Cooking with CRISPR

 

A strip of DNA

                        A strip of DNA

CRISPR sounds like some clever kitchen trick we should all know about. In fact, CRISPR is a radical new approach to medical and scientific research, one that adds a new level of urgency to a familiar question in bioethics.

Does the fact that we can do something [insert the medical or biological procedure of your choice] mean that we should do it?

Debate continues over the use of now-familiar medical technologies such as birth control, ventilators, and artificial nutrition. A whole different level of debate is associated with genetic engineering … things like stem cell research, cloning, or in vitro fertilization, as well as genetically modified organisms (GMOs) in the food supply.

Do we really know the full implications of genetic engineering on the future of the human race?

What Does CRISPR Do?

These debates take on an added urgency with the emergence of CRISPR (I will not burden you with the scientific name, which would take up nearly a full line of type)—a new tool for genetic engineering. CRISPR has been likened to the search function of a word processor.  You decide what part of a gene you want to remove and/or replace, give CRISPR the appropriate instructions, and send it on its way. Voilá, the change is made.

Genetic work of the sort done by CRISPR has been around for nearly half a century … think of research into cystic fibrosis using mice or the development of pest-resistant corn. But before CRISPR, altering a gene was a laborious manual procedure. And once you had edited that gene, you had to breed and observe several generations of your subject (be it mice or corn) before you could tell if the experiment had worked as expected. Research on a single mutation could take as much as two years to determine success or failure.

According to a recent article in the New York Times, “altered genes frequently ended up in random locations, or in widely varying numbers” making it difficult to discern whether the concept was wrong … or whether it was a good idea that failed because of errors in the editing process. Progress was further slowed because you could only edit one gene one at a time; research on diseases thought to reflect the interaction of multiple genes (e.g., many forms of cancer) was halting at best.

20150508_075515_SJM-CRISPR-0510What makes CRISPR so significant is its speed, precision and breadth. Imagine a multi-pronged tool … a kind of biologic GPS that can accurately locate one or more genes in a segment of DNA … a pair of scissors to snip out the surrounding DNA … a tool to stitch up the DNA so it appears undisturbed. Because CRISPR can address multiple genes at the same time, projects that used to take months or years can now be done in a matter of days.

According to the New York Times, CRISPR is already being used to develop better bio­fuels and create new enzymes for things as diverse as laundry detergent and paper milling. Animal breeders produce superior lean-meat animals faster and more reliably than with crossbreeding. Dannon already deploys CRISPR to create strains of bacteria designed to produce more flavorful yogurt.

CRISPR’s Possibilities

Many scientists see great promise in CRISPR. It will facilitate targeted drug research … offer new insights into the role of genetics in mental illness … perhaps find a mechanism for eliminating mosquitos that carry Zika, dengue or Guillome-Barre.

It also offers the possibility of eliminating the BRCA gene for breast cancer … for ridding the world of Hodgkin’s lymphoma or AIDS. But scientists do not begin to understand the full significance of any specific genetic trait—or the consequences of changing it permanently. As a related article in the New Yorker notes the potentially devastating sickle cell anemia was an evolutionary protection against malaria. Would eliminating the gene for sickle cell lead to a dramatic increase in malarial deaths?

More broadly, what are the risks of modifying the genetic structure of embryos or “germ cells” that develop into eggs or sperm?  Such changes would be passed on to all subsequent generations.

This concern has also been with us for nearly half a century. What is new is that genetic engineering projects that once required well-funded laboratories run by universities or corporations are now potentially available to almost anyone with a good head for science and access to decent laboratory facilities for relatively brief periods of time.

Does the fact that we can have CRISPR mean that we should use it?

P.S. A curious sidelight of this discussion is that one of the most prominent researchers in the CRISPR world is a 34-year-old scientist named Feng Zhang, who grew up in Des Moines, my home for the last 15 years.

Comments

  1. Dennis Smith says:

    Fascinating–and frightening in a Brave New World sort of way. The acceleration of these technologies, both singly and jointly, threatens to elude our ability to control them. When will we realize that we’ve gone too far? (Have we gone too far already?) Thanks for the insight; now I’ll need to read the links.

    • Mary Gottschalk says:

      It is indeed both frightening and fascinating … it reminds of the old saw about computers … they don’t do anything differently that we used to do … they just do it faster. Good stuff and bad stuff!

  2. In our quest to fix every little “error,” will the unintended consequence be the elimination of creative genius? The problem with most of these technological miracles is that we don’t know we’ve traveled down a troublesome road until we’re past the point of no return. Thanks for another thought provoking post, Mary.

    • Mary Gottschalk says:

      Carol … the law of unintended consequences has lots of room to play here … it seems that with every passing day we are more and more reliant on the good motives of people running science and industry. Not always a comforting thought.

  3. Some synchronicity going on here! I just finished reading a fascinating article by human genome specialist Riccardo Sabatini, who gave a TedX talk in which he wheeled out on stage 175 huge books with 262,000 pages of information, each page filled with A, G, T and Cs, containing the entire DNA of colleague Craig Venter. Here’s the link: http://www.fastcoexist.com/3056735/a-few-drops-of-your-blood-can-tell-scientists-almost-exactly-what-you-look-like

    The bioethics is discussed only in passing with reference to a “dystopian world where police and criminals can easily profile our identities.” The goal Sabatini and his researchers are aiming for appears to be “making real the dream of personalized medicine.” I appreciate what you and Carol have alluded to: the horror of unintended consequences in pursuing such objectives.

  4. An interesting post, Mary. Thank you. My synchronicity was not nearly as thoughtful as Marian’s, but the X-Files episode last night was all about DNA. Of course, some of it was concerned with alien DNA. 🙂
    I can see “the law of unintended consequences,” but at the same time, I can see much good, as you discuss here. It’s also difficult for humans to turn away from the quest for knowledge. Perhaps that, too, is in our DNA.

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