Final: Epigenetic Inheritance Flashcards Preview

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Flashcards in Final: Epigenetic Inheritance Deck (26)
1

adult cells are highly _____

differentiated states with specific genes turned on or off

2

when an adult cell divides...

it passes on the status of every gene to daughter cells

3

5 aspects of gene regulation passed on

histone variants and modifications

DNA modifications (methylation of cytosines)

chromatin binding proteins (TFs)

chromatin structural RNA

4

genetic inheritance

a dividing cell passes on its genes to daughter cells

this means the DNA sequence only

5

epigenetic inheritance

a dividing cell also passes on the regulatory status of each gene

all regulatory mechanisms are passed on to daughter cells

6

what is a barr body an example of

epigenetic inheritance

barr body replicates and is passed on, then turns into a barr body again

7

how do daughter cells stay the same as parent cells?

the genes "remember" what they were doing before

so they keep doing it in the daughter cells

epigenetic inheritance

8

4 things the daughter cells end up having

same histone modifications

same cytosine methylations

same bound TFs

same bound regulatory RNA

9

2 pathways to epigenetic inheritance

from cell to cell within a body

from parent to offspring between generations

10

genomic imprinting

parent-to-child epigenetic inheritance

causes the same allele to have different effects

effect depends on the sex of the parent transmitting the allele

same gene can be "pre-methylated" two different ways in eggs or sperm

11

DMR

differently methylated region

regions of DNA that are methylated one way in eggs and another way in sperm

12

genomic imprinting occurs in the ____

germline

offspring grows up keeping the methylation pattern of parents

parental imprinting is erased in germline of offspring

then the genes are re-imprinted according to the offspring's own sex

13

CpG island

genomic imprinting in mammals involves methylation of CpG islands

there may be additional mechanisms for epigenetic inheritance in gametes

14

IGF2

protein hormone that promotes fetal growth

mother's copy is shut down by methylation

father's copy does all the work

it doesn't matter if the mother's copy gets mutated

if father's copy is mutated then you don't grow right

15

Beckwith Wiedemann Syndrome

same genes are in mice chromosome 7 and human 11

loss of mother's copy causes BW syndrome

paternal homolog already shut down

16

Prader Willi Syndrome and Angelman Syndrome

2 genetic diseases coming from 1 genetic region

PW leads to extreme appetite and obesity

Angelman leads to hyperactivity

to be normal, inherit one imprinted copy of DMR from each parent

17

how get Prader Willi

inherit only mothers DMR

18

how get Angelman

inherit only fathers DMR

19

causes of Prader Willi

paternal deletion

paternal methylation defect

maternal uniparental disomy (2 copies of maternal #15)

20

causes of Angelman

maternal deletion

maternal methylation defect

paternal uniparental disomy (2 copies of paternal #15)

21

uniparental disomy

a person has normal diploid # of chromosomes (46)

but for one pair of homologs, both copies came from just 1 of the parents

22

how does uniparental disomy occur

trisomic zygote sorts into disomy in early division of embryo

disomic gamete could meat a nullisomic gamete

monosomic zygote duplicates in early division

23

DMRs

to be normal you need:

one haploid set of male imprinted chromosomes

one haploid set of female imprinted chromosomes

24

all mammals use genomic imprinting but not on all ____

genes

25

most genes are not in ___, so these problems dont arise with them

DMRs

26

can environmental factors negatively affect genomic imprinting?

yes: in vitro fertilization multiplies rate of BW syndrome 3-4x

also: exposing pregnant rats to fungicide Vinclozolin causes epigenetic effects

passed on several generations but only in males