SC - The Structure and Function of the Genome Flashcards
(14 cards)
What are Chromosomes Territories (CTs)?
Domains occupied by chromosomes within the nucleus
How would you describe the distribution of chromosomes?
Non-random
What is CT position correlated with?
Gene content
Where in the nucleus would more active chromosomes lie?
Interior
What do interphase chromosomes contain?
Regions of:
- CLOSED chromatin- Heterochromatin
- OPEN chromatin- Euchromatin
Describe the features of Heterochromatin?
COMPACT and NOT TRANSCRIBED
Describe the features of Euchromatin?
RELAXED and TRANSCRIBED
What CT is known to hold/separate ‘open’ and ‘closed’ chromatin?
Topologically-Associated Domains (TADs)
What determines the eu- or hetero- chromatin state?
Histone Modifications
(Amount of methyltion vs acetlylation determines open vs closed)
What are 2 Histone-modifying enzymes?
Histone AcetylTransferases (HATs)
- Transfer ‘acetyl’ groups onto histone tails
Histone MethylTransferases (HMTs)
- Transfer ‘methyl’ groups onto histone tails
Why are cells different if they have the same DNA?
- Differential chromatin state
- Differential coding gene expression
- Differential non-coding gene expression
What are mutations within the non-coding region identified as?
Pathogenic
Out of cis-acting and trans-acting non-coding elements, which one is transcribed and made into RNA?
Trans-acting (Regulatory RNAs, Structural RNAs)
Not Cis-acting (Enhancers, Silencers, Telomeres, Centromeres, Insulators)
What are the 2 types of non-coding RNA?
Long Non-Coding RNAs (lncRNAs)
- Longer than 200nt
- Contain poly-A tails
Small Non-Coding RNAs (ncRNAs)
- Shorter than 200
- Contain poly-A tails
- Mainly regulatory
