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CRISPR Can Now Be Used to Edit Individual Bases

posted by Fnord666 on Sunday November 05 2017, @10:47AM   
from the designer-genes dept.

MrPlow writes:

Submitted via IRC for takyon

CRISPR-Cas9 has been widely heralded as one of the most important scientific developments of recent years, thanks to its capacity to make edits to the human genome. Now, a more precise version of the tool has been developed by a team of scientists from the Massachusetts Institute of Technology and Harvard.

[...] Sometimes, only one base pair in a length of DNA is abnormal in some way – this is called a point mutation, and it accounts for 32,000 of the 50,000 changes in the human genome that have been associated with diseases. A study published in Nature looked at changing an A base into a G; w process that could address around half of those mutations.

[...] "Standard genome-editing methods, including the use of CRISPR-Cas9, make double-stranded breaks in DNA, which is especially useful when the goal is to insert or delete DNA bases," said David Liu, who led the research, speaking to the MIT Technology Review. "But when the goal is to simply fix a point mutation, base editing offers a more efficient and cleaner solution."

This project isn't necessarily a replacement for the CRISPR – it's a different tool that allows for a different kind of edit to be made. The results could have a profound impact on the effect that hereditary diseases can have on people's lives.

Source: https://futurism.com/crispr-can-now-be-used-to-edit-individual-bases/

Programmable base editing of A•T to G•C in genomic DNA without DNA cleavage (DOI: 10.1038/nature24644) (DX)

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Original Submission

• Re:bit twiddling the genome Re:bit twiddling the genome (Score: 5, Informative) by takyon on Sunday November 05 2017, @11:09AM (2 children)

  by takyon (881) <takyonNO@SPAMsoylentnews.org> on Sunday November 05 2017, @11:09AM (#592465) Journal

  It seems like the accuracy/precision is going up all the time.

  Nonviral CRISPR-Gold Editing Technique Fixes Duchenne Muscular Dystrophy Mutation in Mice [soylentnews.org]

  Optogenetics + CRISPR, Using Light to Control Genome Editing [addgene.org]

  The study described in the summary is another such advance:

  Extensive directed evolution and protein engineering resulted in seventh-generation ABEs (e.g., ABE7.10), that convert target A•T to G•C base pairs efficiently (~50% in human cells) with very high product purity (typically ≥ 99.9%) and very low rates of indels (typically ≤ 0.1%). ABEs introduce point mutations more efficiently and cleanly than a current Cas9 nuclease-based method, induce less off-target genome modification than Cas9, and can install disease-correcting or disease-suppressing mutations in human cells. Together with our previous base editors, ABEs advance genome editing by enabling the direct, programmable introduction of all four transition mutations without double-stranded DNA cleavage.

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• Re:bit twiddling the genome (Score: 0) by Anonymous Coward on Sunday November 05 2017, @11:21AM

  by Anonymous Coward on Sunday November 05 2017, @11:21AM (#592468)

  thanks for fishing out these related links. this is becoming really impressive.

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• Re:bit twiddling the genome (Score: 1, Disagree) by Anonymous Coward on Sunday November 05 2017, @01:24PM

  by Anonymous Coward on Sunday November 05 2017, @01:24PM (#592498)

  Id double check how they calculate those efficiencies if I were you. They like to play games with the denominator. Ie treat 1e6 cells, 99% of which die, then half of the remaining 10k cells are "edited" so it was 50% efficient. Also, in this paper we see they found some pre-edited cells (as is usual).

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