Cell to Cell Communication in Development & Principles of Experimental Embryology Flashcards
organs are formed by interactions between
cells & tissues
define inducer
cells/tissues that produce a chemical signal which results in a change in another cell’s fate
what is the name for the process where a cell’s fate is changed?
induction
define responder
cells or tissues which receive the inducing signal
define competence
the ability of cells/ tissues to respond to inducing factors
competence is typically governed by _________. Give an example
chemical mediators
Ex: proteins
define reciprocity
a cyclical pattern of induction between a community of cells
give an example of an inductive interaction
the epithelial-mesenchymal interactions
list the 3 types of inductive interactions
- paracrine factors
- juxtacrine factors
- autocrine factors
describe paracrine factors
the diffusion of proteins over a short distance
describe juxtacrine factors
physical interactions between surface protein w/ cell receptor
describe autocrine factors
cells respond to their own paracrine factors
which factor travels greater distances: inducing or endocrine
endocrine
describe the notch pathway
the physical interaction between adjacent cells for the induction process
the notch pathway is an example of which type of signaling
juxtacrine signaling
explain the mechanism of the notch pathway
a portion of the responder is cleaved by protease enzymes to activate target genes
activation of what causes DNA to be exposed
histone acetyltransferases
what type of signaling is commonly found in the nervous sytem?
juxtacrine signaling
signal transduction is a a cascade of biochemical events that lead to
gene expression
in signal transduction what happens to the receptor
ligand binding causes a conformational change
signal transduction activates enzyme activity beginning w/ the
G-protein
what is key in signal transduction
phosphorylation
what are the 2 types of interactions between inducers and responders
- instructive interaction
- permissive interaction
describe instructive interactions
inducing tissue gives instruction for responding cells to commit to a specific pathway of development
give an example of an instructive interaction
mesenchyme and epithelial ectoderm leading to differentiation
describe permissive interaction
responder is already specified but needs the proper environment to develop
the RAS-G protein is a component of which signal transduction pathway
paracrine
the RAS-G protein is used by growth factors to
initiate cell growth and differentiation
mutation in RAS pathway leads to
human tumors
the JAK-STAT pathway is responsible for the…
differentiation of formed elements in blood and limb formation
mutations in the JAK-STAT pathway leads to
- dwarfism
- deficiency in specific blood types