American College of California Cas9 Genome Editing Technologies Questionary

BIO Homework 8 – Lecture Question Set (Due Fri Nov 13. 10pm)

Lecture 21 (questions from the National Center For Case Study Teaching In Science).
Part I:

2. How is Cas9 able to bind to specific sequences of DNA? What does Cas9 do to the sequences it interacts with?
3. What advantage does the CRISPR-Cas9 system offer compared to previous genome editing technologies?

Part II:

3. (Version A) Conventional gene therapy, described as introducing a functional copy of an allele into an individual that lacks this allele, has been explored as a clinical approach for decades. However, conventional gene therapy is not useful in treating certain genetic conditions.
a. Given what you have learned about the dystrophin gene, why is conventional gene therapy difficult for treating DMD?
b. When the gene product of a dominant genetic disorder is harmful, why is conventional gene therapy not easily used to treat such disorders?
4. (Version A) There are potential technical challenges with genetic modification in general and with CRISPR-Cas9 specifically.
a. What challenges might there be in using genome editing to treat an individual diagnosed with DMD after birth?
b. The article also refers to “off-target effects.” Explain what you think is meant by this phrase, and why it might be a risk when using CRISPR-Cas9 clinically.

Part III:
DNA Repair:
4. How is HDR different and why would this be desirable?
Transcriptional Effects:
5. How is dCas9 different than wild-type Cas9? Explain how it is able to repress transcription.
6. How can dCas9 be further modified to promote transcription?

Part IV:

4. In your own words, use Figure 1A to describe how Nelson et al. used the CRISPR-Cas9 system to “correct” this mutation.

8. Given this data and other considerations raised in this case study, what might Nadia share with her aunt about the current strengths and/or limitations of using a CRISPR-Cas9 approach to treat DMD postnatally?

I will put the slides in after you accept the bid there are nine questions