September 5, 2013 • 23 mins
Microchimerism: The Mother Inside You: Does a mother retain cells from her child? Does the child retain cells form the mother? In this episode of Stuff to Blow Your Mind, Robert and Julie introduce you to the fantastic world of microchimerism.
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Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind from how Stuff
Works dot Com. Yea, Hey, welcome to Stuff to Blow
your Mind. My name is Robert Lamb and I'm Julie Douglas. Julie.
We often think about ourselves as as a whole, and
we've we've discussed that before in the past, and sort
of the fallacy that we think of ourselves as this
(00:24):
one body, this one autonomous thing, but of course we
are also a host of smaller creatures living inside us.
You can say, you can also go far to say
that our our cellular communities are nothing more than than
just that communities of individuals that make up this whole.
And in this episode of stuff Will in your mind,
we're gonna throw another log onto that fire that illuminates
(00:46):
the the multiple aspects of who we are. That's right.
It is the chimera, which is this idea that comes
from Greek mythology. We're talking about a fire breathing creature
that was part serpent, part lion, and part goat. And
in many ways, when we talk about being host and
and having some sort of micro biome in us, that
(01:09):
perhaps gaming the way that we work physically and mentally,
we are these kind of part line goat Chimera. Yeah.
According to Homer, Um it just had the body of
the gigantic goat, the hind parts of the serpent, the
head of a lion, other depictions. You see, it is
having head of all three. Really, it's kind of train
wreck of a monster. It's not it's not not the
most elegant. Uh. It was said to be the progeny
(01:31):
of two other monsters, um a kidney beautiful woman up top,
serpent down below, and Typhon, which is a nebulous gigantic
form composed of hundreds of dragons, heads and serpent, arms
and legs, breathe fire and love. And it was created
by Gaya after the defeat of the Titans to assail
the forces of the gods. And in the Chimera had
all these monsters siblings, including Cerebus, the Ninian Lion, the Hydra,
(01:52):
and the Sphinx. Is eventually slain by Bellerophon Astride the Pegasus,
and in medieval already comes to symbolize the complex na
nature of evil. Okay, and we we wanted to bring
up the Chimera in both its mythological form and in
the form of animals because we're going to get to it.
But there's some really cool things going on on a
celegular level that sort of brings into question who we are.
(02:15):
We always bring this up, like, am I really me?
Am I? Parts of me? Um? What is mean? What's this?
My brain and my body? Am I a brain? Body?
Am I the me that I think I am? Or
am I to me that exists under the surface of
conscious thought? Well? Or am I the me that is
really accumulation of actually other people in other people's cells?
How could that be? Yes, we'll find out. But first
(02:38):
let's talk about some naturally occurring chimeras. We're talking about slime, mold,
and corals. Those are far less ominous than the fire
breathing kind, right and um. Chimeric can also refer to
an animal that has two or more different sets of
genetically distinct cells working together. So we have a couple
of man made examples. One is a pig that researchers
(03:01):
at the Mayo Clinic in Minnesota had created a pig
with human blood pumping through its veins, and some of
the cells merged together, creating pig human cell hybrid cells. Here.
So what we're talking about is this idea that you
can have an experiment that could give scientists bet our
understanding of how viral infections can pass from one animal
(03:23):
to humans, like HIV. It's not just like, hey, let's
cross a pig's blood with a humans blood and have
some fun here, you know. It kind of sounds like
it's a way to to create a ready source of
human blood and then you just mark the pigs in
when it's time for a transfusion. That would work too. Yeah,
it's kind of monstrous on all fronts. But I mean,
but again, we get into this idea that we're dealing with,
(03:46):
this initial idea that chimera as a monster, that any
kind of form that involves bits of others is a hybrid,
and it's weird and it's gross and probably against God's
natural order. But it's we discussing here. Hybrids do occur
within the natural limits of life, and in a sense,
we are all chimeras. It's right, micro chimers, which we'll
(04:06):
talk about in a moment. But I wanted to bring
up this particularly uh pure form of chimera in the
form of humans. And uh, this became known because in
a woman named Jane found out that she needed a
kidney transplant. An amazing story, all right, So she has
(04:27):
her son, she has three sons, and uh, they give
some blood samples to see if she would be a
good match to be a kidney downer. Well what comes
back is that, okay, um, what you know, miss Jane
or whatever your full name is, because that's never actually
told obviously for her privacy. But what comes back is,
miss Jane, we want to tell you that you could
(04:48):
not possibly be the biological mother of these two of
your three sons, which to her is sort of like,
what are you talking about? Because that it either means oh,
I'm not who I think I am or the children
were swapped out in the hospital. You can just imagine
the various scenarios that would roll around in your head
and wrestle with each other when the doctors telling you that, yeah,
(05:09):
and she's saying, no, I'm the biological mother these children.
Trust me. I had them. They came out of my uterus.
I have this memory of it. And they keep saying, well,
are you sure you know? Maybe they were switched at birth?
And it took the researchers two years to figure this out.
