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Flashcards in epigenetics Deck (24)
1

effects of paternal grandparent diet on children

poor diet decreased mortality rate

2

Genetically comparable mothers who were fed slightly different diet (low or high "methyl donor" ingredients) during gestation and nursing produced very different offspring

The AGOUTI gene is turned off in the darker, smaller mouse. Agouti protein regulates both coat color and feeding habits.
Methyl donor ingredients:
folic acid, vitamin B12, choline, betaine
High MD mother: skinny
Low MD mother: Fat

3

epigenetic changes lead to

diversity of cell types

4

Epigenetic Characteristics: A Definition:

1) Different gene expression pattern/phenotype, identical genome
2) Inheritance through cell division, even through generations
3) like a switch: on/off
4) erase-abe (interconvertibel) THERAPEUTIC POTENTIAL

5

flipping switches as a visualization of

epigenetic gene expression pattern

6

differentiated cell has lights

partially on

7

induced pluriotpoten stem cell has lights

all turned on

8

Why is erasure and resetting of methylation patterns of imprinted genes during gametogenesis esstenial?

imprinting! so not all male gametes have the same expression, nor do female gametes, so you turn them all on then silence so that no matter the combination, it works

9

proper imprinting

1. meiosis
2. erasure: DNA de-methylation
3. Sex-specific gene silencing: DNA methylation
4. fertilization

10

DNA methyltion locks in the

repressed state

11

DNA methylation occurs only on

cytosines of CpG

12

DNA methylation does not affect the

base paining of 5-meC with G

13

DNA methylation contributes to

gene silencing by solidifying the repressed state. It uses a cofactor to do this. The cofactor makes this work at a higher capacity

14

Maintenance methytransferase propagates

epigenetic marks throughout somatic cell division
new strands lack the methyl group, so this recognizes and methylates the new strands

15

histone H3 modifications

affect gene expression
the repressive histone mar can be off: with no Ac
Or ON, which Ac on the DNA

16

Problem for maintaining an epigenetic state (DNA methylation or histone mod.):

- DNA is half old/half new
- Histones are half old/half new

17

examples of epigenetic phenomena:

1. chromatin-mediated gene silencing
2. centromere marking by histone variant CENP-A
3. Prions
4. Reinforceing feedback loops involving trans-acting factors that have a specific initiation event and are "inherited" in cytosol during cell division

18

Reinforceing feedback loops involving trans-acting factors that have a specific initiation event and are "inherited" in cytosol during cell division

1. bacteriophage lambda repressor mechanism
2. feedback loops in the initiation of certain cancers that operate through cytosolic signaling proteins and miRNA

19

chromatin-mediated gene silencing

heterochromatin domains
X-inactivation
imprinting

20

cytosolic epigenetic inheritance in cancer is an example of

non-nuclear epigenetics

21

silencing of tumor suppressor gene (TSG) by

5meC can lead to cancer

22

correcting epigenetic patterns as a cancer therapy

prevetning inheritance of aberrant gene silencing
DNA methyltrasnferase and HDAC inhibition can inhibit tumor genes
interconveratable states, can drug a system to reset cells to a normal state and reset homeostasis

23

3 chemical modifications to DNA

1. methylation (imprinting)
2. heterochromatin domains (HATs an HDAC)
3. x inactivation

24

diseases of epigenetic phenomena

1. angelman
2. prader wili