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