But Margot Crestfall, she was a daughter. She is a
doctor at Beth Israel Deaconess Medical Center in Boston figured
(05:32):
out that Jane is a chimera, a mixture of two individuals,
and what we're talking about are non identical twin sisters
who fused in the womb and grew into a single body. Yes,
she dwight shrewded her twin. Well, it's it's almost crazier
than that. It's like, it's not just like she be.
Those two people became one, you know. It's like it's
(05:54):
like the fly Jeff Goldbloom in a telepod with a fly,
and they emerged, the one being on the other end,
essentially a chimera. And here we have in the telepod
of the womb, these two individuals merged together and become
a single organism, a single individual. Yes, so I mean
she is She's technically a tetra game medic chimera, and
(06:16):
that is a person whose body is made up from
two genetically distinct lines of cells derived from a total
of four gamme eats, eggs, and sperm. So the cells
from only one twin have come to dominate and Jane's blood,
so the tissue used in the tissue typing in the
test for her kidney. That's what we're talking about here.
In her other tissues, including her ovaries, cells of both
(06:39):
types of lived alongside each other. And that accounts for
the genetics of her three sons, because one came from
an egg derived from the twin who cells dominate Jane's blood,
while the two brother the other two brothers came from
eggs derived from the other twin cells. Wow. So it's
so even though one of the twins ended up being
dominant in the individual, the other twin managed to have children.
(07:03):
Like that's just like almost almost like a ghostly sense,
almost like from beyond the grave. Well, that's what's so
amazing about this, this idea that you could carry with
you someone else's cells and that Yeah, there's just this
ghostly like sort of association that that would be informing
also your children, your children's genetics. Uh so that that
(07:26):
is an extreme case of this. Imagine your your siblings
and you both have the same mother, but you have
two different biological mothers, but those two biological mothers are
the same mother. It. Wow, it's really confusing. It's a
bit of a head trip. But now um ivf in
vitro fertilization increases the odds of having for tunnel twins
(07:49):
about thirtyfold and is also associated with an increased risk
of chimera. So it may not be I mean, they
don't have a ton of research on on this so far,
but it may not just be so crazy going forward,
since IVF has been a pretty good option out there
for a couple of decades. Now. Yeah, but this is
(08:11):
an extreme example of cells dominating your body. But it
turns out that all of us have cells from someone
else hanging out, which seems like an incredible statement, but
it is true. And in this we're getting into the
realm of microchimerism. Yeah. So this is when you possess
a small number of cells in your body that are
not genetically your own. And this was first noticed in
(08:32):
nine when a researcher at Stanford University found a few
cells with Y sex chromosomes and a pregnant woman's blood
and those cells had to have come from her son
since women have only X chromosomes. She had male chromosomes
in her body even though she's a pregnant female, right,
(08:52):
So that that was the first inkling that something was
going on. Um, so it turns out that all pregnant
women carry some these are called fetals els by the way,
and DNA. Up to six percent of the free floating
DNA in the mother's blood plasma comes from the fetus,
and after the baby is born, those numbers plummet, but
some cells remain and they actually just don't hang out there.
(09:13):
They they do things in the body. And we'll talk
a little bit more about that. Yeah, there's a wonderful
quote in this New Scientists article by Nancy Shoot Beyond Birth,
and it goes as follows. She says, mother and child
are engaged in a silent chemical conversation throughout pregnancy, with
bits of genetic material and cells passing not only from
mother to child, but also from child to mother. That's
(09:35):
right in that two way street is the pacenta, right um.
The pacenta is an organ it's built of cells from
both the mother and the fetus, and it serves just
as a reminder for everybody as a conduit for the
exchange of nutrients, gases, and waste. And so it's porous,
and so you do have the cells um from from
mother and child passing between each other. That's one of
(09:55):
the ways that you can pass cells to each other,
kind of a cellular backwash. I like that. Yeah, so
you're backwash. After cells crossover, some get rounded up and
killed by the new host immune system, but some of
them take root in the body. They burrow into the heart, liver, kidneys,
spleen skin, pancreas, gall bladdering testines, among other places. They're
(10:17):
kind of like squatters, really like they are clearly and
not supposed to be there. Police round up the ones
they can, but communities begin to take root in certain
you know, abandoned buildings and back alleys. Yeah, and some
of them become really productive members of body society. And
this will discuss somebody not um Now. The fetal cells
can also be passed through mother to infant, through nursing,
(10:41):
and also through transfusions and transplants. We're talking about bone
marrow transplants and organ transplants, and that sort of brings
up into question, you know, well, how do these cells
figure into someone who's not even related to the person
who you know, the organ was transplanted in. And we
cannot answer these questions right now. In fact, this discovery
(11:03):
of microchimerism actually brings up a lot more questions than answers.
