Ectoderm Fate Neural tube development Building the brain You can see a lot by looking! The eye...
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Transcript of Ectoderm Fate Neural tube development Building the brain You can see a lot by looking! The eye...
Ectoderm Fate
• Neural tube development• Building the brain• You can see a lot by looking! The eye• Epidermis development
Brief overview on Ectoderm fate
Neural Tube Development
• Primary and Secondary Neurulation.
• Primary Neurulation is Anterior portion of NT development, whereas posterior is secondary neurulation
Primary Neurulation
Neural Tube closure• Either single or multiple points of closure• A-P neuropores• Problems with closure
– Spina bifida– Anencephaly– craniorachischisis
Control of neural tube closure• Genetic factors:
– Pax3, Sonic hedgehog, and openbrain
• Environmental factors:– Cholesterol and Folate
Secondary Neurulation• Formation of Medullary cord
Brain Development: AV axis
Brain Development: DV axis
Vertebrate Eye
Eye Field formation• Otx gene expression is high
– BMP, wnt signaling low
• Pax6 master regulator
Too much of a good thing?
• Increase in Sonic hedgehog• Widespread decrease in Pax6
Retina differentiation• Most Ventral cells=Pax2; optic stalk• Dorsal cells= BMPs, Rx1• Rx1 regulates Pax6 and Six3
Retina differentiation• Fate of neuroblast
determined by translation, not transcription
• Photoacceptor genes regulated by Xotx5b
• Xotx2 and Xvsx1 specify bipolar neurons.
• All transcribed in retinal cells• Translation regulated by
miRNAs– miR129– miR155– miR214– miR222
Lens/Cornea differentiation
Epidermis: The other Ectoderm descendent
Development of Hair
Development of Hair
Development of Hair