Epigenetics

Question 0

Acetylation enzymes? What gets acetylated?

Answer 0

of histone

• HAT acetylates lysine
• HDAC deacetylates

Question 1

Where on DNA does methylation occur?

Answer 1

CpG island cytosine

Question 2

DMR

Answer 2

differentially methylated regions

occurs within an imprinted region (different methylation patterns)

Question 3

Imprinting disease example

Answer 3

15q11. 2 mutation –> 2 different syndromes
- normal: maternal strand has methylation that allows for UBE3A expression; paternal strand has no methylation
- Prader-Willi: paternal alleles not expressed (del, maternal UPD, paternal methylation)
- Angelman: loss of UBE3A (del, LOF at UBE3A, no methylation, paternal UPD)

Question 4

somatic mosaicism mechanisms

Answer 4

long ncRNA coats X gene –> inactivation

Question 5

miRNA in epigenetics?

Answer 5

miRNA binding –> reduced transcription
regulated by CpG island methylation
target for cancer therapy

Question 6

piRNA role in epigenetics

Answer 6

transcriptional silencing during spermatogenesis