Skip to main content
Ch. 17+18 - Transcriptional Regulation in Eukaryotes
Chapter 17, Problem 23

Much of what we know about gene interactions in development has been learned using nematodes, yeast, flies, and bacteria. This is due, in part, to the relative ease of genetic manipulation of these well-characterized genomes. However, of great interest are gene interactions involving complex diseases in humans. Wang and White [(2011). Nature Methods 8(4):341–346] describe work using RNAi to examine the interactive proteome in mammalian cells. They mention that knockdown inefficiencies and off-target effects of introduced RNAi species are areas that need particular improvement if the methodology is to be fruitful.

Comment on how 'knockdown inefficiencies' and 'off-target effects' would influence the interpretation of results.

Verified step by step guidance
1
Understand the concept of RNA interference (RNAi) and its role in gene silencing by degrading mRNA, preventing protein production.
Define 'knockdown inefficiencies' as the incomplete reduction of target gene expression, which can lead to residual protein activity and affect experimental outcomes.
Explain 'off-target effects' as the unintended silencing of non-target genes, which can introduce confounding variables and obscure the interpretation of results.
Discuss how knockdown inefficiencies might result in underestimating the role of a gene in a biological process due to incomplete silencing.
Consider how off-target effects could lead to false associations between gene knockdown and observed phenotypes, complicating the identification of true gene interactions.

Verified Solution

Video duration:
2m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Knockdown Inefficiencies

Knockdown inefficiencies refer to the incomplete reduction of target gene expression when using RNA interference (RNAi) techniques. This can lead to residual expression of the gene, which may obscure the true biological effects of the gene's silencing. Consequently, if the knockdown is not efficient, it can result in misleading interpretations of the gene's role in cellular processes or disease mechanisms.
Recommended video:
Guided course
11:59
Steps to DNA Replication

Off-Target Effects

Off-target effects occur when RNAi molecules unintentionally silence genes other than the intended target. This can lead to unintended phenotypic changes and complicate the analysis of gene interactions. Understanding and controlling for off-target effects is crucial, as they can confound results and lead to erroneous conclusions about the specific roles of genes in development or disease.
Recommended video:
Guided course
03:38
Maternal Effect

Interactive Proteome

The interactive proteome refers to the complete set of protein interactions within a cell, which can influence various biological processes. Studying the interactive proteome helps researchers understand how proteins collaborate in pathways and networks. In the context of RNAi studies, accurately interpreting changes in the interactive proteome is essential, as knockdown inefficiencies and off-target effects can alter the dynamics of these interactions, leading to misinterpretations of cellular functions.
Recommended video:
Related Practice
Textbook Question

Explain how the following mutations would affect transcription of the yeast GAL1 gene in the presence of galactose.

A deletion within the GAL4 gene that removes the region encoding amino acids 1 to 100.

231
views
Textbook Question

Explain how the following mutations would affect transcription of the yeast GAL1 gene in the presence of galactose.

A deletion of the entire GAL3 gene.

173
views
Textbook Question

Much of what we know about gene interactions in development has been learned using nematodes, yeast, flies, and bacteria. This is due, in part, to the relative ease of genetic manipulation of these well-characterized genomes. However, of great interest are gene interactions involving complex diseases in humans. Wang and White [(2011). Nature Methods 8(4):341–346] describe work using RNAi to examine the interactive proteome in mammalian cells. They mention that knockdown inefficiencies and off-target effects of introduced RNAi species are areas that need particular improvement if the methodology is to be fruitful.

How might one use RNAi to study developmental pathways?

257
views
Textbook Question

In this chapter, we discussed several specific cis-elements in mRNAs that regulate splicing, stability, decay, localization, and translation. However, it is likely that many other uncharacterized cis-elements exist. One way in which they may be characterized is through the use of a reporter gene such as the gene encoding the green fluorescent protein (GFP) from jellyfish. GFP emits green fluorescence when excited by blue light. Explain how one might be able to devise an assay to test for the effect of various cis-elements on posttranscriptional gene regulation using cells that transcribe a GFP mRNA with genetically inserted cis-elements.

277
views
Textbook Question

Regulation of the lac operon in E. coli (see Chapter 16) and regulation of the GAL system in yeast are analogous in that they both serve to adapt cells to growth on different carbon sources. However, the transcriptional changes are accomplished very differently. Consider the conceptual similarities and differences as you address the following.

Compare and contrast the roles of the lac operon inducer in bacteria and Gal3p in eukaryotes in the regulation of their respective systems.

316
views
Textbook Question

Regulation of the lac operon in E. coli (see Chapter 16) and regulation of the GAL system in yeast are analogous in that they both serve to adapt cells to growth on different carbon sources. However, the transcriptional changes are accomplished very differently. Consider the conceptual similarities and differences as you address the following.

Compare and contrast the cis-regulatory elements of the lac operon and GAL gene system.

367
views