All language subtitles for Cells are Us-Bertalanffy lecture for pupils.Alfonso Martinez Arias.2023.03.720p

and it's my very very special pleasure

to introduce our today speaker the

speaker of the anniversary event here

Alfonso Martinez Arias Alfonso is is an

old friend and colleague

a long-term friend and colleague sorry

a well-established friend and calling no

and he's been here 10 years ago

and he has opened the entire Series so

I'm super happy that he could be

convinced to come here again

and tell us his story 10 years later of

what you need to know about Alfonso is I

think he

he was a superstar in genetics in flies

but he had a question that went beyond

that

and then completely abandoned I don't

know whether completely but in in terms

of Publications almost completely

abandoned flies and moved to an entirely

new thing and he simply was interested

and and thrilled by the question

what does it take for a single cell I

don't want to give you a talk what it

does it take for a single cell to

develop rather than divide

and that's something that wasn't easily

addressable in flies but was addressable

in vertebrate systems and I'm pretty

sure we will hear more about the power

of cells

and I think for me he's he's really a

role model you should follow your ideas

and it should not just stick to

something where you've been successful

at

I think that is something for your life

do you think you need to know what you

have to do in your next step next 10

years 20 30 50 no way

you will find out every day in you

and that's the way

you will hopefully enjoy your life and

you will be successful and make

important discoveries at least for

yourself maybe for the world as we will

see here with Alfonso Alfonso thanks a

lot for being here again and we're

looking forward to your presentation

thank you

[Applause]

Deutsche

foreign

foreign

in this Herald's Ford and then weld in

the v11 representation

shaft this is

burden

foreign

East

in English

expressions

[Applause]

[Music]

[Applause]

