Prader-Willi syndrome is characterized by _____.
obesity, excessive and indiscriminate eating, short stature, small hands and feet, hypogonadism, and intellectual disabilities
genes that are functionally hemizygous because one parental allele is silenced; a sex-dependent epigenetic modulation
The imprinted genes encode both ________ and ________.
proteins and non-coding RNAs
The inherited form of _________ is exclusively inherited from mothers
DNA methylation is maintained in __________.
somatic cells after fertilization
inheriting two copies of a chromosome from one parent, or no copies from one parent
Uniparental disomy most commonly occurs when a trisomic conceptus loses one of its extra chromosomes due to _______.
mitotic nondisjunction in early gestation
What is one sex-dependent epigenetic modulation mechanism?
Angleman Syndrome patients have a deletion of approximately the same region of chromosome 15 as Prader-Willi patients but on the _____ derived homolog.
_________ is characterized by obesity, excessive and indiscriminate eating, short stature, small hands and feet, hypogonadism, and intellectual disabilities.
The 15q11-q13 region contains ____ paternally expressed genes.
Uniparental disomy most commonly occurs when a trisomic conceptus loses _______ due to mitotic nondisjunction in early gestation.
one of its extra chromosomes
Demethylation could result from the inhibition of _____, or indirectly through the inactivation of chromatin-remodeling proteins.
the maintenance methyltransferase, DNMT1
How many human genes are imprinted?
How does CpG methylation affect gene expression?
chromatin structure is compacted to repress transcription
DNA methylation is established _________.
in the gamete
DNA methylation is the epigenetic mark that mediates __________.
Which chromosome is mutated to result in Prader-Willi and Angleman Syndrome?
To accomplish such epigenetic inheritance, parental patterns of methylation are erased in ______ as part of overall genomic reprogramming.
primordial germ cells
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
15q11-13 locus relevance
uniparental disomy - Prader-Willi and Angelman Syndrom
________ could result from the inhibition of the maintenance methyltransferase, DNMT1, or indirectly through the inactivation of chromatin-remodeling proteins.
mitotically and meiotically inheritable variation in gene expression that is not caused by a change in DNA sequence
In addition to parent of origin effects due to deletions, genetic imprinting also leads to abnormal phenotypes in association with ______.
Imprinted gene clusters contain both _____ and ______ imprinted genes.
maternally and paternally
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 _______.
Which trisomies can survive to live birth?
13, 18, and 21
DNA methylation is __________ so that it can be reset during gametogenesis.
Erasure and resetting of the imprint appears to occur at _______.
imprinting centers (IC)
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