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.
517
views
Ch. 17 - Transcriptional Regulation in Eukaryotes
Klug12th EditionConcepts of Genetics ISBN: 9780135564776
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - Introduction to Genetics17
- Ch. 2 - Mitosis and Meiosis36
- Ch. 3 - Mendelian Genetics51
- Ch. 4 - Extensions of Mendelian Genetics74
- Ch. 5 - Chromosome Mapping in Eukaryotes51
- Ch. 6 - Genetic Analysis and Mapping in Bacteria and Bacteriophages46
- Ch. 7 - Sex Determination and Sex Chromosomes33
- Ch. 8 - Chromosome Mutations: Variation in Number and Arrangement40
- Ch. 9 - Extranuclear Inheritance31
- Ch. 10 - DNA Structure and Analysis43
- Ch. 11 - DNA Replication and Recombination44
- Ch. 12 - DNA Organization in Chromosomes30
- Ch. 13 - The Genetic Code and Transcription54
- Ch. 14 - Translation and Proteins47
- Ch. 15 - Gene Mutation, DNA Repair, and Transposition41
- Ch. 16 - Regulation of Gene Expression in Bacteria29
- Ch. 17 - Transcriptional Regulation in Eukaryotes41
- Ch. 18 - Post-transcriptional Regulation in Eukaryotes33
- Ch. 19 - Epigenetics33
- Ch. 20 - Recombinant DNA Technology44
- Ch. 21 - Genomic Analysis36
- Ch. 22 - Applications of Genetic Engineering and Biotechnology36
- Ch. 23 - Developmental Genetics37
- Ch. 24 - Cancer Genetics34
- Ch. 25 - Quantitative Genetics and Multifactorial Traits54
- Ch. 26 - Population and Evolutionary Genetics45
Chapter 17, Problem 22d
Explain how the following mutations would affect transcription of the yeast GAL1 gene in the presence of galactose.
A deletion of one of the four UASG elements upstream from the GAL1 gene.
Verified step by step guidance1
Understand that the GAL1 gene in yeast is regulated by upstream activating sequences (UASG), which are binding sites for transcriptional activators that enhance transcription in the presence of galactose.
Recognize that the presence of multiple UASG elements (four in this case) allows for a stronger or more robust transcriptional activation due to cooperative binding of activators.
Consider that a deletion of one UASG element reduces the number of binding sites available for activators, potentially decreasing the overall transcriptional activation of the GAL1 gene.
Analyze how this reduction might affect the transcription rate: fewer activator binding sites can lead to lower recruitment of the transcriptional machinery, thus reducing mRNA synthesis from the GAL1 gene when galactose is present.
Conclude that while transcription will still occur in the presence of galactose (since other UASG elements remain), the efficiency or level of transcription is expected to be diminished compared to the wild-type gene with all four UASG elements intact.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Upstream Activating Sequences (UAS)
UAS elements are specific DNA sequences located upstream of a gene that serve as binding sites for transcriptional activators. In yeast, UASG elements enhance transcription of the GAL1 gene by recruiting activator proteins in response to galactose, increasing RNA polymerase II recruitment and gene expression.
Recommended video:
Guided course
08:41
Sequencing Difficulties
Transcriptional Regulation of the GAL1 Gene
The GAL1 gene is regulated by the presence of galactose, which activates transcription through binding of regulatory proteins to UASG sites. This regulation ensures GAL1 is expressed only when galactose is available, enabling yeast to metabolize this sugar efficiently.
Recommended video:
Guided course
09:22Review of Regulation
Effects of Deletions in Regulatory DNA Elements
Deleting one of the UASG elements reduces the number of activator binding sites, potentially decreasing transcriptional activation. This can lead to lower GAL1 expression levels in the presence of galactose, as fewer activators can bind and stimulate transcription.
Recommended video:
Guided course
03:38Maternal Effect
Related Practice
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.
436
views
Textbook Question
Explain how the following mutations would affect transcription of the yeast GAL1 gene in the presence of galactose.
A mutation within the GAL80 gene that blocks the ability of Gal80 protein to interact with Gal3p.
728
views
Textbook Question
Explain how the following mutations would affect transcription of the yeast GAL1 gene in the presence of galactose.
A point mutation in the GAL1 core promoter that alters the sequence of the TATA box.
510
views
Textbook Question
The interphase nucleus is a highly structured organelle with chromosome territories, interchromatin compartments, and transcription factories. In cultured human cells, researchers have identified approximately 8000 transcription factories per cell, each containing an average of eight tightly associated RNAP II molecules actively transcribing RNA. If each RNAP II molecule is transcribing a different gene, how might such a transcription factory appear? Provide a simple diagram that shows eight different genes being transcribed in a transcription factory and include the promoters, structural genes, and nascent transcripts in your presentation.
506
views
Textbook Question
A particular type of anemia in humans, called β-thalassemia, results from a severe reduction or absence of the normal β-globin chain of hemoglobin. However, the γ-globin chain, normally only expressed during fetal development, can functionally substitute for β-globin. A variety of studies have explored the use of the nucleoside 5-azacytidine for the expression of γ-globin in adult patients with β-thalassemia.
How might 5-azacytidine lead to expression of γ-globin in adult patients?
471
views