Eukaryotic gene regulation: Epigenetic factors
Chromatin structure: histones, methylation; euchromatin vs. heterochromatin. How does all this affect transcription?
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Heritable, but can be modified by environment… what does this mean?
Prader-Willi syndrome vs. Angelman syndrome: compare and contrast.
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1) histones are proteins that bind to the DNA and help to form a compact structure. Methylation either on the DNA or on the histones mask the negative charges on them (due to phosphate on the former and acidic r studies on the latter) causing their interaction to become more strong and compact. Now if a segment of DNA is tightly bound to the histones it will be difficult for it to unwind in order to facilitate transcription. Such a region is called heterochromatin. If a region of DNA is loosely interacting with the histones then it can be easily opened to allow transcription and is called as euchromatin.
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