W10 L2

Question 1

What genes are highly conserved?

Answer 1

toolkit genes

Question 2

What are toolkit genes?

Answer 2

genes responsible for an organism’s embryonic development

Question 3

What do hox genes regulate?

Answer 3

expression of developmental genes and have collinearity

Question 4

What do all hox genes share?

Answer 4

A 180 bp sequence called the homeobox

Question 5

What does the homeobox code for?

Answer 5

sequence of 60 aa that form the homeodomain

Question 6

What is the homeodomain?

Answer 6

A DNA binding motif that allows for various transcription factors that these genes code for to bind with promoter regions of their target genes

Question 7

When did the first duplication event of the Hox genes occur?

Answer 7

around the start of vertebrate evolution

Question 8

When did the second hox gene duplication event occur?

Answer 8

around the time of Gnathostome evolution because all have 4 clusters instead of 2

Question 9

When did the 3rd and 4th Hox gene duplication event occur?

Answer 9

3rd event: advent of teleost fishes

4th event: salmonid fishes

Question 10

Where is the SHH protein expressed in the vertebrate limb bud?

Answer 10

zone of polarizing activity

Question 11

What does the SHH protein control in vertebrate limb bud?

Answer 11

the axis of distal parts of the limbs

Question 12

What is hypermorphosis?

Answer 12

growth doesn’t stop and structure ends up larger

Question 13

What’s hypermorphosis in mice?

Answer 13

over expression of Lin28a in mice lead to mice with larger tails

Question 14

Is somites an example of a module?

Answer 14

YES

Question 15

What does a network of genes and gene products cause in the pre-somatic mesoderm cells?

Answer 15

causes those cells to oscillate between a permissive and non-permissive state in a consistently timed fashion like a clock

Question 16

How does the wavefront progress in somitogenesis?

Answer 16

anterior to posterior

Question 17

What happens when the wavefront comes into contact with cells in the permissive state during somitogenesis?

Answer 17

the cells undergo a mesenchyma-epithelial transition and pinch off of the more anterior pre-somatic mesoderm.

Question 18

What does the pinching off of the more anterior pre-somitic mesoderm form?

Answer 18

a somite boundary and resets process fro the next somite

Question 19

When does evolutionary novelty originate?

Answer 19

when part of the body acquires individuality and quasi - independence

Question 20

What does the evolutionary novelty involve?

Answer 20

origin of a new character identify rather than character state

Question 21

What is the characteristic of a parts within the module?

Answer 21

highly non independent

a change in one part strongly affects the others

Question 22

what is the relatiobship between different modules?

Answer 22

they are more independent from each other