But it's pretty fascinating stuff. Let's take a quick break
and when we get back, we're going to talk about
how those fetal cells hang out in your body and
what they do. All right, we're back. Microchimerism. It's pretty nutty,
(11:30):
it yeah. In fact, last year it was found that
male DNA was discovered in the female brain, and this
led everybody to understand that fetal cells are able to
cross the blood brain barrier. Now, this is that that
sort of membrane that keeps out sort of the bad
things that make sure that you don't get toxic chemicals
that are traveling to your brain and and messing up
(11:52):
the works in there um. But this fetal cell being
able to cross the blood brain barrier was found in
Researchers at the Department Biochemistry at the University of Alberta
examined brain autopsy specimens from fifty nine women. They had
died between the ages of thirty two and a hundred
and one. Now, male microcomerism, as it's called in this case,
(12:14):
was detected in sixty three percent of the subjects and
was distributed in multiple brain regions and was potentially persistent
throughout the human lifespans. Of the sixty percent of the subjects,
the oldest female in whom male fetal DNA was detected
in the brain was ninety four years old. Now this
is kind of a huge thing because they had known
(12:35):
that had migrated to different parts of the body, but
they did not know what it was doing in the
brain and if it even acted on the brain, and
that is still a big question mark. But they have
looked at Alzheimer's disease because they know that it's more
common in women who have had multiple pregnancies, and they
thought that they would find that the number of fetal
sales would be a lot greater in women with Alzheimer's
(12:58):
compared to those who had no evidence for any sort
of neurological disorders or disease. But this is the weird
thing that the opposite was true of what they thought
was going to happen. There were fewer fetal derived cells
and women with Alzheimer's. So they're still trying to figure
out what sort of connection that might have. And you know,
long term, there might be some sort of information about
(13:18):
how those how those cells act on the brain, and
you know, you have to also consider that in animal
studies that microchimerate cells were found in maternal brains where
they became nerve cells, it became active members of that
brain society, suggesting that they might have a functionality integrated. Now,
of course, in all this you have to avoid the
(13:40):
temptation to fall into a magical understanding of what's happening.
When when we were researching this, I kept finding people
talking about some of these studies on message boards and
getting a little sentimental and at times a little goofy
about what it meant. Uh. And certainly you see that
even with with ideas of organ transplants and limb transplants
and mean sort of the idea that you know, go
(14:01):
back to the little horror movie with Michael Caine. You
get a hand transplanted onto your body and it's the
hand of a criminal, and suddenly you're gonna do criminal
things because it's the criminal's body part, that's the criminals hand,
and now it's part of you. So you have to again,
you have to put that out of your head. Um.
And there's plenty of weird, almost magical seeming stuff that's
going on anyway, without bringing all of that nonsense and
(14:24):
the equation. It's true, and you know, at some level though,
it is symbolic and it's kind of nice to think that,
you know, your mom is always carrying a bit of
you around, and you're always carrying around some of your mom.
But then but but again, it's just it's selves, it's
not it sells. But here's this just a complicated Like
there's a little her in your flesh pocket on your side,
and she's looking up at you like telling you to
(14:45):
eat your piece. Totally is right now my flesh pocket. Thanks, Yeah,
hey mom um. So here's here's something to complicated. There's
a possibility that sells from an older sibling residing in
the mother may find their way back across the placenta
to a younger sibling. Now that's where it just gets
(15:06):
kind of gross. Like, here's the weird thing, Like, it's
very possible that that I have not only my mom
cells floating around, but my brothers and my daughters. Which
is fine, I mean, obviously it's all working out. But
with your daughter, I mean obviously there's a stronger connective.
But you're you've discussed before how you and your brother
are kind of different organisms, right, I mean you're rather different. Well, yeah,
(15:29):
of course we're different in many ways. But it is
kind of interesting to me as at the second born.
It's always like, man, seriously, you always get like, you know,
second banana hand me down cells, right, thanks a lot.
Uh No, twins, of course, identical twins can also exchange
micro comeric cells through the sheriff of sentence, so us
(15:50):
I don't think anything that's shocking, especially since we've already
stablished they can merge together into one organism. Yeah, you know,
I don't put anything past them, exactly. You gotta watch
out for the twins. They'll do it before you're born.
If there are any twins out there listening, don't do
it later. So much hard to absorb each other or
across cells. Absorb each other or across cells. I mean,
both are a little more difficult and a little more
(16:10):
problematic if you do it as adults. It's true outside
the womb, that is, there's a menial logistics there. Um.
So here's some also interesting thing. There's evidence for competition
between cells from from grandmother in infant within the mother. Yeah.
So that's where it gets a little dicey, and that's
when we start to talk about autoimmune issues. Yeah, because
we have. One of the problems with the autoimmune situation
(16:32):
is that there's the theory is that you have essentially
alien cells in the body. In the immune system detects
alien cells, they're going to fight against them in the
same way that they would have destroyed a number of
them immediately following the birth of the child. So you
get that, you know, the problem of an autoimmune defense
network attacking the body itself and all the complications that
(16:55):
arise from that. Yeah, I mean because some autommune diseases,
which current women three times more than in men, are
thought to be associated with this problem, right, this sort
of they're not assimilating, right, um, the Civil War in
the Yeah, they're trying to figure out like why are
you here? Should you be here? Um? And that's when
you see sort of things like multiple multiple sclorious as
(17:15):
being exacerbated by this issue of fetal cells. Now, the
good news is that, um, these fetal cells can kind
of act like stem cells depending on where they are, Uh,
they can actually help to repair damage tissue. And they're
essentially a transplant of younger, healthier cells in depleted organs,
(17:37):
So they might help protect against certain types of cancer.
