Dry Lab 3

Question 1

What is Dpp?

Answer 1

• a long-range morphogen
• a bone morphogenetic protein (BMP)
• controls patterning and growth of the wing

Question 2

Where is Dpp located?

Answer 2

• secreted from a stripe of cells at the anterior-posterior compartment boundary
• spreads into both compartments

Question 3

What is Pent?

Answer 3

• a transcriptional target of BMP signalling that encodes a secreted regulator

Question 4

Where is Pent expressed?

Answer 4

• high in lateral and absent in medial

Question 5

What happens when pent is absent?

Answer 5

• there is a severe contraction of the BMP activity gradient causing patterning and growth defects
• truncation of longitudinal vein
• smaller wings in lateral region due to less cells
• BMP activity elevated in medial regions and smooth pMAD gradient failed to establish

Question 6

What does pent interact with?

Answer 6

• glypcian Dally to control Dpp distribution

- BMP confines pent expression to lateral cells of the wing disc

Question 7

What are silencer elements?

Answer 7

• small DNA motif embedded in the regulatory region of target genes
• Mad and Medea bind to SEs of …

Question 8

What happens if BMP is eliminated? Over-expressed?

Answer 8

• elimination of BMP causes upregulation of pent expression

- ectopic activation of BMP causes downregulation of lateral pent expression

Question 9

What is an example of a long-term morphogen?

Answer 9

• Dpp
• pent encodes a secreted protein that functions over long distances in the wing disc epithelium
• V5-pent