Epigenetics

Question 0

Epigenetic mechanism

Answer 0

• DNA methylation
• Chromatin structure and histone modification
• Transmitted RNAs and proteins
• Prions

Question 1

What is epigenetics?

Answer 1

Heritable changes that are not caused by changes in the DNA sequence

Question 2

DNA methylation

Answer 2

In vertebrates, most DNA methylation occurs at cytosines in CpG dimers
~75% of such cytosines are methylated
It occurs in other contexts like embryonic stem cells

Catalyzed by DNA methyl transferase

Question 3

Chromatin structure

Answer 3

Highly structured complex of DNA and protein

148 bp of DNA
2 copies each of histones 2A, 2B,, 3 and 4

Connected by stretches of
Linker DNA which ~75 bp

Question 4

Simplest component of chromatin

Answer 4

Nucleosome

They are further arranged into 30 nvm fibers, which are progressively compacted into euchromatin and heterochromatin

Question 5

Histone modification

Answer 5

Post translational modification of histone proteins

Exames: methylation and acetylation of specific lysine in instructured N terminal tials of histones h3 and h4

Question 6

Histone modifiers

Answer 6

Histone acetyltranferases
Histone deactylases
Histone methyltransferases

Question 7

HATs

Answer 7

Histone acetyltranferases

Example: p300 and gnats

Question 8

HDACs

Answer 8

Histone deactylases

More than 4 classes

Question 9

HMTs

Answer 9

Histone methyltransferases

SETs and arginine specific HMTs

Question 10

DNA methylation experimental techniques

Answer 10

Bisulfite sequencing

SMRT sequencing

Question 11

Histone modifications experimental techniques

Answer 11

Chip seq

Question 12

Genetics experimental techniques

Answer 12

Heritability of DNA methylation

Somatic mutations studies