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Dr. Karl Dawson: The biologist's toolbox

March 2, 2018
Dr. Karl Dawson: The biologist's toolbox

"CRISPR is going to change the way we think about breeding processes, the way we think about changing the genetics of livestock, plants. Even microorganisms will be changed using this type of technology." — Dr. Karl Dawson on gene-editing.

The following is an edited transcript of Tom Martin’s interview with Dr. Karl Dawson, vice president and chief scientific officer at Alltech.

Tom:                            Dr. Karl Dawson is the vice president and chief scientific officer at Alltech and directs activities at the company’s bioscience centers around the world, including Alltech’s Center for Animal Nutrigenomics and Applied Animal Nutrition, where he is the co-director. We thank you for joining us.

Karl:                             Thank you.

Tom:                            The gene editing technology CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) allows researchers to quickly change the DNA of nearly any organism, including humans. Would it be fair to say that the implications are pretty enormous?

Karl:                             Yes. CRISPR is going to change the way we think about breeding processes, the way we think about changing the genetics of livestock, plants. Even microorganisms will be changed using this type of technology. In terms of the way it will move forward, it has ramifications for just about anything we think about in terms of the overall breeding process and the way we think about using genetics and the genetic material that’s in an animal, plant or other organism.

Tom:                            How does this differ from gene modification?

Karl:                             CRISPR could be considered a form of gene modification. It is different in that it is a very precise tool where we can go in and pick out very specific sites on this long DNA molecule and we can put things in or take things out of it. It is a form of editing or changing a gene structure. And it can be used to not only delete specific genes or pieces of DNA, it can also be used to add in pieces of DNA. So, we can make genetic modifications that way. The difference is that we don’t necessarily have to use a transgenic approach, which means we’re not taking material from other organisms and putting it into a new organism. We’re not changing or bringing two types of DNA together, if you’d like.

Tom:                            So, what are the implications for agriculture, for food?

Karl:                             For food, it is a very fast way of changing and, very specifically, changing specific genetic pieces or genetic information. If you take, for example, some of the things that are being done, one of the examples we look at is the polled cattle. Calves are very oftentimes dehorned when they’re young. Dairy cattle are dehorned. That is a process that is rather uncomfortable for the animal, and it’s something that is very difficult to do, but it is very important because it changes the safety of handling that livestock. There has been a CRISPR approach used to change that in livestock. With traditional breeding, you can cross a hornless animal — a polled animal — with a dairy cow and produce a hornless animal. But when you do that, the productivity of that dairy animal changes considerably because lots of other things change when you do that genetic cross.

                                    The idea of CRISPR is that we could actually go in and take the very specific gene that’s associated with that horn formation and eliminate that gene, or poll that gene. And when we do that, we are doing it almost immediately. The difference is, if I bred that animal or did that through traditional crossbreeding, it would probably take 25 years to produce a high-producing dairy cow with that polled characteristic. In this case, we can do it within calves immediately. No time changed. The next generation of animals will have that specific gene.

Tom:                            Wow. Pretty exciting, isn’t it?

Karl:                             That’s powerful stuff.

Tom:                            How does this technology impact the whole GMO debate?

Karl:                             It’s going to change the GMO debate a little bit. There’s still a lot of controversy in this area. Typically, if you look at CRISPR technology, there are a number of other of these. There’s one called TALEN (transcription activator-like effector nucleases) that’s out there and zinc-finger modifications or nucleases that do the same thing. But when you do this, you can go very specifically to a site in the DNA and make your changes. You’re not introducing any new DNA, so it is no longer a combination of DNA from two animals or transgenic. It is, in fact, just maintaining one type of DNA. As a result, it’s not necessarily a traceable activity. So, theoretically, you could actually do a CRISPR transformation of a particular gene and you would not know that it was any different than a natural mutation process. The only thing is that you directed that very specifically to a very specific gene and a very specific chromosome in that animal.

Tom:                            Getting genetically modified crops approved for use is complex and expensive, and most of the crops that have been modified are large commodity crops: corn, soybeans. Could the ease and low cost make genome editing a viable option for smaller specialty crops as well as animals?

Karl:                             I think it could. There’s going to still be an economic barrier there, I’m sure, whether you could do it economically, but it is a very rapid way. This type of technology is not that complex. In one presentation I heard the other day about this, they were talking about this being something some people could do in their basements one day. So, it’s not that complex to take over. So, yes, it may in the long run be a technique that is used to do that very rapidly in smaller crops, different organisms, even fungi and things like that that we use for food manufacturing.

Tom:                            The implications of the science are pretty profound. Even possibly a little scary. What about worries that the field’s breakneck pace is leaving little time to talk about ethical and safety concerns?