so I'll try to speak slowly which as

your friend knows is very difficult for

me

so um I don't know whether you've ever

wondered how we are made how many of you

have ever wondered where do we come from

how we are made

foreign

you don't have to raise a hand if you've

never asked that question

and how many of you think just out of

curiosity because we live in a certain

time that we are made by our genes that

everything that we are is in our genes

how many of you believe that

fascinating so what else is there to do

what else is there to do other than

genes so this question have been asked

by many people over the years and you

can see that here where there have been

many answers over over the years about

this some people think religiously this

is a beautiful sculpture by by August

Rodan which is representing the creation

out of the hand of God there goes Edam

and Eve Leonardo tried to Leonardo da

Vinci try to find this out I don't know

why this is not working but oh no

sorry about this but Leonardo da Vinci

tried to try to

um represent them and try to figure out

what was inside the room but people

today is very normal for all of you to

to to know that we come from inside the

womb of our of our mother in in some

mysterious way and that mysterious way

was represented Us in this um in those

things on the on the on the left ideas

more clear ideas about how we were made

how we were functioned appeared in the

17th century because of this treaty that

was published in France in the in the

1800s called The Man machine the man

machine was an idea because at that time

the physicists had discovered the loss

of nature people were starting to

construct devices based on mechanics so

they started to see that perhaps human

beings organisms acted like machines and

and this is one inside there were a lot

of machines and they LED people to start

some clever people to start making up

copies of ourselves as if we are

machines and one of the most remarkable

ones if you ever go to Switzerland is

this Trio of people by a very famous

Swiss watchmaker corpia Jacques dross

who built these three which are still in

neutral exactly as you see them there

there is a scribe that is a draftman and

there is a harpsichordist the the

draftsman it's an amazing piece of work

because as as you as you can see here it

moves the eyes it writes it can write up

to 10 different texts it will erase the

text when it's wrong and and it's

probably the first programmable you can

see there in the back of thing I mean

trees are very good at making these

precisions instruments and this was a

very very remarkable object and that's

the way people people made this

similarity they thought that we were

made of of some natural copy of of metal

and wires and plates this really got to

to a very interesting this this notion

of the man as a machine got to a

fantastic view by this man who many of

you don't know called Fritz can he

worked in Berlin and over a number of

years he published his work The Mensch

else industrial palast I mean it's a

very fascinating set of drawings which

he put out in in the form of booklets

over a number of years and and

represented the the human being as he

says as an industrial Palace I I learned

that somebody had made a movie putting

putting right I mean putting into into

motion what Fritz can this and you can

see it here and I hope that it will work

foreign

we are breathing that that's the lungs

now we focus on the heart the Palm that

is pumping

I think this is my favorite beat what

happens if you are an industrial Palace

when you eat there is a bar of chocolate

there it goes

and your throat

I like this bit it goes into the the

stomach and you can see they're throwing

all the acids everything to dissolve the

food there is a man with a liver waiting

for everything to accumulate

and then when everything is ready he

will pull the lever and there it goes

into the intestine

and there the goodies are separated from

the crap

you see there the goodies are floating

about and they're going to be insane

somewhere else

and the rest is going to the waist

and then we can get back that's where

the liver the pancreas is taking all the

goodies and translating them into into

something interesting remarkable it's

fun

there is a wee-wee going out

after you've separated the wings

and you know the goodies go one way

remarkable

so in many ways this idea of the man as

a machine

is the is the the the progenitor the

precursor of all these Prosthetics that

we know about and and really a lot of

things some of those are wishful

thinking but but some are real and you

know that many valves of the heart and

many other pieces of our body are made

mechanically out of this notion that

human beings there is something mechanic

about about the way we work however if

we look if you look at your skin I mean

today we know that this is not the way

we're our components is not whether a

metal our components are are other

elements that that we can watch if we

get deep into our body in the 60s there

was this movie that called The Fantastic

Voyage which they made it it's an

American movie which they take people

and make them really really small and

they make this little vehicle and then

they inject them into the blood of the

organism and they start navigating over

over the in this machine and what they

see it's it's it sells I mean there goes

the people it's it's a very classic

movie that has been made and people

navigate through the blood system and

they get into dangers in the different

organs and and so what they see is cells

because indeed

if we look beyond the

the surface if we get a bit deeper that

that's there you have a situation of the

uh that's the yeah there is a delay

that's my problem with the with the I

can see now so there you have the layers

of the skin that's but I mean we go even

deeper and nicer we can see this Majesty

of the cells because that's what we are

