KSH 0611 Review Epigenetic modifications regulate gene expression
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Revision as of 01:43, 11 June 2016 by imported>Seung-hoon Kim
Contents
- 1 Epigenetics
- 1.1 Definition : Heritable changes in gene activity and expression that occur without alteration in DNA sequence
- 1.2 Two well-known epigenetic modifications
- 1.3 Why is it important ? >>> Epigenetic modifications regulate gene activity and expression during development and differentiation, or in response to environmental stimuli
- 1.4 Epigenetics is considered a bridge between genotype and phenotype
- 1.5 Explain how cells carrying identical DNA differentiate into different cell types >>> Epigenetics
- 1.6 Epigenome - global analyses of epigenetic markers across the entire genome
- 1.7 Chromatin - Histone protein / DNA complex in eukaryotic cells
Epigenetics
Definition : Heritable changes in gene activity and expression that occur without alteration in DNA sequence
Two well-known epigenetic modifications
- Chemical modification to the cytosine residues of DNA (DNA methylation)
- Histone modification
Why is it important ? >>> Epigenetic modifications regulate gene activity and expression during development and differentiation, or in response to environmental stimuli
Epigenetics is considered a bridge between genotype and phenotype
Explain how cells carrying identical DNA differentiate into different cell types >>> Epigenetics
Epigenome - global analyses of epigenetic markers across the entire genome
Chromatin - Histone protein / DNA complex in eukaryotic cells
Basic Unit - nucleosome - 146 bp of DNA wrapped around an octamer of the four core histones (H2A, H2B, H3 and H4)
- Euchromatin - transcriptionally active state - the region where DNA is accessible due to the relaxed state of nucleosome arrangement
- Heterochromatin - transcriptionally inactive state - the area where DNA is packed into highly condensed forms that are inaccessible to transcription factors
