L17- organ develoment Flashcards

1
Q

describe a lung

A

highly branched epithelial strucuture

airways and vasculature need to devlop on a cpprdiated manner

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2
Q

where is the origin of cells that develop into lung

A

foregut endoderm

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3
Q

what tf code dictates lung cell fate in the foregut endoderm

A

Nkx2.2 in the ventral foregut

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4
Q

what other tf codes dictate organ cell fate of the cells of the foregut endoderm

A

hex/apx8/nkx2.1 = thyroid
hex/albumin - liver
pdx-1 = pancreas

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5
Q

where does the lung cells bud towards in the foregut endoderm

A

to the cardiac region

as releasing gf

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6
Q

when does the lung branch left and right

A

E9.5

right bigger

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7
Q

what occurs at the same time as the lung bud branches

A

the single foregut starts to branch into 2

forms the dorsal oesophagus and ventral trachea

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8
Q

what signals and tf are involved in the single foregut branching

A

Sox2 defines the dorsal oesoph
Nkx2.2 defines the ventral trachea
these are set up by wnt , ko wnt = no seperation of the foregut

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9
Q

how are all the strucutres of the lung made

A

through reiterative branchign

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10
Q

what are the phases of lung development and when do they occur

A

embryonic - 3-8 weeks (bronchi and bronchioles)
pseudoglandular - 5-17 weeks (+terminal bronchioles)
canalicular - 16-20 weeks (dev of respiratory
bronchioles/ b.vessel invasion starts)
saccular - 19-38 weeks , (alveolar ducts )
alveolar 23 weeks + (alveoli sacs)

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11
Q

What are the three models of branching

A

domain branching
planar bifurcation
ortholongal bifurcation

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12
Q

descirbe domain braching

A

orderly sprout of new buds at specific distance form the tip of the stalk and at position around the circumference

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13
Q

describe planar bifurcation

A

expand then bifurcate

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14
Q

describe ortholongal bifurcation

A

first bifurcate planr then twist 90 and bifurctate- rosette

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15
Q

in planar branching what signals control outgrowth

A

fgf10 in M singals through fgfr2 in epi

fgf10 also induce bmp4 which enh outgrowth

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16
Q

what the role of shh in outgrowth of lung branching bud

A

induced bby bmp4
inhibits fgf10 and bud induction
- stop excessive branch sideways

17
Q

in planar branching what signals control bud arrest

A

fgf10 induce shh and spry2 in tip of cell
shh inh fgf10
spry2 inh fgfr in tip cell

18
Q

in planar branching what signals control bud branching

A

bmp4 is upreg by fgf10
bmp4 inh tip cell prolif
more lateral cells bulge out and grow to new source of fgf10

19
Q

describe the structure of a kidney

A

two main parts collecting system and nephron

20
Q

what is the origin of the cells of the kidney

A

paraxial mesoderm induce kindey formation in intermediate mesoderm
- reciprocal signals

21
Q

what does the intermediate mesoderm split into

A

nephrongenic cord

nephric duct

22
Q

what happens to the nephric uct at E10.5

A

lumen all the way through

23
Q

what happens to the nephrongenic cordat E10.5

A

part develops into mesanephric mesenchyme

24
Q

what do the sigals released from the mesaphrenic mesenchyme induce

A

formation of the urethric bud

through MET the UB then develop into nephron epi

25
descirbe the reciprocal nature if renal tubule development
ub induce by mm bud induce survival and aggregation of M branching then regulated by factors from the mesenchyme
26
what signalling induces the bud
GDNF-ret | GDNF prod by m
27
how many generation of repeated branching do Uretric bud undergo to form the collecting ducts
10
28
What the role of fgf in UB branch
promote the GDNF -ret loop
29
what the role of wnt in UB branch
promotes GDNF production by mesenchyme of UB
30
what the role of BMP$ in regualting UB outgrowth
negative reg
31
where is GREM1 present in ub branching an the effect
at the tip cell inh bmp4 therfore no neg reg on outgrowth
32
what the role of SLIT1 and ROBO2 on UB branching
inh the epi bud
33
what is the rike of wnt in ub branching
promotes elongation over expansion
34
what are teh similarities in lung and kidney branching
signal factors and mechanisms (tips and stalks) reciprocal interactions between different tissues regional activation / repression of signalling pathways
35
what are the differences in lung and kidney branching
Some of thefactors involved are different | Tissues give rise to the final organ by very different mechanisms