made of and as I will show you in a

minute it is the cells that make us in a

very interesting manner you can see here

one of Johan's favorite organs which is

the variety of eyes I mean the

creativity of the Celsius and armors

because if we look beyond that initial

surface we will see cells everywhere

look at the variety of cells

and I'd like you to think I mean if you

hear about it you are hearing me because

again these cells arrange in this

fantastic and these beautiful Palisades

which are essential for your hearing and

and to distinguish all the sounds so

wherever you look it sells because cells

have a variety of shape a variety of

form a variety of creativity that if you

think about DNA and you've seen some of

the pictures these mornings that some of

you have put DNA is very boring it's

just the same thing it doesn't have this

this kind of creativity or ability and

it surprises me and this is a theme that

I'd like to share with you why we have

fallen into the Trap that we are are

represented in our genes in some form

when actually we are represented in our

cell

in your body

you have 440

000 trillion cells 40 000 trillion cells

that's what your body is and what is

remarkable is that those cells are

changing all the time

so for example those numbers that are

giving you there are absolutely true you

are making two million red blood cells

per second each of you is making your

bone marrow is making two million think

about it every second

I mean every time I see this number I

achieve it it's absolutely remarkable

and what is interesting is that Johan

knows that and I is forever but not the

rest of your body in fact everything in

your body except your heart maybe and

certainly your eyes is turning over all

the time

you know sometimes you know the your

skin you get a new skin every every

month so to speak you get a new

intestine every two or three every part

of your body is turning over

in fact you are not going to be the same

in 10 years time

one of the things that excites me is

that your skeleton will change every 10

years it will be completely renewed well

that's because you know when my clothes

don't feed me it's because my skeleton

changes nothing else changes in my body

so I think I think that you have to you

have to appreciate that that you are

changing you are a work in progress of

yourselves that throughout your body who

you are in terms physically changes and

I find that very remarkable a lot of

that work is due to the fact that in

every organ of your body there is a very

special population of cells which are

called stem cells whose job is to do

this renewal I mean we think because we

see ourselves we tend to think that we

are something static that we are

something but actually there is a lot

going on we're just fleeting structures

fitting creations of ourselves this is

why

I find very remarkable that that today

everybody is saying that you're gonna

find who you are when you're gonna leave

when you're gonna die what all in the

DNA I could spend and maybe we can talk

later many examples in which that is not

the case you cannot pin down much of

what we are into and the problem is and

that's for you to to solve in the next

few years that is the cell because it is

all there is in the DNA all that it's in

the DNA is instruction to to make Nano

machines proteins and the protein

complexes are Nano machines

and those are in an aggregate in this

sort of milieu of lipids and sugars and

they create cells and in the cells

everything once you get a cell the cell

controls everything so it's not that the

genes make the cells once you create a

cell a cell controls everything think of

your nervous system it's not your genes

that is letting you listen that is

letting you think it is the interactions

between those cells the genes are just

providing the tools

and indeed inside the cells

there is a lot of Nano machines and you

can see that in the next movie

besides I mean there are machines this

is this is a representation

but that's um

as Johan knows a few years ago I was

very interested and I'm still in noise

how can we listen to the noise of the

cells there you have

very remarkable and really all these we

have gleaned over the last 50 years and

everybody and many colleagues have

contributed we think this is not a bad

representation of what is going on in

the cell so not only your cells are

changing all the time but your cells are

a constant

sea of activity

and you know we are going now out of the

nucleus you will see some of our

favorite molecules and some of you have

seen them today there is the nucleus

that you can see mitochondria floating

there you see the Golgi apparatus and

many of you this morning in the

cytoskeleton is a remarkable thing which

shows this Fleet in nature of everything

in us because here you have there are

cables that are scaffolding this is what

is the tubulin we we saw and you know

there are those things they actually

move like that they actually move like

that okay this has been shown and this

has been seen they have legs some of

them they carry they carry cargos

remarkable

and all this has has been today you can

see these things at the single molecule

level is like that has been the great

revolution in biology the ability to to

see these things

and you know these micro cubicles that

some of you they are constantly making

and unmaking they are constantly so all

this stability that we see all these

being being there sitting that I see

there is a lot going on not only at the

level of yourselves turning over but at

the level of the molecules

I don't know where they made that noise

is the acting that some you know when

cells explore those things

there's machines we know that there is

so that's what the genes do the genes

code for the parts of these Nano

machines and when these machines

assembled they start doing things that

genes cannot dream of but that's a

