Some mutations in the tra gene of Drosophila cause XX individuals to appear as males. In contrast, other mutations in tra cause XY flies to appear as females. Which of these phenotypes would you expect if a mutation in tra resulted in a null allele? Which would you expect if the mutation produced a constitutively active tra gene product? HINT: This problem involves an understanding of the Sxl regulatory pathway in Drosophila. The key to its solution is to review the functions of the normal TRA protein in Drosophila males and females.

Question

Want to see more full solutions like this?

Answer 1

Textbook Question

Chapter 18, Problem 1NST

Some mutations in the tra gene of Drosophila cause XX individuals to appear as males. In contrast, other mutations in tra cause XY flies to appear as females. Which of these phenotypes would you expect if a mutation in tra resulted in a null allele? Which would you expect if the mutation produced a constitutively active tra gene product?

HINT: This problem involves an understanding of the Sxl regulatory pathway in Drosophila. The key to its solution is to review the functions of the normal TRA protein in Drosophila males and females.

Expert Solution

Summary Introduction

To describe: The phenotype that would be expected if a mutation in tra gene results into null allele.

Introduction: The sex of Drosophila melanogaster is determined by the ratio of sex chromosomes to autosomes. The male Drosophila melanogaster is produced when the ratio of sex chromosomes to autosomes is 0.5. However, the female Drosophila melanogaster is produced when the ratio is 1.0.

Explanation of Solution

The tra gene is present in both male and female Drosophila melanogaster. The activity of tra gene is controlled by Sxl gene. In the absence of Sxl gene, the tra gene is spliced in a way that stop codon “UGA” remains present in the mature mRNA. This is observed in male Drosophila melanogaster as they lack the Sxl gene. The translation of mRNA with stop codon leads to the formation of a non-functional protein. However, in female Drosophila melanogaster, the Sxl gene promotes the removal of “UGA” from mRNA, and this forms a functional tra protein.

The mutation in the null allele leads to the formation of male Drosophila melanogaster. This is because the null gene has no effect on the Sxl gene. It does not activate the Sxl gene. The inactivated Sxl gene cannot remove the UGA gene from mRNA, and this leads to the formation of male Drosophila.

Conclusion

Thus, male Drosophila melanogaster would be expected if a mutation in the tra gene occurs in null allele.

Expert Solution

Summary Introduction

To determine: The phenotype that would be expected if mutation produces a constitutively active tra gene.

Introduction: The ratio of sex chromosomes to autosomes is termed as chromosomal ratio. The chromosomal ratio is analyzed by three genes. These are sex-lethal (Sxl), transformer (tra), and doublesex (dsx). The activity of tra gene plays a crucial role in determining the sex of Drosophila.

Explanation of Solution

The activity of tra gene depends upon the Sxl gene. The active tra gene indicates that there is Sxl gene. The tra gene in the presence of the Sxl gene is able to remove the stop codon “UGA” from the mRNA. It produces a function tra protein. The active tra protein is found in female Drosophila. However, the male Drosophila has inactive tra protein. This indicates that female Drosophila would be expected if the mutation produces a constitutively active tra gene.

Conclusion

Thus, the phenotype that would be expected if mutation produces a constitutively active tra gene is a female Drosophila melanogaster.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Students have asked these similar questions

Now read this abstract from a 2013 journal article What is the authors' explanation of how Gal80p works? Note UASG from the question above is the same as UASGAL The DNA-binding transcriptional activator Gal4 and its regulators Gal80 and Gal3 constitute a galactose-responsive switch for the GAL genes of Saccharomyces cerevisiae. Gal4 binds to GAL gene UASGAL. (upstream activation sequence in GAL gene pro- moter) sites as a dimer via its N-terminal domain and activates transcription via a C-terminal transcription activation domain (AD). In the absence of galactose, a Gal80 dimer binds to a dimer of Gal4, masking the Gal4AD. Galactose triggers Gal3-Gal80 interaction to rapidly initiate Gal4-mediated transcription activation. Just how Gal3 alters Gal80 to relieve Gals0 inhibition of Gal4 has been unknown, but previous analyses of Gal80 mutants suggested a possible competition between Gal3-Gal80 and Gal80 self-association interactions. Here we assayed Gal80-Gal80 interactions and tested for…

What would be the most likely effect of inhibiting the translation of hunchback mRNA throughout a Drosophila embryo?

