14. Neural Crest Cell Development Flashcards
(20 cards)
What are morphogens?
Secreted molecules that diffuse to create gradients
Morphogens influence target cells based on their position and receptor expression.
What is the significance of morphogen gradients in development?
Key to spatiotemporal control of development
Different cellular responses are elicited based on the amount of morphogen received.
Name three morphogens involved in neural tube development.
- Sonic Hedgehog
- BMP
- Noggin
Where do neural crest cells form?
At the interface between surface ectoderm and neural tube
This is where they undergo significant transitions.
What is epithelial-to-mesenchymal transition (EMT)?
A process where cells lose adhesion molecules, acquire a mesenchymal phenotype, detach, and become migratory
EMT is crucial for neural crest cell development.
List some cell types that neural crest cells can give rise to.
- Neuronal derivatives
- Glial cells
- Bone and cartilage
- Other tissues
What determines the fate of neural crest cells?
Their migratory journey and signals from the environment
This highlights the importance of external factors in development.
What are cranial neural crest cells known for?
Most potent and give rise to facial cartilage and bone, and cranial nerves
They migrate through the face and pharyngeal arches.
What do vagal neural crest cells contribute to?
Enteric nervous system in the gut
They are located in somites 1-7.
What is a key function of cardiac neural crest cells?
Form septum separating aorta and pulmonary artery
Defects in this population can lead to congenital heart disorders.
What do trunk neural crest cells form?
Adrenal medulla, which produces adrenaline and noradrenaline
Their potential is more restricted compared to cranial neural crest.
What are the two main migration pathways of neural crest cells?
- Dorsolateral pathway
- Ventral pathway
What induces epithelial-to-mesenchymal transition in neural crest cells?
BMP and Wnt signaling induce Snail2
Snail2 is a master regulator of EMT.
What is contact inhibition of locomotion?
Cells repolarize and move away from each other upon contact
Mediated by PCP proteins.
Describe collective migration in neural crest cells.
Leader cells establish polarity, while follower cells maintain contact with leaders
Involves asymmetric localization of Rac1 and RhoA.
What role do environmental factors play in neural crest cell migration?
Guide migration through attractants and repellents
This includes signaling molecules that influence direction.
Provide an example of a guidance cue in cranial neural crest migration.
SDF1 (CXCL12) acts as an attractant
Neural crest cells express the CXCR4 receptor to respond to this cue.
What does ‘chase and run’ refer to in neural crest cell migration?
Neural crest cells chase placode cells, causing physical contact that prompts movement
This process continues until they reach their destination.
What is a common theme of morphogen gradients in development?
They create guidance cues for cell migration
This mechanism is conserved across different biological systems.
What are the consequences of defects in neural crest development?
Lead to various disorders
Proper development is crucial for multiple structures in the body.
