Question

Paper Reading Final (New Technologies review)

New Technologies - CRISPR gene editing Preview the document

Use the review article above Links to an external site.as a guide to the literature on the cutting edge technology of gene editing via CRISPRs.

1. Describe in 500 words where CRISPRs naturally occur.

2. Draw a figure to illustrate the BIOLOGY of CRISPRs

3. Describe in 500 words where the CRISPR technology is being used in medicine.

Use 2 examples to illustrate your point. Be sure to research US patents and out line the pros and cons of the clinical trials in progress. Use proper citations.

Answer 1

1.  CRISPR system first originated in bacteria and it acted as an immune system to protect bacteria from viruses. The scientists who discovered CRISPR had no way of knowing that they had discovered something so revolutionary. They didn't even understand what they had found. In 1987, Yoshizumi Ishino and colleagues at Osaka University in Japan published the sequence of a gene called iap belonging to the gut microbe E. coli.

Genome editing is a method that lets scientists change the DNA of many organisms, including plants, bacteria, and animals. Editing DNA can lead to changes in physical traits, like eye color, and disease risk. Scientists use different technologies to do this. Older gene-editing tools use proteins instead of RNA to target damaged genes. But it can take months to design a single, customized protein at a cost of more than$1,000. With CRISPR, scientists can create a short RNA template in just a few days using free software and a DNA starter kit that costs $65 plus shipping. CRISPR technology is a simple yet powerful tool for editing genomes. It allows researchers to easily alter DNA sequences and modify gene function. Its many potential applications include correcting genetic defects, treating and preventing the spread of diseases and improving crops. Genome editing can be used: For research: Genome editing can be used to change the DNA in cells or organisms to understand their biology and how they work. To treat disease: Genome editing has been used to modify human blood cells that are then put back into the body to treat conditions including leukemia and AIDS.

Cas9 enzymes together with CRISPR sequences form the basis of a technology known as CRISPR-Cas9 that can be used to edit genes within organisms. This editing process has a wide variety of applications including basic biological research, development of biotechnology products, and treatment of diseases. More specifically the Cas9 enzyme targets certain sections of the viral genome that prevents the virus from carrying out its normal function. Cas9 has also been used to disrupt the detrimental strand of DNA and RNA that cause diseases and mutated strands of DNA.

2. Schematic drawing illustrating examples of genome editing assays in plants. The CRISPR/Cas9 technology was successfully applied in model plants (Nicotiana benthamiana, Arabidopsis thaliana) and crops (rice, wheat). The Cas9 nuclease and the sgRNA matching the gene of interest are co-expressed using Agrobacterium tumefaciens as a vector in N. benthamiana leaves or transfected into protoplasts from Arabidopsis, wheat or rice. Then, the genomic DNA is extracted from the leaf tissues or protoplasts and subject to PCR-amplification with primers flanking the target site. The presence of Cas9/sgRNA-induced mutations can be easily detected using the restriction enzyme (RE) site loss method. The RE-resistant band can be cloned. The exact nature of the mutations is then revealed by sequencing individual clones.

3. Cas9 enzymes together with CRISPR sequences form the basis of a technology known as CRISPR-Cas9 that can be used to edit genes within organisms. This editing process has a wide variety of applications including basic biological research, development of biotechnology products, and treatment of diseases. More recently, this technology has been increasingly applied to the study or treatment of human diseases, including Barth syndrome effects on the heart, Duchenne muscular dystrophy, hemophilia, β-Thalassemia, and cystic fibrosis.

The CRISPR-Cas9 system works similarly in the lab. Researchers create a small piece of RNA with a short"guide" sequence that attaches (binds) to a specific target sequence of DNA in a genome. The RNA also binds to the Cas9 enzyme. Gene therapy carries the promise of cures for many diseases and for types of medical treatment that didn't seem possible until recently. With its potential to eliminate and prevent hereditary diseases such as cystic fibrosis and hemophilia and its use as a possible cure for heart disease, AIDS, and cancer, gene therapy is a potential medical miracle-worker.