Lecture 5 - Production of different embryo cells in proportion to one another

Question 1

What are spaced patterns within an embryo?

Answer 1

A pattern between two tissue types

Question 2

Give an example of spaced patterns.

Answer 2

• Chicks

- Need a proportion of feather and skin cells

Question 3

How are the spaced patterns produced?

Answer 3

Via lateral inhibition signals

- Centre cell emits a signal that inhibits surround cells from becoming the same cell type at the centre cell

Question 4

True or False? Every cell has the potential to become the centre cell.

Answer 4

True

Question 5

What phenotype does the Drosophila Proneural mutant have?

Answer 5

Failed to make sensory bristles

Question 6

What phenotype does the Drosophila Neurogenic mutant have?

Answer 6

Makes too many sensory bristles

Question 7

What causes Neurogenic mutants?

Answer 7

A failure of lateral inhibition

Question 8

What are Mosaics?

Answer 8

small groups of cells that are mutants, within wildtype background

Question 9

Which cell needs to have the receptor?

Answer 9

The receiving cell

Question 10

What can genetic mosaics be used to distinguish?

Answer 10

Between signal and receptor proteins

Question 11

Is Notch the receptor or the signal?

Answer 11

Receptor

Question 12

Is Delta the receptor or the signal?

Answer 12

Signal

Question 13

What happens to a Notch mutant clone?

Answer 13

• There isn’t enough lateral inhibition

- Too many sensory bristles are made

Question 14

What are proneural genes responsible for?

Answer 14

Initiatating peripheral

nervous system development

Question 15

What happens to Proneural mutants?

Answer 15

A mutant fails to make Proneural cluster all together

Question 16

What happens as a leaf gets bigger?

Answer 16

• Trichomes are added

- Space is left between them for photosynthetic cells

Question 17

What are the two forms Trichome mutants can take? [2]

Answer 17

• Not enough trichomes

- Too many trichomes

Question 18

How is trichome development promoted?

Answer 18

Gl1, TTG1, GI3 form a transcriptional complex

Question 19

What is the relationship betwwen Try/Cpc and GI1?

Answer 19

• Try/Cpc is activated by Gl1

- Cells that express Gl1 also express Try/Cpc