Daily Newsletter April 5, 2012
Today's Topic: Eukaryotic Gene Regulation
Yesterday, we looked at the Lac operon, a classic example of bacterial gene regulation. The majority of prokaryotic gene regulation is handled at the transcriptional level. As we move to eukaryotic cells, we find that there are other ways that genetic expression can be regulated.
- Epigenome: This occurs in both prokaryotes and eukaryotes. In eukaryotes, the epigenome is noted by chemical changes to DNA and histone molecules that result in changes to the chromatin strand. These changes can "lock down" genes, preventing even the recognition of the promoter.
- IMPORTANT: the epigenome does not represent mutations. Instead it is a reversible chemical alteration to chromatin structure.
- This chromatin alteration can be passed vertically to offspring.
- Changes to the epigenome occur due to chemical signals and environmental changes (they change the organisms adaptation range).
- Check out the movies embedded on the MOOC site. They give a good perspective on epigenetics.
- Transcriptional control: This is control of the promoter and operator, and is very similar to what was seen with the Lac operon.
- Post-Transcription regulation: If you don't add the 5' cap, then RNA can't leave the nucleus. If you don't add the 3' poly-A tail, RNA is digested. If you don't splice out the introns, you don't have a code. Prevention of post-transcriptional modification can play a role in gene expression.
Eukaryotic Gene Regulation
Tissue Specific Gene Regulation
Gene Regulation in Eukaryotes (advanced)
Eukaryotic Gene Expression Problem Set (advanced)
Daily Challenge: Eukaryotic Gene Expression
Pick one topic regarding eukaryotic gene regulation that you are interested in, and in your own words, discuss that form of eukaryotic regulation.
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