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Flashcards in Cell determination Deck (13)
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What results from cells with activated proneural genes

Become neuroblasts - Competent to become neurons


What is seen in proneural mutants

No cells become neurons


What happens in a Notch mutant

More neurons are formed


What is lateral inhibition

Involves transmission of an inhibitory signal between a pair or cluster of cells to prevent the cells receiving that signal from becoming a particular fate


How does the Delta Notch signalling pathway occur

Upregulation of Notch signalling occurs in one cell
This causes upregulation of the transcription factor - suppressor of hairless
This causes the upregulation of the transcription factor enhancer of split
This acts on the promoter or Achaete-scute to downregulate its production
This reduces delta production in that cell
Opposite effect is seen in the adjacent cell (les notch signalling -> increased delta)


How do cells acquire neuronal cell fates via delta notch signalling

Achaete-scute needed in particularly high levels to turn on activation of other TF's which promote neuronal identity


What dictates neural diffusion

Transcription factor code - as cells differentiate they move laterally


Where do some daughter cells migrate to if they differentiate into mature neurons

The mantle zone


Where do daughter cells of progenitors that don't differentiate stay

Stay in the ventricular zone - luminal surface of the neural tube epithelium - remain as a progenitor cell


What is the shape of the progenitor cells that dont differentiate

Radial glia - provide a pool of undifferentiated cells that are used to build up the nervous system over time in embryogenesis


Where are radial glia located

Big cell body in the ventricular zone and send long processes to the pial surface - outer mantle


How do radial glia divide

Asymmetrically - one remains as a radial glia - the other uses the scaffold provided by its sister to migrate away from the ventricular zone and will differentiate into a neuron


What is the importance of the asymmetrical division of neural progenitors

It occurs throughout the brain and spinal cord - converting one cell thick neural tube into the multiple layered cortices of the spinal cord and cerebrum/cerebellum