Genome Organisation and Function

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What is the term for the physical compaction of genomes where each chromosome has its own 'space or neighbourhood' within the nucleus?

Chromosomal segregation

Spatial chromatin organization (correct)

Nuclear zoning

Genomic condensation

Which area of a chromosome is generally genetically active?

Nuclear periphery chromatin

Euchromatin (correct)

Nucleolus-associated chromatin

Heterochromatin

What do interphase chromosomes occupy within the nucleus?

Random positions

Interconnected webs

Discrete territories (correct)

Concentric rings

What is the term for the evolutionarily controlled process of packaging DNA into a particular space within the nucleus?

Nuclear compaction Signup and view all the answers

Which protein associates with the Stag protein of cohesin?

Rad21 Signup and view all the answers

What is the chromatin residence time of cohesin?

20 minutes Signup and view all the answers

What results from the loss of insulation between TADs after cohesin and CTCF knock-down?

Decrease in intra-TAD contact frequency Signup and view all the answers

What model supports the theory of 'stable' TAD structures?

Cohesin loading and dissociation model Signup and view all the answers

What forms between convergent CTCF sites, thus regulating structure specificity?

DNA loops Signup and view all the answers

Which factor does NOT localise at CTCF sites, suggesting cohesin must travel on chromatin to reach CTCF?

Nipbl Signup and view all the answers

What is associated with transient loops within TADs (intra-TAD DNA loops) and influences specific gene expression?

Cohesin-Mediator complex association Signup and view all the answers

Which technique highlights the co-localisation of cohesin and CTCF at TAD boundaries?

Chromatin Conformation Capture techniques Signup and view all the answers

What can Cohesin associate with to influence specific gene expression?

Transcription Factors localising Cohesin Signup and view all the answers

What do Population-based Chromatin Conformation Capture techniques create?

An average of most ‘stable’ domain structure. Signup and view all the answers

What is the function of cohesin during the G1 phase?

Associates with single-stranded chromatin to form loop structures that are essential for genome organization and cell-specific gene expression Signup and view all the answers

What can methylation of a CTCF site dictate?

Ability of cohesin to interact with DNA in trans and cis Signup and view all the answers

What is the role of topologically associated domains (TADs)?

Creating domains of topological association of high interaction frequency Signup and view all the answers

What do enhancers do in the context of long-range gene regulation?

Can be involved with multiple promoters both simultaneously and sequentially Signup and view all the answers

What is the biological importance of TADs/structure?

DNA replication, recombination, gene regulation Signup and view all the answers

What is the function of CTCF during the G1 phase?

Recognises 11 nucleotides only when facing a particular way and sitting on the right place, where the cohesin ring can hold Signup and view all the answers

What does cohesin do during DNA replication?

Associates with single-stranded chromatin to form loop structures that are essential for genome organization and cell-specific gene expression Signup and view all the answers

'CTCF Code': x11 Zinc Finger protein gives multivalence to CTCF's recognition sequence, which fine-tunes its insulator 'strength'. What does this statement imply?

'CTCF Code' recognizes 11 nucleotides only when facing a particular way and sitting on the right place, where the cohesin ring can hold Signup and view all the answers

What are the functions of TADs?

Act as a chromatin barrier between TADs, creating insulation to TAD contacts Signup and view all the answers

What is the role of enhancers in long-range gene regulation?

Can be brought into close proximity physically so that expression can be driven which wasn’t close to the gene before Signup and view all the answers

What dictates the ability of cohesin to interact with DNA in trans and cis?

'CTCF Code': x11 Zinc Finger protein gives multivalence to CTCF's recognition sequence Signup and view all the answers

What does methylation of a CTCF site protect from?

Binding of Zinc Fingers 4-7 cluster together to conserved insulator (CRE) consensus sequence CCGCGNGGNGGCAG Signup and view all the answers