13. Gene Regulation in Eukaryotes

Overview of Eukaryotic Gene Regulation

Open Question
What are processing bodies (P bodies), and what role do they play in mRNA regulation?
Open Question
Explain how the addition of acetyl groups to histones leads to a weaker association of DNA in nucleosomes.
Open Question
Compare and contrast promoters and enhancers with respect to their location (upstream versus downstream), orientation, and distance (in base pairs) relative to a gene they regulate.
Open Question
Distinguish between the cis-acting regulatory elements referred to as promoters and enhancers.
Open Question
Enhancers can influence the transcription of genes far away on the same chromosome. How are the effects of enhancers restricted so that they do not exert inappropriate transcriptional activation of non-target genes?
Open Question
What is one proposed role for lncRNAs?
Open Question
What are the sources of dsRNA? Diagram the mechanisms by which dsRNAs are produced and processed into small RNAs.
Open Question
How does dsRNA lead to posttranscriptonal gene silencing?
Open Question
Competing endogenous RNAs act as molecular 'sponges.' What does this mean, and what do they compete with?
Open Question
While circular RNAs were first described long ago, they have only recently been investigated for function. What are their known and suspected functions in the cell?
Open Question
The UG4 gene is expressed in stem tissue and leaf tissue of the plant Arabidopsis thaliana. To study mechanisms regulating UG4 expression, six small deletions of DNA sequence upstream of the gene-coding sequence are made. The locations of deletions and their effect on UG4 expression are shown here.Explain the differential effects of deletions B and F on expression in the two tissues.
Open Question
The UG4 gene is expressed in stem tissue and leaf tissue of the plant Arabidopsis thaliana. To study mechanisms regulating UG4 expression, six small deletions of DNA sequence upstream of the gene-coding sequence are made. The locations of deletions and their effect on UG4 expression are shown here.Why does deletion E lower expression of UG4 in leaf tissue but not in stem tissue?
Open Question
The UG4 gene is expressed in stem tissue and leaf tissue of the plant Arabidopsis thaliana. To study mechanisms regulating UG4 expression, six small deletions of DNA sequence upstream of the gene-coding sequence are made. The locations of deletions and their effect on UG4 expression are shown here.Why does deletion D raise UG4 expression in leaf tissue but not in stem tissue?
Open Question
How are mRNAs stored within the cell in a translationally inactive state, and how can their translation be stimulated?
Open Question
Diagram and explain how the inducibility of a gene—for instance in response to an environmental cue—could be mediated by an activator. Then show how it could be mediated by a repressor.