Question

please help! I also took a closer picture of the images.. thank you!

(1) Explain why neural crest cells migrating in the path2 migrate into the anterior but not posterior somite. Use terms: ephrin, Eph. (Ept) (2) In the intact condition of mouse, the Notch signaling keeps the neural precursors in an immature c proliferation state to expand the number of neuronal cells in later. Explain what will happen if the constitutive active form of Notch (continuously active Notch) is over-expressed in the mouse neural plate, that is, will it increase or reduce the number of neural cells? Why will it be so? (5pt) dorsal root ganglion ectoderm cell noto- choed ectoderm aorta sympathetic adreno- fate of neural crest cells cells Anterior dorsal root ganglion neural tube ot pigment cell somite 籌璇 Anterior 蓦鬟 Posterior Posterior est cells

Answer 1

1) The Eph receptor tyrosine kinases and the ephrin ligands have been shown to be essential for the migration of neural cells. Studies in EpH and Ephrin in embrios, reveals that EphB3 is expressed ventraly and Ephrin-B1 is expresed in posterior half of somites, and ephrin-B2 is expressed in posterio somite. This position are relationchip to the neural migration.

2) Increase the number of neural cells, the intracellular domain of notch (NICD) is relatioship to this. the middle cerebral artery occlusion leads to increased NSC proliferation and differentiation into new neurons in the ipsilateral SVZ