Epigenetics 4

Question 1

What does too much stem cell self renewal cause?

Answer 1

Hyperplasia

Question 2

What does too much stem cell differentiation cause?

Answer 2

Small organs

Question 3

In asymmetric division, what do neural stem cells in drosophila divide to produce?

Answer 3

Self renew and ganglion mother cell

Question 4

What is polarity in stem cell division?

Answer 4

Apical and basal alignment of protein during division

Question 5

Does prospero align in the basal or apical cortex during asymmetrical division of stem cells?

Answer 5

Basal

Question 6

What is DAM ID?

Answer 6

Attach DNA binding protein to E.coli enzyme which methylates adenine at GATC sites. Sites of methylated adenine indicate binding site of protein (e.g. prospero/lola)

Question 7

What region of cyclin E gene does prospero bind?

Answer 7

introns

Question 8

What did an RNA seq expression array reveal that prospero repressed?

Answer 8

neutral stem cell genes e.g. cyclin E

Question 9

What happens to stem cells when prospero is knocked out?

Answer 9

Continuation of self renewal

Question 10

What sequence was found conserved near prospero binding sites?

Answer 10

GATCG - binding site for lola

Question 11

What binds the DNA sequence GATCG?

Answer 11

lola

Question 12

What was used to identify lola as the DNA binding protein of sequence GATCG?

Answer 12

yeast 1 hybrid using His-3 marker protein

Question 13

What is the structure of lola?

Answer 13

BTB zinc finger

Question 14

What is the role of lola?

Answer 14

Transcription factor

Question 15

What is the role of prospero?

Answer 15

Transcription factor

Question 16

How many isoforms of lola were found?

Answer 16

25

Question 17

How many isoform of lola that have zinc fingers were there?

Answer 17

17

Question 18

What kind of cell is lola expressed in?

Answer 18

Post mitotic neurons in drosophila

Question 19

Do most lola targets overlap with prospero targets?

Answer 19

yes

Question 20

What is the function of lola?

Answer 20

To maintain a cell in a differentiated state by repressing neural stem cell genes. It also represses genes that have already been switched off by prosper

Question 21

What happened when MARCM was used to knock out lola in drosophila?

Answer 21

tumour formation because of dedifferentiation of cells

Question 22

Can removal of lola causes dedifferentiation of mature neurons?

Answer 22

No, this is controlled by other factors interacting with lola

Question 23

What was used to identify binding partners of lola?

Answer 23

yeast 2 hybrid screen - found over 100 hits

Question 24

Give example of factors that interact with lola to prevent dedifferentiation?

Answer 24

NuRD complex
Histone deacetylates
permanently repress even when lola is removed

Question 25

What were 60% of lola hits from the yeast 2 hybrid screen?

Answer 25

lncRNAs

Question 26

Is lncRNA segregated into GMC in the same way as prospero?

Answer 26

yes

Question 27

What was lncRNA found to express?

Answer 27

micro-peptide 1

Question 28

How many many amino acids in micro-peptide- 1?

Answer 28

30aa

Question 29

What is the function of micro-peptide 1?

Answer 29

interacts with lola to prevent it from acting too early in differentiation

Question 30

What is the hippo pathway?

Answer 30

Cascade that results in repression of Yorkie (YAP)

Question 31

What does overexpression of yorkie (YAP) cause?

Answer 31

more proliferation of epithelium cells

Question 32

What has been found up regulated in melloblastomas?

Answer 32

YAP

Question 33

Yorkie causes symmetric division of stem cells. True or false?

Answer 33

True

Question 34

What is the affect of hippo pathway on symmetrical divsion of stem cells?

Answer 34

inhibitory - blocks yorkie (YAP)

Question 35

What is the notch pathway?

Answer 35

Delta ligand on one cell interacts with notch receptor on another. Causes gamma-secretase to cleave the intracellular region of notch (Rbpj) which translocates to the nucleus and promotes symmetrical division of stem cells

Question 36

What is the affect of notch pathway on symmetrical divsion of stem cells?

Answer 36

promotes symmetrical division

Question 37

Is notch a proto-oncogene?

Answer 37

yes

Question 38

What is the affect of KO Rbpj?

Answer 38

more asymmetric division, reduced size of cortex

Question 39

How does notch suppress growth?

Answer 39

different cellular context

Question 40

Could gamma-secretase inhibitors be a potential theraputic?

Answer 40

yes