You have been analyzing wing development mutants in Drosophila and have collected the genetic/Western data below. Your epistasis analysis (not shown), suggested your current model that DW-2 is upstream of WL-1. What is a plausible mechanism for how DW-2 regulates WL-1? mutant name wingless-1 doublewing-2 Prated with Ants-Wingless MW standards || | | mutanttype ODW-2 inhibits transcription of WL-1 O DW-2 polyubiquitinates WL-1 null null phenotype Model Ac O DW-2 phosphorylates WL-1 and prevents it from entering the nucleus O DW-2 cleaves WL-1 proteolytically Wings Mode of regulation DW-2 Wings Wings

Answer 2

Textbook Question

Chapter 18, Problem 1NST

Some mutations in the tra gene of Drosophila cause XX individuals to appear as males. In contrast, other mutations in tra cause XY flies to appear as females. Which of these phenotypes would you expect if a mutation in tra resulted in a null allele? Which would you expect if the mutation produced a constitutively active tra gene product?

HINT: This problem involves an understanding of the Sxl regulatory pathway in Drosophila. The key to its solution is to review the functions of the normal TRA protein in Drosophila males and females.

Expert Solution

Summary Introduction

To describe: The phenotype that would be expected if a mutation in tra gene results into null allele.

Introduction: The sex of Drosophila melanogaster is determined by the ratio of sex chromosomes to autosomes. The male Drosophila melanogaster is produced when the ratio of sex chromosomes to autosomes is 0.5. However, the female Drosophila melanogaster is produced when the ratio is 1.0.

Explanation of Solution

The tra gene is present in both male and female Drosophila melanogaster. The activity of tra gene is controlled by Sxl gene. In the absence of Sxl gene, the tra gene is spliced in a way that stop codon “UGA” remains present in the mature mRNA. This is observed in male Drosophila melanogaster as they lack the Sxl gene. The translation of mRNA with stop codon leads to the formation of a non-functional protein. However, in female Drosophila melanogaster, the Sxl gene promotes the removal of “UGA” from mRNA, and this forms a functional tra protein.

The mutation in the null allele leads to the formation of male Drosophila melanogaster. This is because the null gene has no effect on the Sxl gene. It does not activate the Sxl gene. The inactivated Sxl gene cannot remove the UGA gene from mRNA, and this leads to the formation of male Drosophila.

Conclusion

Thus, male Drosophila melanogaster would be expected if a mutation in the tra gene occurs in null allele.

Expert Solution

Summary Introduction

To determine: The phenotype that would be expected if mutation produces a constitutively active tra gene.

Introduction: The ratio of sex chromosomes to autosomes is termed as chromosomal ratio. The chromosomal ratio is analyzed by three genes. These are sex-lethal (Sxl), transformer (tra), and doublesex (dsx). The activity of tra gene plays a crucial role in determining the sex of Drosophila.

Explanation of Solution

The activity of tra gene depends upon the Sxl gene. The active tra gene indicates that there is Sxl gene. The tra gene in the presence of the Sxl gene is able to remove the stop codon “UGA” from the mRNA. It produces a function tra protein. The active tra protein is found in female Drosophila. However, the male Drosophila has inactive tra protein. This indicates that female Drosophila would be expected if the mutation produces a constitutively active tra gene.

Conclusion

Thus, the phenotype that would be expected if mutation produces a constitutively active tra gene is a female Drosophila melanogaster.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 3

Textbook Question

Chapter 18, Problem 1NST

Some mutations in the tra gene of Drosophila cause XX individuals to appear as males. In contrast, other mutations in tra cause XY flies to appear as females. Which of these phenotypes would you expect if a mutation in tra resulted in a null allele? Which would you expect if the mutation produced a constitutively active tra gene product?

