Lecture, chapter 10 - Gene regulation in eukaryotes

Today we finished chapter 10, on gene regulation in eukaryotes.

We discussed the role of DNA looping and insulators in ensuring that enhancers have an effect only on associated genes.

Then we discussed how a cell deals with the fact that much of its DNA is found as heterochromatin, making it inaccessible for RNA polymerase, and how DNA must be turned into euchromatin to be able to be expressed... or how euchromatin can be turned into heterochromatin to turn genes off (histone acetylation/deacetylation, DNA methylation/demethylation).

We also introduced the concepts of gene silencing and genetic imprinting

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Lab 7b - Smal scale plasmid purification (pJet1.2 with GAPC gene insertLab 13 Small scale plasmid purification (pGLO plasmid)

Today we used the bacteria we transformed (and cloned) with the pGLO and pJet1.2 plasmids to perform small scale plasmid DNA purifications (minipreps) and isolate the plasmids.

Then we performed restriction enzyme digestions, RED, using the restriction enzymes Ec0RI and HindIII (see restriction map) for the pGLO plasmid, and BglII for the pJet1.2 plasmid.

The idea was to isolate the GFP gene in a fragment, in the case of pGLO, and to confirm the success of the ligation procedure in the case of pJet1.2.

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Lecture, chapter 9 - Gene regulation in prokaryotesLecture, chapter 10 - Gene regulation in eukaryotes

Today we finished chapter 9, on gene regulation in prokaryotes, and started chapter 10, on gene regulation in eukaryotes.

We discussed the ways in which a protein can be a promoter for some genes and at the same time a repressor for others, and the role an inducer may have in changing its tertiary structure.

We also compared the action of global vs. specific regulators and introduced the concept of regulon.

Finally, we discussed the anti-termination control mechanism for regulation of gene expression.

We talked about the reasons control of gene expression in eukaryotes is more complex than in prokaryotes (supercoiling, presence of a nuclear envelope, cell differentiation in multicellular ones, developmental reasons, etc.).

We describe how the transcription apparatus is assembled and the role the mediator complex plays in facilitating its interaction with specific transcription factors.

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