University:
University of Virginia
Course:
BIOL 1040 | The DNA Revolution in Science and Society
Academic year:

2024
Views:

213

Pages:

2
Author:

Kayli N.

DNA Unit 2 Lecture 5 Germ plasma/Germ line: cells that form egg/sperm and continued into next generations ● Gametes to embryo, DNA produces offspring ● Ex. Mutation in egg/sperm and unites with egg/sperm, every proceeding will contain that mutation. Heterozygous may have half only have the mutation Soma: all other cells that don’t form egg/sperm, genetic info not moved next generation ● Somatic mutations: not in next generation ● Ex. None carry the mutation but after embryo is formed, the somatic mutation occurs. The cell grows and differentiates, the cells that have the mutation will proliferate and cause only that limb to have that mutation. If somatic mutation happens later in life, then it will have a less effect on the body ● Can have large or small effects depending on where they happen in development CRISPR (Jennifer Doudna): faster and accurate genome editing 1. Foreign DNA acquisition. Viral invaders stick genome into cells which incorporate DNA into CRISPR locus. Creates memory of infection in host cell 2. The CRISPR locus with the infection form RNA structures by transcription and processed to form structures with bacteria’s DNA 3. Combines with protein enzyme Cas-9. When new bacteria infect cell, the cell recognized/guides the bacteria’s DNA and cleaves it off invading viruses ● Engineered the guide RNAs into genome to cut any place in genome (cut and paste) ● Can be applied to other organisms and many uses Replaces previous approaches to gene manipulation that were inefficient ● Brown mouse, introduce black hair gene. Take stretch of DNA with gene of interest with markers and inject them into cultured cells. The “construct” finds its way into right place. If successful bound, take out the marker genes to screen them and see if it changed. Take the cells out into embryo but don’t know if it will be in soma or germline. Implant the embryo into foster mother to see if germline changes right Target Mutations: complications even if specific and create mosaics (not clean cut) ● When injected, must find its way through mosaic embryo to find the right place ● Cell is growing so if not quick, then it can become incorporated into wrong place ● Can generate off-target effects, insertions, or deletions Difficult to regulate method; easy and powerful, so easy to be misused in public ● Can buy CRISPR kits, biohacker misused by injecting CRISPR into himself New era of Eugenics: to improve qualities, forced sterilization of the unfit ● Ex. IVF is controversial cuz it is only choosing the best fit embryos CRISPR Modified Babies: He Jiankui 2018 altered embryos before implanting in mother for HIV resistant Lulu and Nana by deleting CCR-5 that codes for white blood cells ● ● ● ● ● HIV attaches to cell and interacts with CCR-5 for entry into cell He manipulated DNA by deleting CCR-5 so HIV couldn’t gain entry The father had HIV which is culturally discriminative in China Concerns abt “designer babies”, uncertain parent consent, improper oversight Negative feedback, bad look on Chinese science, but shows that there is potential for future medical advancements with this approach if needed (left the door open – Doudna), bioethics wrong due to violation and too early ● U.S. banned CRISPR editing this way by the FDA ● May cause more negatives than positives (unintended consequences/changes)