So women with breast cancer, for instance, they generally have
lower levels of microclimerrism than women who don't develop disease,
and the suggests a possible role for fetal cells and
helping to detect and destroy tumors because if you think
about it, uh, those microclimeric cells from a pregnancy, they're
(17:58):
recognized by the mom's immune system is belonging to the
mother since they're genetically half identical to the mother, so
they get a pass. So they're they're sort of foreign
to the immune system, but you know, because of the
father's contribution. But they also this is the idea, they
may prime the immune system to be alert for cells
(18:19):
that are similar to the self but with genetic differences.
So the idea is that having the presence of microchlimeric
cells and the body could kind of ferret out cancer
cells and then stem the growth of any tumors. Sort
of like, hey, we're on the alert for you, but
we're also and you're fine, you get a pass, but
these other guys they're not passing the test. So sometimes
(18:43):
hand me down. That stuff is really good stuff. That's
the thing. Sometimes you can really make something out of it. Yeah,
I mean, it's really cool and Nancy shoot, you had
mentioned before in her Beyond Birth article says that fetal
cells also appeared to migrate to injury sites and have
been found in patients with thyroid and liver damage where
they had morphed into organ cells. Wow, so like you can, Yeah,
(19:03):
you can, on a very soular level, you can get
into this idea that my daughter is healing me, my
my my son is healing my body well. And it's
interesting that you say that because there was one account
I can't remember which article, but one of them had
said that there was someone who was going through cancer
treatments and they kept that in mind. My son is
helping to heal me through this. His cells are combating
(19:25):
the cancer cells. And yes, there's a bit of magical
thinking to that, but it's sort of lovely. Yeah, just
don't let it fill into like full on cannibalism, because
I'd be like, I'm feeling at they're on a little
thick here. But I bet if I ate the kid's arm,
then I maybe get a replenishment. It won't work. Messy defects. Okay. Yeah, Um,
(19:48):
so of course we have to to start thinking about
this in a future sense and One of the ways
that researchers and scientists are is to actually look at dogs,
because it turns out microchimerism is present in some dogs,
and now makes setting the condition a lot easier because
you're talking about lifespans ten to twenty years as opposed
to seventy eighty years. So they begin to kind of
(20:10):
look at what that might mean, um, to have these
cells acting like stem cells, or even acting against the museum,
acting against museums, acting about against the immune system, and
then how does this affect the world of human cloning. Well,
it's not as straightforward as we thought, right, yeah, because
it's it's one thing. Because again, we we have this
(20:31):
this notion that we get in our heads that that
I am this one product and if you distole me
down on these cells, on this DNA, on this person,
and then if we can just recreate that data, then
we can recreate, at least in a bodily sense, we
can recreate ourselves. But now you're having to take into account.
I mean, we've discussed, um, you know, all the microbes
(20:51):
that live inside us, and now we have to take
into account different cellular communities from other individuals that make
up who we are, how do you replicate that in
a awning scenario? Right, and not to mention the microbiota
that exists within everyone that is also again influencing how
we moved through the world and what sort of diseases
we may or may not get. Also have the genetics, right, Yeah, Well,
(21:15):
it's like with with cloning. It's um it reminds me
of the movie The Boys from Brazil based on the book,
where you had a plot to clone Hitler and it's
the plot really has a has some fun with the
idea of well, you would have to not only have
a genetic duplicate, you would have to then recreate all
the circumstances that made that person who they were. And
(21:36):
uh in the film sort of operates on the idea that, well,
the genetic side is simple to genetic side is just
pretty straightforward. But it's that conditioning that's where the problem lies.
But we're saying more and more that the genetic side
of things, the cellular side of things is almost equally
complicated if you were actually trying to replicate an individual. Right,
So this idea that we're just unique and we're just
(21:58):
sort of preset with this program at birth, it's following
away away, because now we all realize that we really
truly are chimeras. Yeah, an innocence kind of ephemeral, I mean,
rather ephemeral. Yeah, all right, I just checked my pocket
of flesh and mom says it's time to wrap it up. Okay,
all right, well, uh well pocket of flesh mom, or
we will call it an episode then. But we'd love
(22:21):
to hear from all of you guys and gals out there.
What do you think about this information? Um? How does
it make you think about your relationships with with your parents,
with your children, with strangers, you know, sibling, your sibling,
you know? How does it make you feel that your older,
younger brother maybe a part of who you are on
a solar level? Does that creep you out? Or does
(22:42):
it give you hope? I don't know? And then how
do you and then you know, to what extent do
you draw thin magical interpretations of this into your indual world?
