Question

Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis...

Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis pigmentosa often starts with decreased night vision and will progress to blindness as retinal cells die.

Several genes have been linked to Retinitis pigmentosa, one of which is GADD. Mice lacking GADD (these mice were experimentally created so that the GADD region of the genome was deleted) have increased expression of non-retinal genes in retinal cells. In other words, in these mutant mice, genes that are not normally expressed in the retina are expressed.  

Crx is a key retinal transcription factor. Crx binds regulatory elements called CBRs (Crx-binding regions). GADD has two CBRs, one immediately proximal to the transcription start site (TSS), and one a few hundred base pairs downstream of the TSS.

You have received DNA from three patients with Retinitis pigmentosa. From the DNA, you sequence the GADD gene and its proximal/core promoter region.   

None of the patients have mutations in the coding region of GADD. All of the mutations you find are in the CBRs. Your findings are below:

  • Patient 1 – Mutation in CBR1
  • Patient 2 – Mutation in CBR2
  • Patient 3 – Mutation in CBR1 and CBR2

Based on the phenotype of the mice lacking GADD, and what we’ve learned about gene expression what type of protein might GADD be? Explain your answer.

Homework Answers

Answer #1

Here, we learn about gene expression that expression of a gene is controlled by other genes called regulatory genes. Here, GADD is acting as regulatory gene for in expression of those genes which are not normally expressed. When GADD got deleted, its control on these genes was lost and hence, these genes started expressing. Hence, GADD is controlling the expression of these genes.

The protein formed by GADD is a suppressor protein because when GADD was expressed i.e. when GADD protein was being formed, the other genes (which are not expreesed normally)  were not expressed. It means GADD protien is supressing the expression of the gene which are not expressed normally.

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis...
Retinitis pigmentosa is a genetic disease that causes the breakdown and loss of retinal cells. Retinitis pigmentosa often starts with decreased night vision and will progress to blindness as retinal cells die. Several genes have been linked to Retinitis pigmentosa, one of which is GADD. Mice lacking GADD (these mice were experimentally created so that the GADD region of the genome was deleted) have increased expression of non-retinal genes in retinal cells. In other words, in these mutant mice, genes...
Remember: Crx is a key retinal transcription factor. Crx binds regulatory elements called CBRs (Crx-binding regions)....
Remember: Crx is a key retinal transcription factor. Crx binds regulatory elements called CBRs (Crx-binding regions). You use the DNA sequences from the patients to create plasmids for a luciferase assay. In a luciferase assay you add your promoter and any regulatory regions of interest to a vector containing the gene for luciferase. You then transform bacteria with the vector (you make bacteria take up the vector). The transcription of luciferase is controlled by the promoter/regulatory region you added to...
In Drosophila, loss-of-function Ultrabithorax mutations result in the posterior thoracic segments differentiating into body parts with...
In Drosophila, loss-of-function Ultrabithorax mutations result in the posterior thoracic segments differentiating into body parts with an identity normally found in the anterior thoracic segments. When the Ultrabithorax gene was cloned, it was shown to encode a transcription factor and to be expressed only in the posterior region of the thorax. Thus, Ultrabithorax acts to specify the identity of the posterior thoracic segments. Similar genes were soon discovered in other animals, including mice and men. You have found that mice...
Cells can become transformed (i.e., become capable of growing and dividing inappropriately, or become tumor cells)...
Cells can become transformed (i.e., become capable of growing and dividing inappropriately, or become tumor cells) because of mutations in genes such as proto-oncogenes and tumor suppressor genes. Protein P, normally stimulates apoptosis or cell death when activated. Consider a cell with a mutation in one allele such that protein P is always expressed and active, while the other allele of gene P is deleted. Which of the following is true for this cell? options Gene P is a proto-oncogene,...
Control of Gene Expression 1. How is it possible that individual cells of a multicellular organisms,...
Control of Gene Expression 1. How is it possible that individual cells of a multicellular organisms, which contain all the same DNA, can be so different from one another? 2. What are housekeeping proteins? What are their roles in the cell? 3. Describe the ways in which cells control gene expression. 4. How does control of transcription in prokaryotes and eukaryotes differ? 5. What is the role of operons in the prokaryotic genome? 6. A rare mutation occurs in bacteria...
QUESTION 44 Why does IPTG induce the lac operon? A. Its an analog of lactose B,...
QUESTION 44 Why does IPTG induce the lac operon? A. Its an analog of lactose B, It destroys lactose C. it increases the amount of lactose in the cell D. It reduces the concentration of cellular galactose QUESTION 46 For CRISPR-Cas to work on different genes, you have to alter the sequence of _____________ to provide specificity for where it cuts the DNA. A. single guide RNA B. the host gene C. Caspase domain D. protospacer adjacent motif QUESTION 48...
1). What were the justifications given for funding the Human Genome Project? A). Scientific discoveries B)....
1). What were the justifications given for funding the Human Genome Project? A). Scientific discoveries B). Facilitate technological advances C). Understanding and treating human diseases D). Economic impact E). All of the above. 2). What are some of the concerns with using transcriptional Fusion reporter gene constructs to following the expression of the gene of Interest? A ). The reporter gene fused to the gene of Interest may interfere with the proper folding and function of protein product of the...
5. A gene in the nuclear genome of an organism appears to be an ortholog of...
5. A gene in the nuclear genome of an organism appears to be an ortholog of a gene in the mitochondrial genome of another species. A friend argues that this is evidence against the endosymbiotic theory. Is this a valid argument? No, because during evolution of different taxa, transfer of genes between the nuclear and mitochondrial genomes is common, and different species have undergone transfer of different genes. No, because there is no way mitochondrial genes could end up in...
1. The lac operon responds to lactose and glucose. If wild-type E. coli cells are grown...
1. The lac operon responds to lactose and glucose. If wild-type E. coli cells are grown in media that contains both lactose and glucose, they will consume the glucose first because: (select all that apply) A.) the lac repressor remains bound to lacO, preventing the lac operon from being expressed at maximal levels B.) the permease (lacY) is not expressed in the presence of glucose, preventing lactose from entering the cell and being converted to allolactose, the inducer C.) the...
1) E. coli cells are growing in medium containing lactose but no glucose. Briefly describe the...
1) E. coli cells are growing in medium containing lactose but no glucose. Briefly describe the consequence of the following changes (one to two sentences for each condition): a. Addition of high concentration of glucose. b. A mutation that inactivates galactoside permease. c. A mutation that inactivates beta-galactosidase. d. A mutation that affects binding of CAP to c-AMP e. A mutation that affects binding of inducer to LacI f. A lac operator mutation that deletes all of the O1 2)...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT