Gene Regulation I and II Flashcards
What effect does DNA methylation have on genes?
Inactivates genes
Demethylation of DNA will _____ genes.
activate
What is the histone acetylation effect on genes?
Activates genes
Most genes are silenced in _______ unless needed to be turned on.
Eukaryotes
Silent for of the chromatin:
heterochromatic
Why is heterochromatin silenced?
Bc:
- DNA in hypermethylation at CpG islands
- Histones are deacetylated.
Define euchromatin:
Active form of chromatin that is transcribed.
What type of chromatin has hypomethylated DNA and acetylated histones?
Euchromatin
Define epigenetics.
Changes in the phenotype without changes in genotype.
Silenced genes have _____ DNA.
Methylated
Active genes have ____ histones.
Acetylated
DNA methylation occurs at _____.
CpG islands
Repressor proteins are attracted to _______.
Methylcytosines
Dosage compensation is managed by:
Different DNA methylation patterns in male and female gametes
Genomic imprinting Dz examples:
Prader-Willi Syndrome
Angelman Syndrome
Chromosome 15 deletion is involved in these Dz.
Prader-Willi Syndrome
Angelman Syndrome
If mutant chromosome 15 is inherited from father, only maternal genes from that region are expressed. What Dz is this?
Prader-Willi Syndrome
In Angelman Syndrome, _____ chromosome 15 is the mutant.
maternal
Whose genes are expressed in Prader-Willi Syndrome?
Maternal genes are expressed
When only the paternal genes are expressed on chromosome 15:
Angelman Syndrome
Methyls for DNA methylation come from:
SAM
What are the classes of Transcription Factors?
- Basal factors
- Activators
- Mediators
- Repressors
- Chromatin modifiers
Name a Helix-Turn-Helix Transcription factor domain:
Homeodomain proteins
Steroid hormone receptors are what type of Transcription Factors?
Zinc Finger