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Gene Editing presentation on CRISPR-Cas9
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- 2. What is DNA? ●DNA stands for deoxyribonucleic acid ● It is found in the nucleus of every cell in your body ● Made up of billions of small units called ‘nucleotides’, DNA folds up to look like a twisted ladder. ● DNA is the genetic code that determines your phenotype
- 3. What is CRISPR-Cas9? ●CRISPR- Cas9 are protein complexes ● They act as immune systems in many bacteria ● Guide RNA identifies and locates the DNA sequence to be edited ● Cas9 cuts genomic sequence open with a double stranded break ● A gene is inserted, edited, or deleted
- 4. How do virusesinfect? ● Attachment – As virus enters body it will find the targeted cell by recognizing some special proteins called the receptors, and latch on to it. ● Entry – After the virus sticks to the receptor on the surface of the cell, it is brought inside the body of the cell ● Replication – the virus takes over the machinery of the cell to create its own copies of viral gene and viral proteins. ● Assembly – New virus particles are then formed using the materials created. ● Release – Once the new viral particles are assembled, they leave the cell to infect other cells, and this process usually kills the cell.
- 5. How could CRISPR-Casfight viruses? ● Interfere when viruses are copying themselves ● Prevent virus from attaching to cell
- 6. Should we useCRISPR-Cas technology? - What might be some benefits of using CRISPR? - Could be able to treat genetic diseases - Modify agricultural crops to be resistant against diseases - Are there ethical issues that arise that we need to consider? - Designer babies
- 7. Let’s look attwo case studies ● Researcher He Jiankui, edited embryonic cells and implanted them. ● These cells were designed to have a mutation to protect the embryos against HIV. ● Before, CRISPR-Cas9 had only been used in mature cells, one that would not go into the germ line meaning the traits were not heritable ● Took a controversial leap in using CRISPR-Cas9 to since it would forever alter the germline ● Received a transfusion of edited stem cells to treat her sickle cell anemia ● Cells harvested stem cells are edited using CRISPR-Cas9 ● Cells are infused back into the body after a round of chemotherapy. ● These cells do not affect the germ line
- 8. Questions to Consider - Whois being affected? - Does the situation outweigh the risks? - Who should have access to it? - Should parents have the right to choose genetic modifications for their future children? - Does that mean people with these traits living in today’s time less/more valuable in society? - Should gene editing be used for conditions that are not immediately life- threatening, like the risk of HIV? - Could He Jiankui's research lead to increased stigmatization or discrimination against people living with HIV? - What are the potential long-term societal implications of gene-editing technologies on socioeconomic inequality? - What are the potential risks or side effects associated with using CRISPR to treat sickle cell disease or HIV?
- 9. References Bradel17. (2020, May27). GCSE SCIENCE (BIOLOGY): What is DNA and how does it work? Retrieved October 08, 2020, from https://www.tes.com/en-us/teaching-resource/gcse-science-biology-what-is-dna-and-how-does-it-work-12319000 Cryanoski, D., Ledford, Heidi. (2018, November 29). International outcry over genome-edited baby clain. Nature. Retrieved October 08, 2020. Lewis, T. (2019, October 23). Scientists Program CRISPR to Fight Viruses in Human Cells. Retrieved October 07, 2020, from https://www.scientificamerican.com/article/scientists-program-crispr-to-fight-viruses-in-human-cells/ Lu, P. (2018, August 31). Better, Faster, Stronger, CRISPR: The Future of Gene-Editing and its Implications. Retrieved October 08, 2020, from https://www.equaljusticeproject.co.nz/articles/2018/08/better-faster-stronger-crispr-the-future-of-gene-editing-and-its-implications Plater, R. (2020, July 06). First Person Treated for Sickle Cell Disease with CRISPR Doing Well. Retrieved October 08, 2020, from https://www.healthline.com/health-news/first-person-treated-for-sickle-cell-disease-with-crispr-is-doing-well Plumer, B., Barclay, E., Belluz, J., & Irfan, U. (2018, July 23). A simple guide to CRISPR, one of the biggest science stories of the decade. Retrieved October 08, 2020, from https://www.vox.com/2018/7/23/17594864/crispr-cas9-gene-editing Virus. (n.d.). Retrieved October 07, 2020, from https://www.genome.gov/genetics-glossary/VirusWhat is a virus? (2020, October 03). Retrieved October 07, 2020, from https://www.mypathologyreport.ca/virus/ Xiao, Q., Guo, D., & Chen, S. (2019, March 22). Application of CRISPR/Cas9-Based Gene Editing in HIV-1/AIDS Therapy. Retrieved October 07, 2020, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6439341/
Editor's Notes
- #2 What is DNA? This very question puzzled scientists around the world for hundreds of years, until in the 1950s American biologist James Watson and English physicist Francis Crick discovered its true nature. DNA, formally known as deoxyribonucleic acid, carries all your genetic information, which can be thought of as the instructions that make you, you. The DNA molecule is made up of billions of subunits called nucleotides, which bind to one another giving DNA its twisted ladder appearance-more technically known as a double helix. Found in nearly every cell in the body, DNA is used to produce amino acids, which in turn create proteins, which can then form cells, leading to tissues, and organs and when they’re all put together and working, they make a living creature like you and me. DNA determines everything about you from the color of your hair and eyes, to your height, and just about everything in between. Essentially, DNA is like the blueprint of ourselves, from which every characteristic is determined.
- #3 Over the past decade CRISPR-Cas9 has become a very popular method of gene editing because its fast, cheap, accurate, and relatively easy to use. CRISPR-Cas is a protein complex that normally acts as an adaptive immune system in bacteria. The complex is composed of two parts: A guide RNA which locates and identifies a genomic sequence, and Cas9 which cuts a genomic sequence. Together, the CRISPR-Cas9 complex is normally used to combat viruses and invasive genetic elements that could harm the host bacteria. What interests scientists the most about this protein complex, however, is its ability to make precise edits to genes. Through extensive research and experiments it is now understood that CRISPR-Cas9 can be used to both delete targeted genes from a DNA sequence, as well as insert a gene into a targeted DNA sequence, making it an incredibly useful tool for a variety of reasons.
- #5 Some viruses produce DNA as an intermediate step in their replication process, and the DNA can be targeted and cut by CRISPR-Cas system For those who don't produce DNA, we can use Cas13, a special type of Cas protein that targets viral RNAs. CRISPR-Cas can target and edit receptors on the surface of the host cell, and prevent virus from attaching onto the receptors, which prevents infection One example is HIV virus, which needs to bind to receptors encoded by CCR5 gene.
- #7 Gi -an - coo - ee Define: Sickle Cell: disease where your blood cells don’t form correctly, unable to get nutrients to parts of your body Germline -- Genes that can be pass down from your parents, like eye colour. However having this mutation can only protect against some variations of HIV but not others CRISPR-Cas is not a perfect system so there is a chance it edited necessary portions of the DNA It has not been done before so there is a question of safety for the embryos and mother Cite: Article 1 from martin healthline.com/health-news/first-person-treated-for-sickle-cell-disease-with-crispr-is-doing-well