HINT: This problem involves an understanding of the Sxl regulatory pathway in Drosophila. The key to its solution is to review the functions of the normal TRA protein in Drosophila males and females.

Expert Solution

Summary Introduction

To describe: The phenotype that would be expected if a mutation in tra gene results into null allele.

Introduction: The sex of Drosophila melanogaster is determined by the ratio of sex chromosomes to autosomes. The male Drosophila melanogaster is produced when the ratio of sex chromosomes to autosomes is 0.5. However, the female Drosophila melanogaster is produced when the ratio is 1.0.

Explanation of Solution

The tra gene is present in both male and female Drosophila melanogaster. The activity of tra gene is controlled by Sxl gene. In the absence of Sxl gene, the tra gene is spliced in a way that stop codon “UGA” remains present in the mature mRNA. This is observed in male Drosophila melanogaster as they lack the Sxl gene. The translation of mRNA with stop codon leads to the formation of a non-functional protein. However, in female Drosophila melanogaster, the Sxl gene promotes the removal of “UGA” from mRNA, and this forms a functional tra protein.

The mutation in the null allele leads to the formation of male Drosophila melanogaster. This is because the null gene has no effect on the Sxl gene. It does not activate the Sxl gene. The inactivated Sxl gene cannot remove the UGA gene from mRNA, and this leads to the formation of male Drosophila.

Conclusion

Thus, male Drosophila melanogaster would be expected if a mutation in the tra gene occurs in null allele.

Expert Solution

Summary Introduction

To determine: The phenotype that would be expected if mutation produces a constitutively active tra gene.

Introduction: The ratio of sex chromosomes to autosomes is termed as chromosomal ratio. The chromosomal ratio is analyzed by three genes. These are sex-lethal (Sxl), transformer (tra), and doublesex (dsx). The activity of tra gene plays a crucial role in determining the sex of Drosophila.

Explanation of Solution

The activity of tra gene depends upon the Sxl gene. The active tra gene indicates that there is Sxl gene. The tra gene in the presence of the Sxl gene is able to remove the stop codon “UGA” from the mRNA. It produces a function tra protein. The active tra protein is found in female Drosophila. However, the male Drosophila has inactive tra protein. This indicates that female Drosophila would be expected if the mutation produces a constitutively active tra gene.

Conclusion

Thus, the phenotype that would be expected if mutation produces a constitutively active tra gene is a female Drosophila melanogaster.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 4

Textbook Question

Chapter 18, Problem 1NST

Some mutations in the tra gene of Drosophila cause XX individuals to appear as males. In contrast, other mutations in tra cause XY flies to appear as females. Which of these phenotypes would you expect if a mutation in tra resulted in a null allele? Which would you expect if the mutation produced a constitutively active tra gene product?

HINT: This problem involves an understanding of the Sxl regulatory pathway in Drosophila. The key to its solution is to review the functions of the normal TRA protein in Drosophila males and females.

Expert Solution

Summary Introduction

To describe: The phenotype that would be expected if a mutation in tra gene results into null allele.

Introduction: The sex of Drosophila melanogaster is determined by the ratio of sex chromosomes to autosomes. The male Drosophila melanogaster is produced when the ratio of sex chromosomes to autosomes is 0.5. However, the female Drosophila melanogaster is produced when the ratio is 1.0.

Explanation of Solution

The tra gene is present in both male and female Drosophila melanogaster. The activity of tra gene is controlled by Sxl gene. In the absence of Sxl gene, the tra gene is spliced in a way that stop codon “UGA” remains present in the mature mRNA. This is observed in male Drosophila melanogaster as they lack the Sxl gene. The translation of mRNA with stop codon leads to the formation of a non-functional protein. However, in female Drosophila melanogaster, the Sxl gene promotes the removal of “UGA” from mRNA, and this forms a functional tra protein.

The mutation in the null allele leads to the formation of male Drosophila melanogaster. This is because the null gene has no effect on the Sxl gene. It does not activate the Sxl gene. The inactivated Sxl gene cannot remove the UGA gene from mRNA, and this leads to the formation of male Drosophila.

