Neural plate

Question 1

What does the inhibition of BMP cause?

Answer 1

Neural induction of the ectoderm

Question 2

What does the inhibition of DPP cause?

Answer 2

Neurogenic region forms

Question 3

What is neurulation?

Answer 3

Rolling up of the neural plate to form the neural tube

Question 4

Examples of BMP inhibitors

Answer 4

Chordin, Noggin, Follistatin

Question 5

On a molecular level what happens in the presence of BMP?

Answer 5

Epidermalizing T-factors generated

Activation of the pathway that converts epidermal cells into keratinocytes

Question 6

On a molecular level what happens in the absence of BMP?

Answer 6

Neuralizing T-factors generated
Activates the gene for Neurogenin
Neurogenin activated the gene NeuroD
NeuroD causes the differentiation of the e.cell into a neuron

Question 7

What are the stages of mesoderm induction and patterning

Answer 7

1. Low Nodal levels- ventral mesoderm
2. High Nodal levels- organiser
3. Organiser releases BMP antagonists causing neural induction. Also dorsalises mesoderm

Question 8

What happens during gastrulation (xenopus)?

Answer 8

Dorsal mesoderm involutes and undergoes convergent extension

Mesoderm also differentiates into the notochord

Question 9

What cell movements occur during gastrulation?

Answer 9

Invagination= sheet of cells bend inwards
Ingression= indiv cells leave a sheet and become freely migating mesenchymal cells
Involution= sheet rolls inwards
Epiboly= sheet of cells spreads by thinning
Intercalation= rows of cells move between one another
Convergent extension= rows of cells intercalate, this is highly directional