what is developmental biology why we need to understand ......development –>> underlying mechanism...
TRANSCRIPT
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introduction of developmental biology
• What is developmental biology
• Why we need to understand the mechanism of animal development
• Why developmental biology is so interesting
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Developmental of frog
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Development of sea urchin
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Development of chick
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Structure = function
• Aim of Developmental Biology is to find how animal structures are formed
• So, we need to know how the structure and the function is related.
• Examples
– Ossicles(耳小骨)
– Inner ear(内耳)
– others
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Knowing the mechanism of plant structures,,,
• Simple rule
– bifurcation
Parameters: length of each part, angle of bifurcation, frequency of bifurcation
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Tree generator
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Plants in the CG movies
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Knowing the mechanism of skin pattern formation,,,
C:/Users/skondo/Desktop/movie/その他のmovie/発生の動画/Zebrafish egg development over 24 hours.flvC:/Users/skondo/Desktop/movie/その他のmovie/発生の動画/Zebrafish egg development over 24 hours.flv
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Is the principle of the development very complex ?
• It could be. But cells can do it.
• >>it may be simple.
• In case of sea shells,,,,,
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Shells grow only at the edge
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Shells grow only at the edge
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How to make coiling sea shells
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How to make the Bivalvia
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Shells grow only at the edge
By changing the shape of this growing ring >>> many different sea shells are made.
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Developmental biology
Fertilized egg (mouse)Correctly arranged in space(by Hamada)
Differentiation( by Oda)
Morphogenesis(by Kondo)
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Two questions
• 1) explain how the Kon-Pei-Tou is made
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作業工程
• Keep rolling the heated giant pan• Spread the water containing high concentration of
sugar• Keep above operations for three days
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何が起きる?
転がる
砂糖のつぶ(半分液状)
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何が起きる?
転がる
砂糖のつぶ(半分液状)
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どこにくっつく??
砂糖のつぶ(半分液状)
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どこにくっつく??
Swelling part swells more
A hollow(dent) does not swell because it does not touch the pan
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Growth of coral
Corals eat planktons
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Two questions
• 2) explain how the shell of a turtle grows
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problem
• Shell can not be added from outside because no living cells is there.
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shell
Cells making the shell
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Developmental biologyBiological process in which a fertilized cell forms a
complex structure of adult body
Inside of a sperm ? (1700~)
Simply expand ?
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Developmental biologyBiological process in which a fertilized cell forms a
complex structure of adult body
Dynamically changes the shape.From simple to complex.
What is the underlying mechanism? Why we need to know it ?
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Structure = Function
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Structure = Function
Dialyzer for kidney disease patients
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In order to take care or cure these tissues, we need to how it is made.
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Difference between man-made machines and animals
Need to be assembled by some other autonomous
autonomy
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Difference between man-made machines and animals
regeneration
Need to be taken care Regenerates autonomously
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Developmental biology
• What is developmental biology– >> to understand how the complex structure is made
• Why we need to study the mechanism of development– >> underlying mechanism is different from that of
artificial manufacturing– >> we need to know the mechanism to cure the
diseases– >>FUN!!
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Strange structures
Sea dragon thorny oyster basket star
Pikachu sea snailTreehopperSp. of land snail
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Megaloceros giganteus
Unicorn whale
Shapes of real animals are sometimes much odder than monsters in the film
Stalk-eyed flies
Sp. of Treehopper
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Rarely not in the shape of living things, , ,
Sp. of sponge Sp. of sea cucumber
Question What kind of mechanism can
generate all these structure ??
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How is the structure complex ?Tissue levelOrgan, whole body
gene networkCell-cell interactionPhysical stress
Ligand-receptorCell migrationPolarity
Cell level
Shigeru KondoToday
Hiroshi Hamada6/1
Tohru nakano6/1
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Origin of Shape
No structure uniformsymmetric
structuredifferenceasymmetric
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Principles to form structuresKey wards of development
1. Physical constraint
2. Pattern in the egg
3. Epithelization1. Basal-apical polarity
2. Folding of cell sheet
4. Planer cell polarity
5. Compartment1. Master controller gene
6. Wave (Turing wave, BZ wave)
7. Apposition growth1. Sea shell
2. DLA
8. Fractal
Earlymicro
Late macro
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Physical constraint
compaction
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Cadherin binds the cell membranes
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Compaction inducesCell polarity and Differentiation
Origin of embryo
Origin of placenta
Cell polarity
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Positional information in eggs
Bicoid gene
Difference is already set in an egg!!
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Positional information in eggs
High conc. >>Head
Middle conc.>>Thorax
Low conc.>>Abdomen
Key wordsSegmentation genesGradient modelMorphogen
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Cascade of gene induction make the pattern more complex
Gene networkSegmentation genes in drosophila
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From assembled cells to a bag of cell sheet
Sea urchin vertebrates
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Shapes are made by the folding of cell sheet
Apical contraction Change of cell shape induce the folding of cell sheet
filopodiaWhat is the source of force ?
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Shapes made by the folding of cell sheet
Nerve tube (vertebrates) Eye development
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Shapes made by the folding of cell sheet
Drosophila ventral furrow
Frog gastrulation
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Planar cell polarityCell sheet needs to the direction to grow
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PCP mutants
Drosophila wing Mouse hair Drosophila eyeMouse sound sensory hair
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How to decide the directionality
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How to decide the directionality
Black are accumulated here
Black-yellow binds with high affinity
Passively yellow accumulated
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How to decide the directionality
Black-yellow binds with high affinity
Blacks come to bind yellowPassively yellow accumulated
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How to decide the directionality
Black-yellow binds with high affinity
Blacks come to bind yellowPassively yellow accumulated
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Compartment
Large structures are built by assembling the parts.
Is the body of animal continuous?Or can be divided into parts?
Too large structure is difficult to built correctly.
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Expression of genes show discreet boundaries
Posterior half
Anterior half
Expression of engrailed gene
Cells exclude each other
Patterns are made during development
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Pattern identified by gene expression
Drosophila embryo
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Patterns in zebrafish brain
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Pattern identified by gene expression
The adult mouse cerebellum is subdivided into an
array of >100 reproducible stripes
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Gene expression in a compartment
Down stream genes Down stream genes
Master controller
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Master controller gene of eye formation =pax6
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Ectopic expression of pax6
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Ectopic leg formation by antenapedia gene
Ectopic head formation of hydraby wnt gene
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Mutations in flower
Sepal: 萼(がく)片 Petal:花弁 stamen: 雄蕊 carpel:心皮(めしべ)
Se pe pe se se ca se st st pe
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waves
• Turing equation
stable wave Travelling wave
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Example of Turing wave
Does Turing mechanism involve in other system?
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Cellular slime mold
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Cellular slime mold
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Cellular slime mold
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Cellular slime mold
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Cellular slime mold
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Cellular slime mold
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Cellular slime mold
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In all process of development the travelling wave exists
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Wave is made by the cAMP signal
Receive the
cAMP signal
Deliver cAMP
Cells move toward the direction
of cAMP signal coming
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Relay of cAMP signal
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Migration of cells induced by cAMP
cAMP release
migration
Freezing for a while
cAMP
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What does happen with wave and migration ?
Center of spiral
Center of spiral is stable !
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Falling down by gravityand move
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simulation
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Cells rolling in the slime
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Fractal structure< repeated simple deformation
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Tree generator
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Plants in the CG movies
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レポート課題
• 伸び縮するシートを使って、この形(ヨツコブツノゼミ)どうやって作るかを考える