Few we'd love to hear from you. You You can find
us in all the normal places Stuff to blow your
mind dot com. That's the mothership, that's where we put
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(23:03):
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Show and you can always drop us a line at
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this and thousands of other topics, Is it how stuff
Works dot com
Welcome to Stuff to Blow Your Mind from how Stuff
Works dot Com. Yea, Hey, welcome to Stuff to Blow
your Mind. My name is Robert Lamb and I'm Julie Douglas. Julie.
We often think about ourselves as as a whole, and
we've we've discussed that before in the past, and sort
of the fallacy that we think of ourselves as this
(00:24):
one body, this one autonomous thing, but of course we
are also a host of smaller creatures living inside us.
You can say, you can also go far to say
that our our cellular communities are nothing more than than
just that communities of individuals that make up this whole.
And in this episode of stuff Will in your mind,
we're gonna throw another log onto that fire that illuminates
(00:46):
the the multiple aspects of who we are. That's right.
It is the chimera, which is this idea that comes
from Greek mythology. We're talking about a fire breathing creature
that was part serpent, part lion, and part goat. And
in many ways, when we talk about being host and
and having some sort of micro biome in us, that
(01:09):
perhaps gaming the way that we work physically and mentally,
we are these kind of part line goat Chimera. Yeah.
According to Homer, Um it just had the body of
the gigantic goat, the hind parts of the serpent, the
head of a lion, other depictions. You see, it is
having head of all three. Really, it's kind of train
wreck of a monster. It's not it's not not the
most elegant. Uh. It was said to be the progeny
(01:31):
of two other monsters, um a kidney beautiful woman up top,
serpent down below, and Typhon, which is a nebulous gigantic
form composed of hundreds of dragons, heads and serpent, arms
and legs, breathe fire and love. And it was created
by Gaya after the defeat of the Titans to assail
the forces of the gods. And in the Chimera had
all these monsters siblings, including Cerebus, the Ninian Lion, the Hydra,
(01:52):
and the Sphinx. Is eventually slain by Bellerophon Astride the Pegasus,
and in medieval already comes to symbolize the complex na
nature of evil. Okay, and we we wanted to bring
up the Chimera in both its mythological form and in
the form of animals because we're going to get to it.
But there's some really cool things going on on a
celegular level that sort of brings into question who we are.
(02:15):
We always bring this up, like, am I really me?
Am I? Parts of me? Um? What is mean? What's this?
My brain and my body? Am I a brain? Body?
Am I the me that I think I am? Or
am I to me that exists under the surface of
conscious thought? Well? Or am I the me that is
really accumulation of actually other people in other people's cells?
How could that be? Yes, we'll find out. But first
(02:38):
let's talk about some naturally occurring chimeras. We're talking about slime, mold,
and corals. Those are far less ominous than the fire
breathing kind, right and um. Chimeric can also refer to
an animal that has two or more different sets of
genetically distinct cells working together. So we have a couple
of man made examples. One is a pig that researchers
(03:01):
at the Mayo Clinic in Minnesota had created a pig
with human blood pumping through its veins, and some of
the cells merged together, creating pig human cell hybrid cells. Here.
So what we're talking about is this idea that you
can have an experiment that could give scientists bet our
understanding of how viral infections can pass from one animal
(03:23):
to humans, like HIV. It's not just like, hey, let's
cross a pig's blood with a humans blood and have
some fun here, you know. It kind of sounds like
it's a way to to create a ready source of
human blood and then you just mark the pigs in
when it's time for a transfusion. That would work too. Yeah,
it's kind of monstrous on all fronts. But I mean,
but again, we get into this idea that we're dealing with,
(03:46):
this initial idea that chimera as a monster, that any
kind of form that involves bits of others is a hybrid,
and it's weird and it's gross and probably against God's
natural order. But it's we discussing here. Hybrids do occur
within the natural limits of life, and in a sense,
we are all chimeras. It's right, micro chimers, which we'll
(04:06):
talk about in a moment. But I wanted to bring
up this particularly uh pure form of chimera in the
form of humans. And uh, this became known because in
a woman named Jane found out that she needed a
kidney transplant. An amazing story, all right, So she has
(04:27):
her son, she has three sons, and uh, they give
some blood samples to see if she would be a
good match to be a kidney downer. Well what comes
back is that, okay, um, what you know, miss Jane
or whatever your full name is, because that's never actually
told obviously for her privacy. But what comes back is,
miss Jane, we want to tell you that you could
(04:48):
not possibly be the biological mother of these two of
your three sons, which to her is sort of like,
what are you talking about? Because that it either means oh,
I'm not who I think I am or the children
were swapped out in the hospital. You can just imagine
the various scenarios that would roll around in your head
and wrestle with each other when the doctors telling you that, yeah,
(05:09):
and she's saying, no, I'm the biological mother these children.
Trust me. I had them. They came out of my uterus.
I have this memory of it. And they keep saying, well,
are you sure you know? Maybe they were switched at birth?
And it took the researchers two years to figure this out.
But Margot Crestfall, she was a daughter. She is a
doctor at Beth Israel Deaconess Medical Center in Boston figured
(05:32):
out that Jane is a chimera, a mixture of two individuals,
and what we're talking about are non identical twin sisters
who fused in the womb and grew into a single body. Yes,
she dwight shrewded her twin. Well, it's it's almost crazier
than that. It's like, it's not just like she be.