Conclusion

Thus, male Drosophila melanogaster would be expected if a mutation in the tra gene occurs in null allele.

Expert Solution

Summary Introduction

To determine: The phenotype that would be expected if mutation produces a constitutively active tra gene.

Introduction: The ratio of sex chromosomes to autosomes is termed as chromosomal ratio. The chromosomal ratio is analyzed by three genes. These are sex-lethal (Sxl), transformer (tra), and doublesex (dsx). The activity of tra gene plays a crucial role in determining the sex of Drosophila.

Explanation of Solution

The activity of tra gene depends upon the Sxl gene. The active tra gene indicates that there is Sxl gene. The tra gene in the presence of the Sxl gene is able to remove the stop codon “UGA” from the mRNA. It produces a function tra protein. The active tra protein is found in female Drosophila. However, the male Drosophila has inactive tra protein. This indicates that female Drosophila would be expected if the mutation produces a constitutively active tra gene.

Conclusion

Thus, the phenotype that would be expected if mutation produces a constitutively active tra gene is a female Drosophila melanogaster.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!

Answer 5

Textbook Question

Answer 6

Textbook Question

Answer 7

Expert Solution

Summary Introduction

To describe: The phenotype that would be expected if a mutation in tra gene results into null allele.

Introduction: The sex of Drosophila melanogaster is determined by the ratio of sex chromosomes to autosomes. The male Drosophila melanogaster is produced when the ratio of sex chromosomes to autosomes is 0.5. However, the female Drosophila melanogaster is produced when the ratio is 1.0.

Explanation of Solution

The tra gene is present in both male and female Drosophila melanogaster. The activity of tra gene is controlled by Sxl gene. In the absence of Sxl gene, the tra gene is spliced in a way that stop codon “UGA” remains present in the mature mRNA. This is observed in male Drosophila melanogaster as they lack the Sxl gene. The translation of mRNA with stop codon leads to the formation of a non-functional protein. However, in female Drosophila melanogaster, the Sxl gene promotes the removal of “UGA” from mRNA, and this forms a functional tra protein.

The mutation in the null allele leads to the formation of male Drosophila melanogaster. This is because the null gene has no effect on the Sxl gene. It does not activate the Sxl gene. The inactivated Sxl gene cannot remove the UGA gene from mRNA, and this leads to the formation of male Drosophila.

Conclusion

Thus, male Drosophila melanogaster would be expected if a mutation in the tra gene occurs in null allele.

Expert Solution

Summary Introduction

To determine: The phenotype that would be expected if mutation produces a constitutively active tra gene.

Introduction: The ratio of sex chromosomes to autosomes is termed as chromosomal ratio. The chromosomal ratio is analyzed by three genes. These are sex-lethal (Sxl), transformer (tra), and doublesex (dsx). The activity of tra gene plays a crucial role in determining the sex of Drosophila.

Explanation of Solution

The activity of tra gene depends upon the Sxl gene. The active tra gene indicates that there is Sxl gene. The tra gene in the presence of the Sxl gene is able to remove the stop codon “UGA” from the mRNA. It produces a function tra protein. The active tra protein is found in female Drosophila. However, the male Drosophila has inactive tra protein. This indicates that female Drosophila would be expected if the mutation produces a constitutively active tra gene.

Conclusion

Thus, the phenotype that would be expected if mutation produces a constitutively active tra gene is a female Drosophila melanogaster.

Answer 8

Expert Solution

Summary Introduction

To describe: The phenotype that would be expected if a mutation in tra gene results into null allele.

Introduction: The sex of Drosophila melanogaster is determined by the ratio of sex chromosomes to autosomes. The male Drosophila melanogaster is produced when the ratio of sex chromosomes to autosomes is 0.5. However, the female Drosophila melanogaster is produced when the ratio is 1.0.

