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Science Technology

CRISPR Now Cuts and Splices Whole Chromosomes (sciencemag.org) 18

Researchers report they've adapted CRISPR and combined it with other tools to cut and splice large genome fragments with ease. The study, conducted by researchers at the Medical Research Council (MRC) Laboratory of Molecular Biology in Cambridge, U.K., has been published in this week's issue of Science. Science Magazine reports: The tried and true tools of genetic engineering simply can't handle long stretches of DNA. Restriction enzymes, the standard tool for cutting DNA, can snip chunks of genetic material and join the ends to form small circular segments that can be moved out of one cell and into another. (Stretches of linear DNA don't survive long before other enzymes, called endonucleases, destroy them.) But the circles can accommodate at most a couple of hundred thousand bases, and synthetic biologists often want to move large segments of chromosomes containing multiple genes, which can be millions of bases long or more. "You can't get very large pieces of DNA in and out of cells," says Jason Chin, a synthetic biologist at the Medical Research Council (MRC) Laboratory of Molecular Biology in Cambridge, U.K. What's more, those cutting and pasting tools can't be targeted precisely, and they leave unwanted DNA at the splicing sites -- the equivalent of genetic scars. The errors build up as more changes are made. Another problem is that traditional editing tools can't faithfully glue large segments together. These issues can be a deal-breaker when biologists want to make hundreds or thousands of changes to an organism's genome, says Chang Liu, a synthetic biologist at the University of California, Irvine.

Now, Chin and his MRC colleagues report they have solved these problems. First, the team adapted CRISPR to precisely excise long stretches of DNA without leaving scars. They then altered another well-known tool, an enzyme called lambda red recombinase, so it could glue the ends of the original chromosome -- minus the removed portion -- back together, as well as fuse the ends of the removed portion. Both circular strands of DNA are protected from endonucleases. The technique can create different circular chromosome pairs in other cells, and researchers can then swap chromosomes at will, eventually inserting whatever chunk they choose into the original genome. "Now, I can make a series of changes in one segment and then another and combine them together. That's a big deal," Liu says.

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CRISPR Now Cuts and Splices Whole Chromosomes

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  • Excellent! (Score:4, Funny)

    by thomst ( 1640045 ) on Friday August 30, 2019 @09:34PM (#59142972) Homepage

    Smithers! Resequence the hounds ... !

  • by Pollux ( 102520 ) <speter&tedata,net,eg> on Friday August 30, 2019 @09:57PM (#59143002) Journal

    I predict, in between 200-300 years, the human race will...

    1) CRISPR themselves into a "more perfect" species, where everyone limits their genetics to a very specific set of genes that are socially "most desirable", then...
    2) The human species, so limited in its genetic diversity, will then go the way of the Gros Michel banana, where one strain of a disease will find a biological exploit within the homogeneous genetic mashup of the human race.

    • More realistically, there will be three kinds of human: Domesticated, wild, and half-breeds. That last category will be the biggest, and most medically challenged, of our descendants. The trend towards lack of bio-diversity will be overcompensated for by the chaos that our fumbling will cause. Not just with humans, but with all life forms, viruses to ecosystems, we'll trample them with cleated boots before we learn to wear ballet slippers.
      I still have faith that life will prevail, but I have no idea what fo

      • by Empiric ( 675968 )

        If you don't have a reason that you're not a half-breed already, you're a half-breed.

        But even if you think you're going to die well before your scenario can come to fruition, you don't get off that easy.

    • by ChromeAeonuim ( 1026946 ) on Friday August 30, 2019 @11:07PM (#59143132)
      Human genetic diversity is already pretty low, which is often thought to be due to a near extinction event 70 thousand years ago that reduced the human population to just 10-30k individuals. I don't think any transhumanist tinkering is going to make that much worse. If anything, it would probably make things better. I somewhat doubt that widespread human genetic alteration would be occurring without some forethought put into it.
    • Sci-fi gloom n doom? No, I expect people to do shit like change their skin color in various patterns, effectively making dna tattoos and coloring their hair and stuff like that. Humans are far more vain than they are interested in species wide change. The rich will of course design smart babies that will all be psychotic but that's not much different than their natural upbringing in most cases already. Gattaca, here we come!
    • Everyone has a different idea of perfect. On top of that, regardless of what is done in individual countries, it is almost certain that on a worldwide basis we won't just be correcting what some have determined to be "defects". We will be adding many different ideas of "improvements". And it won't all be biological. I would put slim odds on the idea that no country will welcome a cyborg movement.

      In other words, diversity typically increases around the time of an evolutionary event. This evolutionary event w

  • by Anonymous Coward

    maybe modern medical science can figure out appendicitis soon?

  • Interesting (Score:4, Interesting)

    by Stoutlimb ( 143245 ) on Friday August 30, 2019 @10:14PM (#59143024)

    Now transgender people can even swap their chromosomes. I can't wait to see what happens when the furry community gets wind of this...

  • It even makes frankenpotatoes you can turn into julianne fries!

  • kills and eats !

    Are you horrified? Relieved? Hungry?

    Must be unpleasant having an incoherent metaphysics. I'll just call it Dawkinstein.

    • by Empiric ( 675968 )

      More literally illustrated than I intended. With another delimiter...

      {genetic sequence} kills and eats {genetic sequence}!

      Ah, that's clearer. Or less clear. Don't vanish, {genetic sequence}.

  • by nospam007 ( 722110 ) * on Saturday August 31, 2019 @03:49AM (#59143354)

    Lately all those articles actually for nerds and stuff that matters?

    New boss?

    I'm not complaining, just saying.

  • by AndyKron ( 937105 ) on Saturday August 31, 2019 @05:04AM (#59143398)
    For your listening enjoyment: CRISPR-Cas9 ("Mr. Sandman" Parody) | A Capella Science https://www.youtube.com/watch?... [youtube.com]
  • time to use it (Score:5, Interesting)

    by RhettLivingston ( 544140 ) on Saturday August 31, 2019 @11:43AM (#59144064) Journal
    There are some genetic issues that could be corrected with just a fraction of this technology. One is Myotonic Muscular Dystrophy. It is usually caused by a simple unstable repeated sequence in the DNA (CTGCTGCTG) that should never occur. With replication, the sequence gets longer, eventually disrupting nearby genes. Simply cutting out the unstable CTG sequences and joining the ends back together should be a cure. No insertions are needed. I'm hoping to see this as one of the earliest genetic faults to be wiped out entirely.

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