Lecture 12 - Segment identify: Hox genes

Question 1

What do all bilaterian animals have in common with their DNA?

Answer 1

They all have Hox genes

Question 2

What is the role of Homeosis genes?

Answer 2

They transform one body part into another

Question 3

True or False? The genes the establish A-P patterning is similar across many animals.

Answer 3

True

Question 4

All of the homeobox genes are […].

Answer 4

Transcription factors

Question 5

How is the binding for Hox genes amongst common DNA sequences?

Answer 5

Different Hox genes bind common DNA

Question 6

What are the initial domains of homeotic gene expression influenced by?

Answer 6

Gap genes and pair-rule genes

Question 7

WHat maintains the on/off states of the Hox genes?

Answer 7

• Polycomb proteins (repressive)

- Trithorax proteins (activating)

Question 8

How does chromatin structure help maintain the hox pattern?

Answer 8

Trithorax proteins bind DNA to alter chromatin structure

Question 9

How are Hox genes ordered within the chromosome?

Answer 9

The same way they are expressed on the A/P axis

Question 10

True or False? The expression and organisation of Hox genes is conserved in almost all animals.

Answer 10

True

Question 11

What happens when you remove genes from the bithorax complex?

Answer 11

Get mutants in the expression of segments

Question 12

What happens when you use a GOF ubx gene throughout the axis?

Answer 12

Parasegments 1-5 can be transformed into parasegment 6

Question 13

How is it that only three genes can lead to the 10 different segments in the bithorax?

Answer 13

• Antp is in T1 and T2
• If Ubx is removed Anpt goes into T3
• No Ubx with Anpt in T3 leads to wings

Question 14

What is the difference betwwen wing discs and haltere discs?

Answer 14

• Wing discs are regulated by DAPI

- Halter discs are regulated by DAPI + Ubx

Question 15

What does a GOD Antp mutation in the antennal segment cause?

Answer 15

Converts the antenna into a leg