muscle contraction when you're running

so this is this is I want you to get

this idea that that cells are hubs of

activity and that that that not only

sells a hubs of activity but but we are

also hubs of activity of ourselves this

idea now this structure these remarkable

structure that is the cell how did it

come about

there are two kinds of cells there oh no

now it starts well that's not what I

wanted

I should have done it before

the magic that I made made reference to

Magic happens all the time so there are

two kinds of cells there are two kinds

of cells that you probably have learned

in school there are the prokaryotes and

there are eukaryotes the prokaryotes are

they very simple they don't have a

nucleus they have some DNA wrapped in

the middle they are simple cells but

don't be fooled by simpleness because

they've been here way before we arrived

and they will be here long after we are

gone so that that's very important and

very humbling to to have and then there

is a eukaryotic cells which are very

complicated they have all the so

bacteria that don't have all those

complexities that that you that I've

shown you there so how these very

complex structure how did it come about

how did it come about

um there was a woman called Lynne

Margolis who many years ago when when

she was a young woman she had a great

idea she noticed something very strange

you all know about mitochondria

and she had the thought that

mitochondria looked very very much like

bacteria so he had the idea that perhaps

what happened in the course of evolution

is that the way a eukaryotic cell arose

is at a certain point that there were

many different kinds of bacteria

unicellular organisms they were eating

each other all the time and in one of

those eating situations some bacteria

that perform the same function as the

mitochondria were eaten by another type

of cell and they started to cooperate

they figured out things to cooperate and

that she thinks is the way that the that

the in this merger in this merger this

is the way the eukaryotic cell arose in

fact there must have been many of these

mergers because when the the bacteria

that were eaten by one of the cells were

able to fix oxygen and were able to that

that gave rise there is all these

bacteria which are called cyanobacteria

a cell that ate one of those became the

plants and cells that ate other other

bacteria that were better better doing

not not able to fix oxygen that they

were fixing other things they gave rise

to the animals so this single cell

complicated organisms they they sort of

come you can see here the branch that

goes to the goes to the to the to the

plants and these other plants goes to

animal-like structures which are called

protista these protists are very very

remarkable uh this this is a drawing

from a very famous German scientist very

great artist also called Ernst Heckle

who was very interested by this world

and look at this remarkably a lot of

those are single cell organists those

are single cell organisms look at the

Variety that there are and some of them

are absolutely very very beautiful this

is some staining with some antibodies to

reveal the internal structure that's

called a stentor it's a very interesting

and intelligent animals I have a good

friend in Harvard who is interested in

the behavior of this simple cell in fact

this is a very it has a very good story

this this has fascinated the the

scientists for a long time so this this

thing called the center sits on the

floor and it's waiting there and if you

go and put a little bit of Ink on it a

little bit of it it will move like this

to try to get away all those drops if

you start pouring more it gets very

agitated and it starts agitating even

more and if you put even more what it

will do it gets so agitated that it

lifts itself off the ground and moves

somewhere else away from the ink so that

says that he's thinking even a single

cell can do that okay so that's very

remarkable and it is here somewhere here

that the ancestors of the animals lie in

this world of the protista of the of the

Single Cell prokaryotes something very

mysterious and I was talking to Stefan

this morning about that something very

mysterious must have happened here and

this is this is one of the great

mysteries of Life how do you go from

from this there is actually a whole

group of of animals like here of organic

sorry I should say organisms which are

not animals but but they they behave in

funny way they are much more complex

than these but they are not animals yet

an animal is a multicellular organism

and something must have happened at some

point you can see here some these very

interesting organisms that are not

animals they try to form colonies they

try to interact with each other but they

don't form these structures these

compact structures that are that are

animals at some point about 600 million

years ago I know it's an amazing numbers

I'm throwing numbers of you you know 40

000 trillion cells 500 million years I

mean when a physicist tells you about

stars and how many stars are in the

universe you can laugh because there is

more cells in the world than there are

stars in the universe at this very

moment so that's something that that

should humble and the physicists are

very afraid of biology by the way

should take very good we are very

impressed by the physicists but they are

very afraid of biology this is something

for you to think about ask them to

explain life to you okay in case there

is any Ephesus in the audience

but but you can see this very

interesting animals which uh sorry

organisms

this organisms are at the interface

between the the protista this single

cell organisms and the and the animals

and the first animals that appear there

seems to be a gap here all of a sudden

you start seeing when you look at

fossils you start seeing disorganisms

you just as in the sponges esponjias are

the first animals and we know that they

