TBL 4 Flashcards
What is the study of gene regulatory mechanisms which do not directly involve the DNA sequence?
Epigenetics
The effect of methylation in CpG islands on gene regulation is usually:
Silencing
The five epigenetic mechanisms are:
DNA methylation Histone modification ATP-Dependent chromatin remodeling Histone variants Noncoding RNA
The effect of histone acetylation on DNA regulation is usually:
Activation
DNA methylation is regulated by enzymes called:
DNA methyltransferases
DNA methylation has ___ symmetry
dyad
Following replication, methylations are copied onto the new DNA strand by:
maintenance methyltransferase
In a spontaneous mutation from C to U, what repair mechanism replaces the U in DNA?
Base Excision Repair
What are the two most common mutations at CpG’s?
C to T
G to A
Deamination of 5’-methyl-cytosine leads to:
Thymine
What gene is mutated in Rett Syndrome?
MeCP2
One example of a DNA Methyltransferase used in transcriptional repression is:
DNMT1
One example of a methyl-binding domain protein used for transcriptional repression is:
MeCP2
What is the mechanism in which only certain genes from the allele found on a chromosome from a specific parent is:
Genomic imprinting
Which allele is imprinted, the on that is turned off or left on?
Turned off (methylated)
If a mutant gene is on the imprinted allele, will the disease be expressed?
No
What is the disease which causes slow growin, mostly benign tumors of the parasympathetic ganglia, usually in the head/neck?
AD Paraganglioma (Glomus Tumors)
Which parent is AD paragangioma inherited from? Why?
Father, maternally imprinted, paternally expressed
Imprinted genes (and mutations in them) will result in a ___-of-origin effect
Parent
Profound MR, happy demeanor, seizures, ataxia, and absent speech are symptoms of:
Angelman Syndrome
Lack of maternal contribution of 15q11-13 is affiliated with:
Angelman Syndrome
The UBE3A gene is associated with:
Angelman Syndrome
Angelman Syndrome is associated wth the gene:
UBE3A
Angelman syndrome is associated with a lack of paternal/maternal contribution to the ____ chromosomal region
Maternal, 15q11-13
Hypotonia, failure to thrive, hyperphagia, obesity, hypopigmentation (variable), and mental retardation are symptoms of:
Prader-Willi Syndrome (PWS)
Do patients of PWS have a normal karyotype?
Yes
Prader-Willi Syndrome is associated with a lack of paternal/maternal contribution to the ____ chromosomal region
Paternal, 15q11-13
Important genes in PWS include:
SNRPN and OCA2
SNRPN is expressed from the ___ chromosome. What type of imprinting is this?
paternal, maternal imprinting
UBE3A is expressed from the ___ chromosome. What type of imprinting is this?
maternal, paternal imprinting
What has to occur to result in uniparental disomy?
Meiotic and mitotic nondisjunction resulting in trisomy rescue and a 1/3 chance of UD
Heterodisomy must have occurred in:
Meiosis 1
Isodisomy must have occurred in:
Meiosis 2
