Morphogenesis Flashcards
What is morphogenesis stimulated by?
Chemical factors-contc. extracellular matrix and mechanical factors- contact with other cells
What are the extra cellular, environmental cues that guide migrant cells?
Specific cell-surface receptor proteins (repelling or inviting)
What are some intracellular cues?
inside the proteins are connected to actin and myosin cytoskeleton moving the cell along
What are two important examples of guiding influence?
neurons in developing brain and cancer sells when they metastasize
What is CXCR4?
A G-protein coupled receptor that influences chemotaxis and is dependent on an extracellular ligant
What is CXCL12
Extracellular ligant that induces directional cell migration
What happens with no CXCL?
Random blebbing
What are the most important migrant cells
Those from neural crest
What forms the neural tube?
Neural ectoderm
What is the survival factor that is involved with neural crest cell migration?
Endothelin-3
How can you detect Endothelin-3 mutation?
Undeveloped colon
What is Kit?
Receptor tyrosine kinase, survival factor
Where is Endothelin-3 produces?
in tissues along migration pathway
Where is Kit produced?
Cell surface of migrant cells
What is the ligant for Kit?
Steel factor
What happens with mutation in Kit?
Defect pigmentation
What are cadherins?
cell-adhesion molecules, ca dependent
What do different types of cadherins lead to?
Sorting out cells
Apart from cell adhesion what is important in cell separation?
Active cell repelling
What is convergent extension?
Active rearrangement by migrating cells
What is planer polarity?
All cells pointing in a specific direction
give an example of planer polarity defect
mutation in Flamingo gene that makes mice deaf because of different direction of hairs in inner ear
From where did lung tissue originate?
Epithelial buds, foregut
What needs to happen for formation of bronchial tree?
Invasion of mesenchyme
What else apart from epithelial cells invade the mesenchyme?
endothelial cells from blood vessels
What does branching morphogenesis depend on?
FGF and their receptor kinase
How does FGF-10 work?
FGF-10 expressed n clusters of mesenchyme and the receptors on epithelial cells that way epithelial cells will grow towards mesenchymal
What signal does the epithelial cell send to mesenchymal cells?
Sonic hedgehog (shh)
What is then function of shh?
Inhibition of FGF10
Give another example of morphogenesis directed by FGF10
Filopodia of tracheal tube in Drosophila
What induces FGF expression in early development of flies?
D-V and A-P patterning systems
What induces FGF expression in early development of flies?
hypoxia-inducible factors (HIF)
How are epithelial sheets converted in tubes?
Specific actin filament contractions connected by adherans junctions along an axis
What is the name describing a fetal thymus that transplanted grows to its specific size?
Local intrinsic feedback
Why is C elegans perfect to study growth?
Each individual generates same sequences of cell division and
cell death, ending up with same number of somatic cells
How come that C elegans has all the cells after 3 days but didnt reach maturity yet?
Continues growth through endoreplication of genome, polyploidy
