is largely uncovered by insurance,
03:37this technology may only be available to the wealthy.
03:40Then there is the matter of safety.
03:42Before clinical trials can ever begin,
03:45scientists must prove that constructing cells outside the body
03:48won't introduce unseen, dangerous genetic mutations into the population.
03:52The technology also makes previously impossible scenarios physically real.
03:57Babies derived from a single person's DNA,
04:00or multiplex babies containing genetic material from three or more adults.
04:05We have to weigh the eradication of absolute infertility
04:09against the reality of engineering outcomes
04:11that completely diverge from natural human biology.
04:14The laboratory is gradually replacing the testicle and the ovary
04:18as the site of human origin.
04:20We are now left to determine the boundaries of that transition.
04:23We're now left to determine the difference between the needs of our sensation.
04:25Here we are at 37 outside ofレاد.
04:25We have anonent of nature of a value.
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