Those two people became one, you know. It's like it's
(05:54):
like the fly Jeff Goldbloom in a telepod with a fly,
and they emerged, the one being on the other end,
essentially a chimera. And here we have in the telepod
of the womb, these two individuals merged together and become
a single organism, a single individual. Yes, so I mean
she is She's technically a tetra game medic chimera, and
(06:16):
that is a person whose body is made up from
two genetically distinct lines of cells derived from a total
of four gamme eats, eggs, and sperm. So the cells
from only one twin have come to dominate and Jane's blood,
so the tissue used in the tissue typing in the
test for her kidney. That's what we're talking about here.
In her other tissues, including her ovaries, cells of both
(06:39):
types of lived alongside each other. And that accounts for
the genetics of her three sons, because one came from
an egg derived from the twin who cells dominate Jane's blood,
while the two brother the other two brothers came from
eggs derived from the other twin cells. Wow. So it's
so even though one of the twins ended up being
dominant in the individual, the other twin managed to have children.
(07:03):
Like that's just like almost almost like a ghostly sense,
almost like from beyond the grave. Well, that's what's so
amazing about this, this idea that you could carry with
you someone else's cells and that Yeah, there's just this
ghostly like sort of association that that would be informing
also your children, your children's genetics. Uh so that that
(07:26):
is an extreme case of this. Imagine your your siblings
and you both have the same mother, but you have
two different biological mothers, but those two biological mothers are
the same mother. It. Wow, it's really confusing. It's a
bit of a head trip. But now um ivf in
vitro fertilization increases the odds of having for tunnel twins
(07:49):
about thirtyfold and is also associated with an increased risk
of chimera. So it may not be I mean, they
don't have a ton of research on on this so far,
but it may not just be so crazy going forward,
since IVF has been a pretty good option out there
for a couple of decades. Now. Yeah, but this is
(08:11):
an extreme example of cells dominating your body. But it
turns out that all of us have cells from someone
else hanging out, which seems like an incredible statement, but
it is true. And in this we're getting into the
realm of microchimerism. Yeah. So this is when you possess
a small number of cells in your body that are
not genetically your own. And this was first noticed in
(08:32):
nine when a researcher at Stanford University found a few
cells with Y sex chromosomes and a pregnant woman's blood
and those cells had to have come from her son
since women have only X chromosomes. She had male chromosomes
in her body even though she's a pregnant female, right,
(08:52):
So that that was the first inkling that something was
going on. Um, so it turns out that all pregnant
women carry some these are called fetals els by the way,
and DNA. Up to six percent of the free floating
DNA in the mother's blood plasma comes from the fetus,
and after the baby is born, those numbers plummet, but
some cells remain and they actually just don't hang out there.
(09:13):
They they do things in the body. And we'll talk
a little bit more about that. Yeah, there's a wonderful
quote in this New Scientists article by Nancy Shoot Beyond Birth,
and it goes as follows. She says, mother and child
are engaged in a silent chemical conversation throughout pregnancy, with
bits of genetic material and cells passing not only from
mother to child, but also from child to mother. That's
(09:35):
right in that two way street is the pacenta, right um.
The pacenta is an organ it's built of cells from
both the mother and the fetus, and it serves just
as a reminder for everybody as a conduit for the
exchange of nutrients, gases, and waste. And so it's porous,
and so you do have the cells um from from
mother and child passing between each other. That's one of
(09:55):
the ways that you can pass cells to each other,
kind of a cellular backwash. I like that. Yeah, so
you're backwash. After cells crossover, some get rounded up and
killed by the new host immune system, but some of
them take root in the body. They burrow into the heart, liver, kidneys,
spleen skin, pancreas, gall bladdering testines, among other places. They're
(10:17):
kind of like squatters, really like they are clearly and
not supposed to be there. Police round up the ones
they can, but communities begin to take root in certain
you know, abandoned buildings and back alleys. Yeah, and some
of them become really productive members of body society. And
this will discuss somebody not um Now. The fetal cells
can also be passed through mother to infant, through nursing,
(10:41):
and also through transfusions and transplants. We're talking about bone
marrow transplants and organ transplants, and that sort of brings
up into question, you know, well, how do these cells
figure into someone who's not even related to the person
who you know, the organ was transplanted in. And we
cannot answer these questions right now. In fact, this discovery
(11:03):
of microchimerism actually brings up a lot more questions than answers.