are animals do you also get these

beautiful

um medallions this is Hydra that some of

you know and of course there is a lot of

work going on here in in Heidelberg on

Hydra and this is another another

they're absolutely beautiful these are

the first experiments I mean what we are

looking is the remnants of experiments

that nature has done

these are not quite like us but they

obviously occupied the Earth for a for a

very long time when mostly was uh

submerged in in water and then

500 million years ago something

remarkable happened

it's called the Cambrian explosions

because all of a sudden this was

discovered in in a little Shale in in

Canada called the Burgess Shale and all

of a sudden out of this what you see

before is this boring organ not a great

variety of them and all of a sudden

about 500 million years ago you get a

huge explosion a huge experiment in

animal form you get a lot of weird

things I mean this famous biologist

Stephen J Gould has written a book

called this wonderful life about about

this this explosion they found all these

fossils with animals that some of them

resemble some of what we are today I

mean they they have what they call we

call bilateral symmetry they had to hit

any tail there are others that are very

very weird but it's clearly nature

experimenting

nature is experimenting here with form

and of course

it's not DNA that is experimenting it is

the cells that are experimenting with

configurations with activities with

things that that will fool them and out

of these Cambrian explosion

we got something that starts looking we

get Evolution going big time and you can

see here I mean you know initially uh

that's a tree of what happens I mean

what we what we are today it's a

consequence of this all of a sudden it

accelerates that once you invent cells

one one you get eukaryotic cells they

start exploring a very wide space

they're still being creative this is

this is what I find and indeed you know

cells are incredibly creative I mean it

is all down to the cells and they create

the structures like this here I mean

some of you talked about plants this

morning I mean this is the eye of a

flight you can see here on the left this

is one of my favorite structures that

you can see here so but you can see

there is a paramecium on the this is a

unicellular organism and that's 200

microns 200 microns a fifth of a

millimeter that is a fly that is not a

fake there is a fly which is about 200

microns and it has a nervous system and

it has eyes and it has wings and the

length of that

you will not be surprised that this

nervous system has thrown out all the

nuclei

that little fly is called Tinker Bella

Nana from Tinkerbell in Peter Pan so

because it's really like Tinkerbell in

many many different ways but you also

get the the the the Beautiful the beauty

of the I mean it's just it's just the

creativity of of cells it excels

anything that an artist can do and those

patterns and those shapes and everything

so how does all these come about well

because we are one cell one cell becomes

two two becomes four and so on and then

we become many

what you see in this movie here is

actually a human fertilized egg

now in in vitro fertilization clinics

people are giving movies of the eggs

that have been successfully fertilized

and they like to think that this is the

child we can discuss that later but but

they give them the movies

yeah yeah I can see that so there you go

you know a cell becomes two to become

and in the process of seven days what

you're seeing there is the first week of

the life of someone that that that's

what it is foreign

that's the important thing first and

then when there are millions and in the

process of being Millions the cells

start becoming different from each other

and doing things this by the way is from

a very wonderful book that we've had at

home for many years called cell Saras

which is the title of the talk really

because in a way to me

as you can see here the development of

an organ is that's what we are talking

about you often said I mean a fly of

course come also from a single cell but

but it's a dictatorship the fly is a

dictatorship this is a democracy the way

a vertebrate vertebrate develops it's a

democracy and and and you know it's it's

about cells it's turning is in terms of

a mapping genes into cells it's about

cells mapping into space and time and

genes are just instructions to make the

component of the cells and you can see

the beauty of development in in these

movies that just took a couple of random

ones here you have a drosophila embryo

the ones at the top are are zebrafish

Johan never gives me a movie of medaka

so one day maybe he will and I can put

it in the in the gallery and there you

have a chicken making making the Soma

it's absolutely absolutely amazing

um the first thing that the embryo does

or or this cell when it amplifies itself

now you get a whole bowl of cells that

are all the same and then it's gonna go

through this process called gastrulation

which very famous biologies that that

unfortunately passed away two years ago

Lou is well predefined in that manner

the most important event in your life is

not birth or marriage or death but

gastrulation

you didn't know that but you know that

now

and why is that the case and why is that

the case

because that's the moment that that ball

of cells

that is the outcome of the fertilization

engages into a choreography a cell

origami game which transforms that into

an organ this is a very famous xenobus

movie I know there is a friend of mine

in the audience I will be very happy to

see to see this movie and there you have

you know you have a lot of cells that

are all the same and all of a sudden

this choreography starts and out of that

choreography you get something that

looks like an embryo you can see why I

say there is self origami or it is a

choreography in fact the cells are

