epigenetics

Question 1

what is epigenetics

Answer 1

study of how the genotype and environment act together to make up the phenotype

Question 2

examples of epigenetics

Answer 2

why identical twins aren’t actually identical
stress memory improving drought tolerance
inherited fear behaviour in rats

Question 3

does epigenetics entail a change in DNA sequence

Answer 3

no

Question 4

types of epigenetic modification

Answer 4

• histone modification
• DNA methylation
• non-coding RNAs

Question 5

how many histone modifications are known

Answer 5

100

Question 6

types of histone modification

Answer 6

• methylation
• acetylation
• citrulination
• phosphorylation
• ubiquination

Question 7

in H3K27me3, what is represented by the H3

Answer 7

histone iD

Question 8

in H3K27me3, what is represented by the K

Answer 8

amino acid iD

Question 9

in H3K27me3, what is represented by the 27

Answer 9

AA position on tail

Question 10

in H3K27me3, what is represented by the me3

Answer 10

chemical modification

Question 11

histone modifications have different outcomes depending on:

Answer 11

• modification itself
• genomic location of mod
• presence of other modifications on same genomic location

Question 12

what enzyme is involved in DNA methylation in mammals

Answer 12

DNA methyltransferase

Question 13

what base is most often methylated

Answer 13

C

Question 14

genomic regions rich in CpG prone to methylation are known as and are often associated with

Answer 14

CpG islands associated with promoter regions

Question 15

what is the usual effect of DNA methylation

Answer 15

inhibit gene expression

Question 16

are non-coding RNA’s direct or indirect modulators of epigenetic regulation

Answer 16

both

Question 17

what treatment is used to detect DNA methylation and how does it work

Answer 17

bisulfite treatment
converts non-methylated cytosine into thymine

Question 18

what is used to detect DNA-protein interaction (histone modifications)

Answer 18

chromatin immunoprecipitation (ChIP)

Question 19

what are the steps of chromatin immunoprecipitation (ChIP)

Answer 19

1. crosslink DNA proteins and isolate
2. immunoprecipitate with specific antibody
3. remove crosslinks and purify DNA
4. peak calling

Question 20

what is the role of the last step (peak calling) in ChIP

Answer 20

identify regions of the genome associated with specific histone modifications

Question 21

what method is used to detect non-coding RNA (steps)

Answer 21

1. extract total RNA
2. enrich ncRNAs
3. high throughput sequencing
4. align to genome or ncRNA sequences
5. annotate and quantify ncRNAs

Question 22

what are the benefits of stress memory in plants

Answer 22

protection against future stress
local acclimation to changing environment