Becca Bressler
Appearances
Radiolab
Everybody's Got One
So in the world of Harvey's analogy here, PP13 is blowing up the grocery store. The placenta produces it. It goes off to some other part of the uterus that the placenta isn't trying to invade.
Radiolab
Everybody's Got One
And while the whole police force is over there dealing with the PP-13, the placenta's digging claws bust through.
Radiolab
Everybody's Got One
But if neither side wins the war, then after nine months, give or take a few weeks... You have a baby. And poof is exactly what it feels like.
Radiolab
Everybody's Got One
Yeah. And then Harvey told us how the placenta, this little alien invader and all its thirsty veins and tendrils and hooks, how it leaves the body.
Radiolab
Everybody's Got One
And they do, like immediately. There's this river of blood fountaining into the placenta that just shuts off.
Radiolab
Everybody's Got One
Yeah, in some sense, I think of it as like the OG parent for the baby. It's one mission is to help that embryo grow into a healthy fetus and deliver a baby. And it's developed this sort of like incredible way of somehow making sure all of its needs are met in such a selfless sort of way that I've started seeing it as the first parent.
Radiolab
Everybody's Got One
I mean, I guess it goes in the garbage most of the time. I feel really sad that I can't meet mine. I think once you know all that it's done for you, I just wish I could meet it.
Radiolab
Everybody's Got One
We got to send that family this podcast. I'm sure we can't know who they are, hip-hop.
Radiolab
Everybody's Got One
And these other scientists in the lab ended up with this thing called a gradient, where the different kinds of cells in the placenta were sort of separated out. They can look at them independently.
Radiolab
Everybody's Got One
Okay, so Harvey says the first thing you have to understand is that that tiny embryo with its little baby placenta cells wrapped around it like a blanket, it is not welcome in the mother's body.
Radiolab
Everybody's Got One
You know, the pregnancy is a little bit genetically the mom, but also a little bit the dad.
Radiolab
Everybody's Got One
Melissa Wilson, geneticist at Arizona State. We need to get rid of not-self.
Radiolab
Everybody's Got One
And so if an embryo just waltzes into a uterus one day without a little placenta blanket around it, the mother's body would gather up a squad of white blood cells, send them out to find it, shred it apart, and kill it.
Radiolab
Everybody's Got One
So the placenta is in the uterus looking around for food. And it does this thing, something kind of tricky, something that when we heard about it actually feels like it's skipping ahead nine months. Harvey says it produces this hormone, HCG, happens to be the hormone that activates pregnancy tests.
Radiolab
Everybody's Got One
Yeah. But this milk is like a snack for the placenta. What it really needs is blood. So at this point, about two weeks into the pregnancy, the placenta goes on the offensive. By now, it's actually latched onto the side of the uterus.
Radiolab
Everybody's Got One
And what you start to see is this push and pull where the placenta keeps digging, digging, digging.
Radiolab
Everybody's Got One
is just getting started. Week five goes by, then week six, week seven, the embryos growing eyes, ears, bones.
Radiolab
Everybody's Got One
Meanwhile, the placenta is digging, digging, digging, trying to get to the blood to get this thing more nutrients. But the placenta just can't break through.
Radiolab
Everybody's Got One
Specifically, one trick called PP13. It's a protein that Harvey says creates a diversion.