moving in very defined ways it's a very

this is a drawings of a scientist on

that something that that you can see

there you know some cells are going

inside and you can see how from

posterior to anterior you get you get

the nervous system which is outside

inside there are the muscles now I'll

tell you how you are never going to

forget what gastrulation is which is a

sentence not mine but of that famous

scientist called Ray Keller castrolation

is the act whereby you separate the

from the brain

that's what it is and in fact that

little hole that little halter which now

you're never going to forget gas

relation is the most important moment in

your life and is the one whereby you

separate the from the brain

and as we all know many people don't

achieve that separation very well

so that's very good

so

sorry I don't know I don't know why do

you know any

anyway

um

not sorry

um so but the question here is um how do

we how do we so we've gone these bionics

you know it's very good but if the cells

are all this creativity can we actually

change this bionic into something that

we can make with cells can we start

working instead of with wire and and and

metal can we actually

um use it to to build the can we use

cells how can we do that I told you

before that there are these stem cells

that are in every in every organ of ours

but there is a very special kind of stem

cell that doesn't really exist we've

managed to to get it in a plate out of

very early embryos and it's called the

embryonic stem cell okay this is the

embryonic stem cell oh sorry and the

embryonic stem cell I hope

can stay there it passes by

um I'm gonna try to to freeze it here I

I think I'm sorry about that well these

embryonic stem cells we get them out of

embryos we can culture them in a dish

for a very very very long time and and

they keep this ability to generate the

organism while they are on the plate and

it's very remarkable how do we know that

because if we put it back in an embryo

they will generate a mouse

okay and this is very important now many

years ago a scientists in Cambridge

called in Oxford at the time called

young Garden did an experiment that led

to this other experiments many years

later which is that you can take any

cell of your body

and actually get it back to the first

cell that was in the embryo you can turn

back the clock of the cells and this was

exploited by this person's senior

jamanaka younger than work with frog

shinia jamanaka work with with human

cells and with and and and what he did

is this kind of reprogramming which as

you can see here you take cells from

skin cells and using a cocktail of

transcription factors of molecules you

can turn them back into embryonic stem

cells we then you can differentiate

that's what stem cells do into any cell

tissue of the organ and now the idea is

people are working on this very actively

now you should be able to take these

cells and use them as the source of

those tissues and repair and and that's

really what's being done these days in

in terms of the of the engineering I

mean a lot of work is being done these

days precisely about about turning these

cells into the into the

in the the the different parts of the

organs of the organisms we already know

for example these cells if you don't do

anything to them I don't know it is he's

taking there is very little we can do I

know but but if you turn them you can

turn them into brains for example you

can turn them into levers you can turn

them into ice it's it's a very um we

know we are not sure it's a bit of an

Alchemy it's something that happens and

indeed this reminds me that the lecture

that I gave 10 years ago sort of had

very big references to Harry Potter and

I looked at it and I say that I was

talking about the alchemy that that we

can do to get cells to do that so using

embryonic stem cells in the case of the

mouse we have been managed many together

with other people to reproduce the very

earliest stages of development and I put

Harry Potter there because there is a

lot of magic it is for you guys who are

interested in this to explain to us what

is that is going on after all let's not

look down into Alchemy because Alchemy

is is the progenitor is what gives rise

to chemistry so the Alchemy is not bad

it's just very early chemistry so using

this um

these kind of tricks with those stem

cells we've managed to reproduce the

very early stages of development but we

were wondering about whether we could

reproduce gastrulation which is that

moment in which we're going to change

the the the whole mass of cells into

something that that shapes us and and we

did that in the lab and you don't need

to worry about the details we we call

these things gastroits and you can see

we put a very small number of cells and

the cells seem to know how many they are

and if we put the right number of cells

and they all get together in the right

time you actually you start getting for

example you will see now a gene there

that is starting to be expressed and it

becomes restricted we start with about

two three hundred cells and as you can

see here those 300 cells become these

very um is very very remarkable objects

that elongate and and when we look at

the genes that they are expressing there

we see that they seem to have the same

organization in gene expression as an

embryo in fact as you can see here these

things are quite a coordinate system in

which in which you you have the three

coordinates you have the enteroposterior

the doors of ventral and the left right

this is in vitro this is in a dish so

these cells have an ability to to make

to make something that very much

resembles the organization of an embryo

you don't need to worry about these

pictures it's just to show you that the

organization of the cells in this

structures is very much that of the

embryo and that they follow Paths of

differentiation there is a very special

class of genes called the oxygens that

