He Jiankui's Experiment: The Most Recent ConcernThe Birth of Genetically Edited twin BabiesTwo genetically edited babies, by the pseudonyms Lulu and Nana, were born last year, as a Chinese scientist, He Jiankui, announced at the Second International Summit on Human Genome Editing in Hong Kong, 2018. As a part of the research, He's team altered the twins DNA while they were embryos to become resistant to future HIV infection. The research has brought a conversation that catches the attention of all human beings in the world, including those without any expertise in such fields: what is the future of human gene editing technology?
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Three things you have to know
CRISPR-Cas9Learn about the genome editing tool He used in his experiment.
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The Somatic Cell Genome ModificationExplore one of the two genome editing applications and regulations about it.
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The Germline Cell Genome ModificationExplore one of the two genome editing applications and regulations about it.
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The Genome Editing Tool:CRISPR-Cas9Many prokaryotes have a similar immune mechanism as humans. We human's immune system helps us to acquire immunity to certain types of disease by vaccination. CRISPR-Cas does the similar thing to prokaryotes. CRISPR is like a blacklist and Cas is like a scissor that cuts fragments from pathogens' DNA at certain positions as their identities and adds them into “blacklist”. Cas9 is a type of Cas, which is the most suitable one for genome editing purpose. We use prokaryotes' immune mechanism as a tool to edit the genome of a cell, since it allows high precision editing and could prevent natural repairing when DNA is cut.
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The Somatic Cell Genome Modification |
The Germline Cell Genome Modification |
The somatic cell genome modification changes the genes in cells in the human body other than egg and sperm cells. This makes all changes unable to be passed to future generations.
This technology could help patients to correct genetic defects or treat genetic diseases if used in pluripotent and other stem cells and in early stages of human development. But just as other innovative technologies, risks cannot be avoided, including inaccurate editing and off-target effects, which could lead to unexpected gene mutations. |
The germline cell genome modification changes the genes in eggs, sperm, or very early embryos, which are able to pass to all of the children and even succeeding generations.
Although the technology could benefit humans ranging from avoidance of severe inherited diseases to ‘enhancement’ of human capabilities,we have to be highly cautious about the uncertain risks of it. The current international ethical boundaries set a 14-day time limit regarding the germline modification research, including human embryos cultured in vitro. |