Morphogens Flashcards
What are the types of signalling between cells
diffusible signals, membrane bound signals
Describe diffusible signals between cells
between membrane bound receptors or intracellular receptors
Give an example of membrane bound receptors used for signalling
growth factors
Give an example of intracellular receptors used for signaling
steroid hormones
Describe morphogens
Signalling molecules that can generate shape, and a concentration grad
How are morphogens produced
from a localised source
How are morphogens usually sensed?
through cell surface receptors
What does the french flag model show?
that cells respond differently to different levels of pigment
What type of development does the french flag model account for?
regulative development
How are morphogens transported?
simple diffusion, transcytosis, and by the extracellular matrix
Describe transcytosis
signalling molecules are taken up by vesicles
Give examples of signalling centres
zone of polarising activity in CLB, bicoid gradient,
Where is bicoid usually located?
localised to anterior end
What does bicoid code for
transcription factor
What does bicoid regulate
expression of hunchback