we all have which seem to act as a ruler

about what the different parts of the

body have to do from anterior to

posterior so they are very special genes

because they are very conserved they are

always expressing like a Russian doll

kind of pattern and indeed in these

structures that we call Gastrology they

have the same expression pattern you can

see that they have this nested

expression so these these structures are

very intriguing

and and we can we can follow in them

that that's the cells we can follow all

the different parts of the of the earth

we can make in every systems we can make

muscles we can make guts we can make

blood we can make a heart but you don't

need so but this is all integrated this

is this is really like an embryo but

some of you might have realized that

this is not this does not look like an

embryo although it has all the genes

perfectly organized it's lacking

something

and that's something probably is some

interactions between cells that are

going to shape that into something that

looks more like an embryo because an

embryo an organism is not just a

collection of genes it's also a

collection of cell interactions and in

this lab culture system you have you're

missing that that component of input it

is this is a very famous set of drawings

from Picasso what we are we're picking

up is the essence of the organism it

doesn't look like a bull but it has many

of the elements of a bull and and you

can recognize that as a structure of a

bull all this work was done with mice so

we wonder what would happen if we could

do it with with humans and and try to

see what what the anardo did and indeed

I mean we managed to create these

structures which We call gastruloids we

they they are this is from from human

cells and they look very much like the

same of the mouse they have this very

beautiful organization of gene

expression they are very reproducible

they have been very very efficiently and

all you need to know we we get them to

to do all sorts of things and we can do

all sorts of analysis that you don't

need to to worry about and when we look

because there are ways that we can say

how old what what stage of embryo

Genesis of the development of a human

being these structures re resemble and

we realize that we have managed to reach

about 21 days which is at the end of

gastrulation

so we are able to reproduce or well not

we use the cells we've managed to

communicate with the cells in a manner

that we've encouraged them to reproduce

the very early stages of human

development

this is very important why it's very

important because there is no way of

studying human development we can study

animals we can study mice we can study

fish but we cannot study humans because

we cannot do experiments with humans so

the fact that with cells we've managed

to create a system that reproduces many

of the earliest stages of human

development is going to allow us to

create and learn something about the the

how the basic body plan the basic

structure that we are coming to being

and for example we're producing this

system various special processes here

you have a very a very famous process

which is called sometogenesis is

basically we are segmented and we grow

from anterior to posterior and during

this time in the embryo you lay down

these masses of cells which are called

somites which will give rise to your

ribs to the muscles of your thorax and

we managed to reproduce this image you

can see there how this is one of these

gastroes and you can see how they are

they are doing that and what you can see

here in this movie

you can see that over time there is one

more segment attached there is one more

segment the way this is growing is

because these segments are going that's

associated with rhythmic gene expression

that we haven't seen in humans before

and I think it should work here there

you go and you can see as the thing

elongates you get this gene expression

being being pattern and we can reproduce

this in the in the in the dish

so I think that this is going to be very

useful to study and we are collaborating

with a group in in with a colleague to

try to use this to study the origin of

many spinal cord malformations and many

spinal cord things and there is other

people that are using this system to

generate hearts hearts are not just a

group of cells that come and give rise

to the heart it requires the integration

of many different cell types and cell

signals that that are that are very

difficult to generate simply by by

trying to steal everything to make a

harder hard is the cooperation of many

different cell types and and there are

these are called organoids but but they

come from embryonic cells and from

creating this little blueprint of the

organism that allows the cells to

interact and to and to generate the the

the heart

ten years ago I did give the I mean I

looked at this and and I was very funny

I think that's maybe Joachim will

remember that was the title of the

lecture genetic Alchemy and the making

of animal embryos and the last is light

of that lecture was this that cells are

the link between the molecules of the

organism they are the ultimate

Alchemists I think 10 years later we

have a lot more evidence that this is

absolutely the case and that indeed I

mean you know the the the the the

elements the cells are the ones that

integrate all these elements and make a

a

an organism

and I'd like to to finish coming to the

end with this I like always fantastic

quotation from Stephen J Gould which

which to me it says I think it's there

and it's Aus Reiner of Reagan Uber

Thrift the evolutions

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foreign

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and with that and reminding that it's

not just Alchemy I just want to thank

you for listening to me and I look

forward to talking with you later

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