BIOL308 Lecture Notes - Lecture 5: Locus Control Region, Deoxyribonuclease I, Scaffold Protein
16 May 2017
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Types: euchromatin: open structure, transcriptionally active, can be dnase 1 digested, heterochromatin: closed structure, transcriptionally inactive, can be dnase 1 digested. Constitutive: very condensed, inactive, repetitive dna, few genes (telomere, centromere) Facultative: not active in particular tissue and forms to silence expression (dna methylation) or in specific circumstances (genomic imprinting from epigenome) Chromatin elements: locus control regions: upstream from genes that control chromatin condensation. Hypersensitive sites: sensitive to nuclease attack: scaffold associated regions: at rich dna which anchors to the nuclear matrix, insulators: protein factors - regulatory domains which define the domains of gene expression. The regions in between insulators is dna that will be transcribed (on the edges of which are heterochromatin so those genes aren"t transcribed: centromere: which are a site attachment for microtubules and sister chromatids. 3" end is longer and not flush with the 5" end so the sequence is continuously synthesized and degraded.