Karl:                             Just about every time you talk about CRISPR, that type of information comes up or that kind of discussion comes up. I guess it is a little bit scary if you think about some of the potentials of these things. One of the areas that we’ll talk a little bit about tomorrow in our gene editing presentation relative to mosquito control is that we have gene editing capability right now that will develop what’s called a “gene drive.” A gene drive will actually make it so a specific gene is always transmitted to the offspring. So, if you think about the possibilities there of transmitting a lethal gene to a mosquito, it’s possible to actually cause the extinction of that species. That is not a long time off, either. You could actually do that very easily and change the ecology of the system completely. It’s nice that we want to get rid of mosquitos and we don’t have to swat them anymore, but the activity here says, yes, you could do that, but what happens to the rest of the ecology if that happens?

Tom:                            Let’s take this opportunity to turn to your work on the Zika virus, if we could. If you can bring us up to date where you are.

Karl:                             This is more of an insect-control concept that we’re working on right now. Quite frankly, the Zika virus in our case is used as an example of what might be done in insect control. Our goal is really to look more at some of the other insects — for example, fly problems in the livestock industry. They face flies, and horn flies, and things like that. But the Zika virus gives us an opportunity to see what can happen with the mosquito population. It is probably more developed in terms of population control than any other insect population. Zika has allowed us to put a lot of emphasis on that today. So, there are a number of techniques that are being used to control mosquitos using both molecular tools such as gene editing as well as particular bacterial control systems that will help eliminate the carrier or vectors for these diseases.

Tom:                            And does that steer us away from chemicals?

Karl:                             Absolutely. One of our big limitations is the development of resistance to pesticides. There are mosquitos today that are extremely resistant. It takes five, 10, 15 times more insecticide to kill the same mosquito that was killed 20 to 30 years ago. So, it is changing very dramatically. The idea here would be to move away to more natural control mechanisms or more sophisticated and more efficient control mechanisms.

Tom:                            What ag-tech trends are you watching these days? Which ones really excite you?

Karl:                             One of the areas we talked about today was programmed nutrition and the idea of programming animals to get very specific responses, whether it’s an immune response or growth efficiency or better reproduction. One of the tools we have today is the use of appropriate nutrients at very specific times of an animal’s life. “Programming” young animals to be resistant to disease or “programming” animals to use a lot less minerals in their diets. Those are things that are very exciting because they’re changing the paradigm of what we used to think was common nutrition.

                                    We no longer just think about the diet composition or the nutrient composition of a diet. We start thinking about, “Well, how do we strategically use that nutrient component to change what the animal is doing throughout its life?” Those same concepts are being used to improve meat quality and product quality from livestock or even plant quality. We can use that nutritional approach to do those types of things. So, I think that’s one of the most exciting things that we’ve worked on recently.

                                    Technology is moving so fast in the agricultural field today. I’ve been at a loss to say I know what are going to be the best trends, but those things that have to do with nutrition are going to be very important to us in the future. I think gene editing, in some form or another, is going to be a very important area for us to think about in the future. It’s not going to be in the traditional ways we think about it. But if you think about the barriers, for example, right now, there is no genetically modified livestock that are being used in food production today; part of that is the fear of what recombinant DNA really looks like, but some of it is the lack of understanding of what some of those molecular changes are. There are cattle that have been developed in China recently. They’re totally resistant to tuberculosis. That was the result of a gene editing. The PRRS (Porcine Reproductive and Respiratory Syndrome) virus in pigs, we have genetically modified animals or used a CRISPR-type gene editing technology to make pigs resistant to the PRRS virus. So, those things are happening. Whether those will be accepted or not, that’s outside of my area of expertise, but the technology is there, and it’s going to change. So, we have to get ready for that type of technology.

Tom:                            I have to believe you must spend a lot of your time being fascinated.

Karl:                             Yes. There’s lots to do. Yes.

Tom:                            What’s the most interesting part of your work?

Karl:                             I’ve been doing this for quite a few years now, and I think the neatest thing that I have to do is — not the science space — but it’s the ability of the younger people we’re producing in science today to come up with innovative ideas. I was involved with the Alltech Young Scientist program here. The brilliance of these young minds, it just always blows me away, and it’s something I like to be involved with. Maybe it’s not a real basic science, but it’s that educational process that leads to innovation that I get excited about.

Tom:                            Dr. Karl Dawson, vice president and chief scientific officer at Alltech. We thank you so much.

Karl:                             Thank you.

Dr. Karl Dawson spoke at ONE: The Alltech Ideas Conference (ONE17). To hear more talks from the conference, sign up for the Alltech Idea Lab.

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