But it's pretty fascinating stuff. Let's take a quick break
and when we get back, we're going to talk about
how those fetal cells hang out in your body and
what they do. All right, we're back. Microchimerism. It's pretty nutty,
(11:30):
it yeah. In fact, last year it was found that
male DNA was discovered in the female brain, and this
led everybody to understand that fetal cells are able to
cross the blood brain barrier. Now, this is that that
sort of membrane that keeps out sort of the bad
things that make sure that you don't get toxic chemicals
that are traveling to your brain and and messing up
(11:52):
the works in there um. But this fetal cell being
able to cross the blood brain barrier was found in
Researchers at the Department Biochemistry at the University of Alberta
examined brain autopsy specimens from fifty nine women. They had
died between the ages of thirty two and a hundred
and one. Now, male microcomerism, as it's called in this case,
(12:14):
was detected in sixty three percent of the subjects and
was distributed in multiple brain regions and was potentially persistent
throughout the human lifespans. Of the sixty percent of the subjects,
the oldest female in whom male fetal DNA was detected
in the brain was ninety four years old. Now this
is kind of a huge thing because they had known
(12:35):
that had migrated to different parts of the body, but
they did not know what it was doing in the
brain and if it even acted on the brain, and
that is still a big question mark. But they have
looked at Alzheimer's disease because they know that it's more
common in women who have had multiple pregnancies, and they
thought that they would find that the number of fetal
sales would be a lot greater in women with Alzheimer's
(12:58):
compared to those who had no evidence for any sort
of neurological disorders or disease. But this is the weird
thing that the opposite was true of what they thought
was going to happen. There were fewer fetal derived cells
and women with Alzheimer's. So they're still trying to figure
out what sort of connection that might have. And you know,
long term, there might be some sort of information about
(13:18):
how those how those cells act on the brain, and
you know, you have to also consider that in animal
studies that microchimerate cells were found in maternal brains where
they became nerve cells, it became active members of that
brain society, suggesting that they might have a functionality integrated. Now,
of course, in all this you have to avoid the
(13:40):
temptation to fall into a magical understanding of what's happening.
When when we were researching this, I kept finding people
talking about some of these studies on message boards and
getting a little sentimental and at times a little goofy
about what it meant. Uh. And certainly you see that
even with with ideas of organ transplants and limb transplants
and mean sort of the idea that you know, go
(14:01):
back to the little horror movie with Michael Caine. You
get a hand transplanted onto your body and it's the
hand of a criminal, and suddenly you're gonna do criminal
things because it's the criminal's body part, that's the criminals hand,
and now it's part of you. So you have to again,
you have to put that out of your head. Um.
And there's plenty of weird, almost magical seeming stuff that's
going on anyway, without bringing all of that nonsense and
(14:24):
the equation. It's true, and you know, at some level though,
it is symbolic and it's kind of nice to think that,
you know, your mom is always carrying a bit of
you around, and you're always carrying around some of your mom.
But then but but again, it's just it's selves, it's
not it sells. But here's this just a complicated Like
there's a little her in your flesh pocket on your side,
and she's looking up at you like telling you to
(14:45):
eat your piece. Totally is right now my flesh pocket. Thanks, Yeah,
hey mom um. So here's here's something to complicated. There's
a possibility that sells from an older sibling residing in
the mother may find their way back across the placenta
to a younger sibling. Now that's where it just gets
(15:06):
kind of gross. Like, here's the weird thing, Like, it's
very possible that that I have not only my mom
cells floating around, but my brothers and my daughters. Which
is fine, I mean, obviously it's all working out. But
with your daughter, I mean obviously there's a stronger connective.
But you're you've discussed before how you and your brother
are kind of different organisms, right, I mean you're rather different. Well, yeah,
(15:29):
of course we're different in many ways. But it is
kind of interesting to me as at the second born.
It's always like, man, seriously, you always get like, you know,
second banana hand me down cells, right, thanks a lot.
Uh No, twins, of course, identical twins can also exchange
micro comeric cells through the sheriff of sentence, so us
(15:50):
I don't think anything that's shocking, especially since we've already
stablished they can merge together into one organism. Yeah, you know,
I don't put anything past them, exactly. You gotta watch
out for the twins. They'll do it before you're born.
If there are any twins out there listening, don't do
it later. So much hard to absorb each other or
across cells. Absorb each other or across cells. I mean,
both are a little more difficult and a little more
(16:10):
problematic if you do it as adults. It's true outside
the womb, that is, there's a menial logistics there. Um.
So here's some also interesting thing. There's evidence for competition
between cells from from grandmother in infant within the mother. Yeah.
So that's where it gets a little dicey, and that's
when we start to talk about autoimmune issues. Yeah, because
we have. One of the problems with the autoimmune situation
(16:32):
is that there's the theory is that you have essentially
alien cells in the body. In the immune system detects
alien cells, they're going to fight against them in the
same way that they would have destroyed a number of
them immediately following the birth of the child. So you
get that, you know, the problem of an autoimmune defense
network attacking the body itself and all the complications that
(16:55):
arise from that. Yeah, I mean because some autommune diseases,
which current women three times more than in men, are
thought to be associated with this problem, right, this sort
of they're not assimilating, right, um, the Civil War in
the Yeah, they're trying to figure out like why are
you here? Should you be here? Um? And that's when
you see sort of things like multiple multiple sclorious as
(17:15):
being exacerbated by this issue of fetal cells. Now, the
good news is that, um, these fetal cells can kind
of act like stem cells depending on where they are, Uh,
they can actually help to repair damage tissue. And they're
essentially a transplant of younger, healthier cells in depleted organs,
(17:37):
So they might help protect against certain types of cancer.