Explanation of Solution

The tra gene is present in both male and female Drosophila melanogaster. The activity of tra gene is controlled by Sxl gene. In the absence of Sxl gene, the tra gene is spliced in a way that stop codon “UGA” remains present in the mature mRNA. This is observed in male Drosophila melanogaster as they lack the Sxl gene. The translation of mRNA with stop codon leads to the formation of a non-functional protein. However, in female Drosophila melanogaster, the Sxl gene promotes the removal of “UGA” from mRNA, and this forms a functional tra protein.

The mutation in the null allele leads to the formation of male Drosophila melanogaster. This is because the null gene has no effect on the Sxl gene. It does not activate the Sxl gene. The inactivated Sxl gene cannot remove the UGA gene from mRNA, and this leads to the formation of male Drosophila.

Conclusion

Thus, male Drosophila melanogaster would be expected if a mutation in the tra gene occurs in null allele.

Answer 9

Expert Solution

Answer 10

Expert Solution

Answer 11

Expert Solution

Answer 12

Summary Introduction

To describe: The phenotype that would be expected if a mutation in tra gene results into null allele.

Introduction: The sex of Drosophila melanogaster is determined by the ratio of sex chromosomes to autosomes. The male Drosophila melanogaster is produced when the ratio of sex chromosomes to autosomes is 0.5. However, the female Drosophila melanogaster is produced when the ratio is 1.0.

Answer 13

Explanation of Solution

The tra gene is present in both male and female Drosophila melanogaster. The activity of tra gene is controlled by Sxl gene. In the absence of Sxl gene, the tra gene is spliced in a way that stop codon “UGA” remains present in the mature mRNA. This is observed in male Drosophila melanogaster as they lack the Sxl gene. The translation of mRNA with stop codon leads to the formation of a non-functional protein. However, in female Drosophila melanogaster, the Sxl gene promotes the removal of “UGA” from mRNA, and this forms a functional tra protein.

The mutation in the null allele leads to the formation of male Drosophila melanogaster. This is because the null gene has no effect on the Sxl gene. It does not activate the Sxl gene. The inactivated Sxl gene cannot remove the UGA gene from mRNA, and this leads to the formation of male Drosophila.

Answer 14

Conclusion

Thus, male Drosophila melanogaster would be expected if a mutation in the tra gene occurs in null allele.

Answer 15

Expert Solution

Summary Introduction

To determine: The phenotype that would be expected if mutation produces a constitutively active tra gene.

Introduction: The ratio of sex chromosomes to autosomes is termed as chromosomal ratio. The chromosomal ratio is analyzed by three genes. These are sex-lethal (Sxl), transformer (tra), and doublesex (dsx). The activity of tra gene plays a crucial role in determining the sex of Drosophila.

Explanation of Solution

The activity of tra gene depends upon the Sxl gene. The active tra gene indicates that there is Sxl gene. The tra gene in the presence of the Sxl gene is able to remove the stop codon “UGA” from the mRNA. It produces a function tra protein. The active tra protein is found in female Drosophila. However, the male Drosophila has inactive tra protein. This indicates that female Drosophila would be expected if the mutation produces a constitutively active tra gene.

Conclusion

Thus, the phenotype that would be expected if mutation produces a constitutively active tra gene is a female Drosophila melanogaster.

Answer 16

Expert Solution

Answer 17

Expert Solution

Answer 18

Expert Solution

Answer 19

Summary Introduction

To determine: The phenotype that would be expected if mutation produces a constitutively active tra gene.

Introduction: The ratio of sex chromosomes to autosomes is termed as chromosomal ratio. The chromosomal ratio is analyzed by three genes. These are sex-lethal (Sxl), transformer (tra), and doublesex (dsx). The activity of tra gene plays a crucial role in determining the sex of Drosophila.

Answer 20

Explanation of Solution

The activity of tra gene depends upon the Sxl gene. The active tra gene indicates that there is Sxl gene. The tra gene in the presence of the Sxl gene is able to remove the stop codon “UGA” from the mRNA. It produces a function tra protein. The active tra protein is found in female Drosophila. However, the male Drosophila has inactive tra protein. This indicates that female Drosophila would be expected if the mutation produces a constitutively active tra gene.