1. Ectoderm Fate Neural tube development Building the brain You can see a lot by looking! The eye Epidermis development

2. Brief overview on Ectoderm fate

3. Neural Tube Development Primary and Secondary Neurulation. Primary Neurulation is Anterior portion of NT development, whereas posterior is secondary neurulation

4. Primary Neurulation

5. Neural Tube closure Either single or multiple points of closure A-P neuropores Problems with closure – Spina bifida – Anencephaly – craniorachischisis

6. Control of neural tube closure Genetic factors: – Pax3, Sonic hedgehog, and openbrain Environmental factors: – Cholesterol and Folate

7. Secondary Neurulation Formation of Medullary cord

8. Brain Development: AV axis

9. Brain Development: DV axis

10. Vertebrate Eye

11. Eye Field formation Otx gene expression is high – BMP, wnt signaling low Pax6 master regulator

12. Too much of a good thing? Increase in Sonic hedgehog Widespread decrease in Pax6

13. Retina differentiation Most Ventral cells=Pax2; optic stalk Dorsal cells= BMPs, Rx1 Rx1 regulates Pax6 and Six3

14. 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

15. Lens/Cornea differentiation

16. Epidermis: The other Ectoderm descendent

17. Development of Hair