So women with breast cancer, for instance, they generally have
lower levels of microclimerrism than women who don't develop disease,
and the suggests a possible role for fetal cells and
helping to detect and destroy tumors because if you think
about it, uh, those microclimeric cells from a pregnancy, they're
(17:58):
recognized by the mom's immune system is belonging to the
mother since they're genetically half identical to the mother, so
they get a pass. So they're they're sort of foreign
to the immune system, but you know, because of the
father's contribution. But they also this is the idea, they
may prime the immune system to be alert for cells
(18:19):
that are similar to the self but with genetic differences.
So the idea is that having the presence of microchlimeric
cells and the body could kind of ferret out cancer
cells and then stem the growth of any tumors. Sort
of like, hey, we're on the alert for you, but
we're also and you're fine, you get a pass, but
these other guys they're not passing the test. So sometimes
(18:43):
hand me down. That stuff is really good stuff. That's
the thing. Sometimes you can really make something out of it. Yeah,
I mean, it's really cool and Nancy shoot, you had
mentioned before in her Beyond Birth article says that fetal
cells also appeared to migrate to injury sites and have
been found in patients with thyroid and liver damage where
they had morphed into organ cells. Wow, so like you can, Yeah,
(19:03):
you can, on a very soular level, you can get
into this idea that my daughter is healing me, my
my my son is healing my body well. And it's
interesting that you say that because there was one account
I can't remember which article, but one of them had
said that there was someone who was going through cancer
treatments and they kept that in mind. My son is
helping to heal me through this. His cells are combating
(19:25):
the cancer cells. And yes, there's a bit of magical
thinking to that, but it's sort of lovely. Yeah, just
don't let it fill into like full on cannibalism, because
I'd be like, I'm feeling at they're on a little
thick here. But I bet if I ate the kid's arm,
then I maybe get a replenishment. It won't work. Messy defects. Okay. Yeah, Um,
(19:48):
so of course we have to to start thinking about
this in a future sense and One of the ways
that researchers and scientists are is to actually look at dogs,
because it turns out microchimerism is present in some dogs,
and now makes setting the condition a lot easier because
you're talking about lifespans ten to twenty years as opposed
to seventy eighty years. So they begin to kind of
(20:10):
look at what that might mean, um, to have these
cells acting like stem cells, or even acting against the museum,
acting against museums, acting about against the immune system, and
then how does this affect the world of human cloning. Well,
it's not as straightforward as we thought, right, yeah, because
it's it's one thing. Because again, we we have this
(20:31):
this notion that we get in our heads that that
I am this one product and if you distole me
down on these cells, on this DNA, on this person,
and then if we can just recreate that data, then
we can recreate, at least in a bodily sense, we
can recreate ourselves. But now you're having to take into account.
I mean, we've discussed, um, you know, all the microbes
(20:51):
that live inside us, and now we have to take
into account different cellular communities from other individuals that make
up who we are, how do you replicate that in
a awning scenario? Right, and not to mention the microbiota
that exists within everyone that is also again influencing how
we moved through the world and what sort of diseases
we may or may not get. Also have the genetics, right, Yeah, Well,
(21:15):
it's like with with cloning. It's um it reminds me
of the movie The Boys from Brazil based on the book,
where you had a plot to clone Hitler and it's
the plot really has a has some fun with the
idea of well, you would have to not only have
a genetic duplicate, you would have to then recreate all
the circumstances that made that person who they were. And
(21:36):
uh in the film sort of operates on the idea that, well,
the genetic side is simple to genetic side is just
pretty straightforward. But it's that conditioning that's where the problem lies.
But we're saying more and more that the genetic side
of things, the cellular side of things is almost equally
complicated if you were actually trying to replicate an individual. Right,
So this idea that we're just unique and we're just
(21:58):
sort of preset with this program at birth, it's following
away away, because now we all realize that we really
truly are chimeras. Yeah, an innocence kind of ephemeral, I mean,
rather ephemeral. Yeah, all right, I just checked my pocket
of flesh and mom says it's time to wrap it up. Okay,
all right, well, uh well pocket of flesh mom, or
we will call it an episode then. But we'd love
(22:21):
to hear from all of you guys and gals out there.
What do you think about this information? Um? How does
it make you think about your relationships with with your parents,
with your children, with strangers, you know, sibling, your sibling,
you know? How does it make you feel that your older,
younger brother maybe a part of who you are on
a solar level? Does that creep you out? Or does
(22:42):
it give you hope? I don't know? And then how
do you and then you know, to what extent do
you draw thin magical interpretations of this into your indual world?
Few we'd love to hear from you. You You can find
us in all the normal places Stuff to blow your
mind dot com. That's the mothership, that's where we put
all of our stuff. You can also find us on
Facebook and find us on tumbler we're stuff be blow
be Mind, and both of those. We are blow the
(23:03):
Mind on Twitter and on YouTube we are Mind Stuff
Show and you can always drop us a line at
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