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M2M Unit II > Genetic Imprinting > Flashcards

Flashcards in Genetic Imprinting Deck (48)
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1

Prader-Willi syndrome is characterized by _____.

obesity, excessive and indiscriminate eating, short stature, small hands and feet, hypogonadism, and intellectual disabilities

2

imprinting

genes that are functionally hemizygous because one parental allele is silenced; a sex-dependent epigenetic modulation

3

The imprinted genes encode both ________ and ________.

proteins and non-coding RNAs

3

The inherited form of _________ is exclusively inherited from mothers

Angelman syndrome

4

DNA methylation is maintained in __________.

somatic cells after fertilization

4

uniparental disomy

inheriting two copies of a chromosome from one parent, or no copies from one parent

4

Uniparental disomy most commonly occurs when a trisomic conceptus loses one of its extra chromosomes due to _______.

mitotic nondisjunction in early gestation

6

What is one sex-dependent epigenetic modulation mechanism?

imprinting

6

Angleman Syndrome patients have a deletion of approximately the same region of chromosome 15 as Prader-Willi patients but on the _____ derived homolog.

maternally

7

_________ is characterized by obesity, excessive and indiscriminate eating, short stature, small hands and feet, hypogonadism, and intellectual disabilities.

Prader-Willi syndrome

7

The 15q11-q13 region contains ____ paternally expressed genes.

three

7

Uniparental disomy most commonly occurs when a trisomic conceptus loses _______ due to mitotic nondisjunction in early gestation.

one of its extra chromosomes

7

Demethylation could result from the inhibition of _____, or indirectly through the inactivation of chromatin-remodeling proteins.

the maintenance methyltransferase, DNMT1

9

How many human genes are imprinted?

about 1%

11

How does CpG methylation affect gene expression?

chromatin structure is compacted to repress transcription

11

DNA methylation is established _________.

in the gamete

13

DNA methylation is the epigenetic mark that mediates __________.

genetic imprinting

14

Which chromosome is mutated to result in Prader-Willi and Angleman Syndrome?

15

15

To accomplish such epigenetic inheritance, parental patterns of methylation are erased in ______ as part of overall genomic reprogramming.

primordial germ cells

16

The chromosomal sorting error in uniparental disomy “rescues” the developing pregnancy from spontaneous abortion but may result in an abnormal phenotype if both remaining homologs are derived from _______.

the same parent

16

15q11-13 locus relevance

uniparental disomy - Prader-Willi and Angelman Syndrom

17

________ could result from the inhibition of the maintenance methyltransferase, DNMT1, or indirectly through the inactivation of chromatin-remodeling proteins.

Demethylation

18

epigenetic

mitotically and meiotically inheritable variation in gene expression that is not caused by a change in DNA sequence

18

In addition to parent of origin effects due to deletions, genetic imprinting also leads to abnormal phenotypes in association with ______.

uniparental disomy

20

Imprinted gene clusters contain both _____ and ______ imprinted genes.

maternally and paternally

21

In uniparental disomy, if both remaining 15 homologs are maternal in origin, both carry maternally repressed loci, but normal development is dependent on expression of genes at the missing _______.

paternal locus

21

Which trisomies can survive to live birth?

13, 18, and 21

22

DNA methylation is __________ so that it can be reset during gametogenesis.

reversible

23

Erasure and resetting of the imprint appears to occur at _______.

imprinting centers (IC)

24

What would happen if methylation marks are not erased during gametogenesis?

total silencing of both copies of the gene would occur at a very high rate