Epigenetics

Question 1

What is a genome?

Answer 1

A complete set of inherited genetic information.

Question 2

What is mosaicism?

Answer 2

The property or state of being composed of cells of two genetically different types.

Question 3

What are single cell genomics?

Answer 3

Map the transcriptomics of the whole body.

Question 4

What is a phenotype?

Answer 4

Genes interacting with the environment for presenting characteristics?

Question 5

Why do the genotype and the phenotype differ?

Answer 5

Because the genome can be read differently to give a different phenotype.

Question 6

What makes a genome more complex?

Answer 6

Introns

Question 7

What is the phenotype controlled by?

Answer 7

Gene regulation

Question 8

What is the regulatory DNA?

Answer 8

Nucleic acid sequence capable of either increasing or decreasing expression of a gene

Question 9

What is the role of regulatory DNA?

Answer 9

Operate as ‘post codes’ for the assembly of protein complexes that control the rate of transcription

Question 10

How is a regulatory complex formed?

Answer 10

Chromatin loops over to joining enhancers and promoters

Question 11

What happens when you replace the DNA in a fibroblast?

Answer 11

When MYOD is inserted it becomes a muscle cell.

Question 12

Why does inserting MYOD into a fibroblast change it’s cell type?

Answer 12

Activates a present but not functional Transcription factor allowing for new information to be transcribed.

Question 13

What are epigenetics?

Answer 13

Heritable changes in phenotype or gene expression caused by mechanisms other then changes in the underlying DNA sequence

Question 14

What are the 2 types of chromatin?

Answer 14

Heterochromatin

Euchromatin

Question 15

What is heterochromatin?

Answer 15

Closed chromatin conformation , no transcription

Question 16

What is eurochromatin?

Answer 16

Open chromatin conformation, transcription occurs

Question 17

How does chromatin open?

Answer 17

Histone Lysine Acetylation Relaxes (Opens) Chromatin

Question 18

Why does transcription stop when chromatin is deacetylated?

Answer 18

Tails stick out and can be seen by enzymes.

Question 19

How does acetylation change chromatin position?

Answer 19

Positive-charged lysines are attracted to negative-charge DNA

Acetylation masks the negative charge which repels DNA to “open” chromatin.

Question 20

What else can histone lysine acetylation do?

Answer 20

Write

Erase

Read

Question 21

How is histone lysine acetylation used to read DNA?

Answer 21

Binds to the acetyl group epigenetic markers allowing for the enzyme to attach.

Question 22

What happens to histone acetylation in cancer and why is that important?

Answer 22

Becomes dysregulated, and this allows for it to be a target for drugs.

Question 23

How is lysine methylation a gene regulator/

Answer 23

Doesn’t turn the gene off completely however but can speed up or slow down DNA replication or expression.

Question 24

What is HMT?

Answer 24

Histone methyltransferase

Question 25

What is HDM?

Answer 25

Histone demethylase

Question 26

What is the problem with jumping genes?

Answer 26

Must be switched off because they replicate like crazy

Question 27

What are CpG regions?

Answer 27

Promotor regions which can be used as an epigenetic platform.

Question 28

What happen when aberrant methylation occurs at CpG islands?

Answer 28

Cancer

Question 29

What is the role of DNA methyltransferases (DNMTs)?

Answer 29

Writers

Question 30

What is the role of Ten-eleven translocation (Tet) proteins?

Answer 30

Erasers

Question 31

What is the role of Methyl-Domain binding (MBDs) proteins?

Answer 31

Readers

Question 32

What is the role of CG binding proteins?

Answer 32

Readers

Question 33

What is the agouti mouse?

Answer 33

Has unmethylated DNA which leads to the mouse being yellow and obese and later gets cancer and dies much younger.

Question 34

What vitamin is used for methylating DNA?

Answer 34

Folic acid

Question 35

What reduces the methylation in DNA?

Answer 35

Bisphenol A

Question 36

What is somatic cell divsion?

Answer 36

Daughter cells inherit their DNA methylome.

Question 37

What is somatic cell division regulated by?

Answer 37

The maintenance enzyme DNMT1.

Question 38

What is the advantage of somatic cell divison?

Answer 38

Enables the regeneration of specific cell types

Question 39

What is the germ-plasm or Weismann Barrier theory?

Answer 39

Somatic cells do not function as agents of heredity. The flow of genetic information is one-way from ger plasm to soma, this cannot be reversed.

Question 40

What kind of epigenetic inheritance is there?

Answer 40

Intergenerational transmission Multigenerational transmission Transgenerational transmission

Question 41

What is intergenerational transmission?

Answer 41

Exposure leads to change in phenotype in children.

Question 42

What is multigenerational transmission?

Answer 42

Exposure leads to changes in phenotype in children and grandchildren.

Question 43

What is transgenerational transmission?

Answer 43

Exposure leads to changes in phenotype in children, grandchildren, and subsequent generations to exposed to initial insult.

Question 44

Does the epigenetic transmission of phenotypes change the gene sequence?

Answer 44

NO

Question 45

What are the developmental epigenetic barriers?

Answer 45

Two developmental phases where DNA methylation is “erased” and reprogrammed

Question 46

What are the 2 developmental phases where DNA methylation is “erased” and reprogrammed?

Answer 46

When primordial germ cells are being proliferated and are migrating to become oocytes. When the zygotes divide after fertilization.

Question 47

How is DNA methylome analysis carried out?

Answer 47

Laser dissection gDNA extraction Bisulphite conversion to reveal mCpGs Deep sequencing

Question 48

What is bisulphite sequencing?

Answer 48

Identify and quantify methylated DNA.