L16 tooth development Flashcards
where do enamel cell originate
ectodermal ridge
where do dentine cell origniate
ncc
why tooth development good eg to study
reciprocal interaction m and e (2 germ layer orgin)
bmp4 signal ised various stages
can study without lethal effect
what is the process of tooth morphogenesis
thickening of placode = E11.5
bud - with the M condesing around epi = E13.5
cap - extends further = E14.5
bell - condensing M has enclosed epi and the
differentiation of denitne vs enamel occurs =E18.5
where is the odontogenic potenital before day 12
in epi
epi says m make tooth
where is the odontogenic potential after day 12
in mesenchyme
m returns signal says epi make tooth
how does th eodontogenic potential differ to hari follilcle initiation
in hf is m then epi
what is the marker for tooth location
pax9
how is pax 9 set up
epi and m interaction
remove ecto b4 d 11 no pax9
only when replace with cranium ecto can save
what signals dictate spatial location of pax9
fgf act
bmp inh
what is fgf8 in positive feedback iwht in the epi
pitx2
role of dynamic bmp4
moves with time
allows second wave of pax9 induction
what other tf does fgf8 act in the oral mesenchyme
lhx6/7
nec not sufficient
role in tooth location
what is thr ole ofm gsc tf in the tooth location
expr after lhx6/7
pos reg with fgf8
but exclude from lhx6/7 domain
gives the no form tooth identitiy
what tf can be viewed jaw didivided into to give tooth location
pax9 = tooth gsc = no tooth
what do cross species epi and m combinations show about teeth in birds
oral m does not produce a signal
oral epi does
can induce mineralised strucutre in hen
what signals norm expr in hen mouth different from mammal
bm4 not expr
fgf8 is
what suggests a role for wnt in tooth dev
as if act b cat in chick induce tooth dev
what are the two tf for tooth identity
msx1
barx1
both expr in dental mesenchyme
what tooth fate do msx1
barx1 give
incisor (proximal)
molar (distal)
what is signals controlm the expression of barx1
fgf8 induce
bmp4 inh
what the ptype if ko bmp4
incisor to molar
what are enamle knots
singalling centres of teeth
important for molar morphogenesis
do not prolif
what are the first singal rel by enamel knots that drive prolif
BMP and FGF
role of fgf4 in molar morphogensis
involution of dental epi
form cusps
role of shh and wnt in epi
set up boundary oral and dental
wnt7b in non dental inh shh
shh induce by bmp4
what does a mut in the EDAR pathway result in
ectodermal dysplasia
abn dev of ectodermal appendages
save if give pregnant mouse recombinant form of eda pr
edar mut in tooth dev ptype
no edar
no enamel knot
no cusps
what are ameloblasts
the cell types in tooth that produce enamel
derived from ecto
what are odontoblasts
cells in tooth that prodcue dentine
derive from ncc and m
what the ptype of ameloblast enamel in bmp4 ko/overexor
ko = no enamle
overexpr- ectopic ameloblasts
what the role of runx2 in tooth
in the m
controlm odontoblast and ameloblast no
what is the role of fgf4/8 in stem cell niche of incisor
promote proliferation and survival
