Developmental Processes Flashcards
what is polarisation
form apical complex
driving force behind the first lineage restriction
what cells become polarised
TE cells become polarised, while ICM cells lack apical/basal polarity
what is asymmetric cell div
segregation of apical complex
what sit he cell position
suppression of apical complex in inner cells
what is cell fate
restricted expression of lineage sp genes
what are the signalling centres
organiser
dorsal blastopore lip on ventral side of unpigmented host embryo
new neural tube
second embryo form
what are signalling gradients
positional info
cells respond in sp way dept on conc of signal mol
what do signalling gradients regulate
differentiation in the neural tube by providing positional info
where is Shh prod
in notochord and floor plate
diffuses dorsally
where is high levels Shh found
cells near floor plate
when does Shh conc decrease
dorsally giving rise to diff cell types
what happens if more Shh is added dorsally
change in cell fate due to and increase conc Shh
what are dorsal cell after induced by
TGF(beta) signalling
opposes effects of Shh
what does programmed cll death do
help shape embryo
what does BMP4 signalling trigger
cell death programme in interdigital zones of foot and hand
what do localised changes in shape in neuralation lead to
folding of neural plate at median an dorso-lateral hinge points
where does tissue fusion occur
as edges of neural plate together
what is imp for formation of face
tissue folding
how many facial swellings
5
when is there cell migration
gastrulation
neural crest
germ cells
interneurons
what is epithelial cell state
cells in sheets with specialised mem contacts adherent and tight junctions
what is mesenchymal cell state
loosely assc often motile cells with only transient focal attachments to other cells
transition between epi cell state and mesenchymal cells state required for
gastrulation neural crest vertebrae cardiac valves secondary palate formation
essentially what is `EMT
tissue remodelling
what si the EMT pathwa
extra cell signals - signal mol and GF’s
transcription factors which repress key cell adhesion molecules
E- Cadherin caretaker of epi cell state
what are 90% oral cancers have EMT
squamous cell carcinomas often characterised by low E-Cadherin expression
