Eye development Flashcards
Where do the cells of the eye originally come from?
Epidermal ectoderm and diencephalon
What forms the optic vesicle?
Lateral expansion of the diencephalon
How does the optic vesicle become the optic cup?
It signals the epidermis above it to induce it to become the lens placode. The lens placode will send a reciprocal signal back to the optic vesicle, which produces the optic cup
What does the optic cup do to form an eye?
It bends and pulls the lens vesicle inside, and the epidermis grows back over top of it. Then the optic cup differentiates into the retina
What is the eye field?
The early signals in the germ layer that place the eye where its supposed to be
What signal places the eye field?
Noggin
What does Noggin do to place the eye field?
Inhibits ET and promotes activity of Otx2
What does Otx2 do?
Is a transcription factor that allows ET to be expressed in the optic vesicle
What does ET do in the optic vesicle?
Activates Rx1
What does Rx1 do?
A transcription factor that activates Pax6 and Six3
What do Pax6 and Six3 do?
Causes retinal cell differentiation. Pax6 specifies retinal ganglion cells and Six3 regulates cell division
What happens to the eye field if there is an overexpression of ET?
It becomes enlarged
What is the prechordal plate?
The most anterior part of the notochord
What does the prechordal plate do?
Secretes Shh to cause the eye field to separate into bilateral fields
What happens to the eyes if Shh is blocked?
Cyclopia
