Genetically Modified Fish (GMO) Catfish Example - Dr. Rex Dunham
Welcome back, everybody. We're here today with Dr. Rex Dunham, who's going to talk to us about fish genetics and all the advances made in catfish genetics. Dr. Donald's has been working in the area of genetics for over 45 years and has been working with collaborators around the world.
He specializes in a host of genetic techniques, including quantitative genetics, traditional selective breeding, molecular genetics and genomics hybridization, transgenic says gene editing, xeno, genesis and reproduction, mostly with catfish. He and his research have genetically transformed the catfish industry twice during his career, creating a better fish for our farmers. And with that, I'll turn it over to you. OK, thank you very much. It's a pleasure to be speaking to all of you today.
As you can see, our topic is catfish genetic enhancement, traditional and biota technological approaches for food production while protecting the environment will be primarily focusing on catfish. But to complete, the story will also be presenting a couple of examples with other fish and from other laboratories. Also, Dr. Cline reminded me to tell you that although this is focusing on catfish, all of these approaches can be used and most of all, not all, but most all aquatic organisms. So when we build a house, we have, we use more than one type of tool and the same thing with genetic enhancement? We have a variety, a whole suite of genetic enhancement tools at our disposal. Ellis Prather on the far left and Homer Swingle on the far right did the first catfish genetics research at Auburn University, and they didn't even realize it because at that time they were evaluating different species of catfish to see which one was best for aquaculture and species are indeed species because of genetic differences.
So when we evaluate different species, we're actually doing a genetic evaluation once we've identified the best species. The first step in a genetic improvement program is to identify the best performing domestic strains strains and families within strains effect the success of all genetic enhancement programs. Once we've finished that step, then we can begin a focused genetic enhancement program. We have long term options and short term programs. Selection for body weight has been very successful across many different species, Although this is a semi slow process, we can double body weight through about eight to ten generations of selection. by 2003 because of the research done at Auburn, either through direct releases or farmers.
Learning how to do their own selection and also the creation of some catfish companies. Based on our research, about 70% of the industry was using selectively bred channel catfish. When any genetic enhancement program, if we're trying to help the farmer or the industry, we have to be aware of any. You might say side effects that the program may have on other commercially important traits. In the case of selection, that's correlated responses to selection. And if we select the increased body weight, there are some positive benefits.
The fecundity increase, the carcass yield increases. Disease resistance is a little bit better, but unfortunately the tolerance of low oxygen decreases. But on the other hand, we can overcome that problem through mechanical aeration to make sure that there's adequate oxygen in the water.
This illustrates the increase in the kilos per hectare produced by catfish farmers in 2003 versus 1980. During this time period, they were able to increase production by three fold. So this is a positive impact on the environment and takes pressure off of natural resources. So we're producing three times of food on the same, the same footprint. Now this is due to farmer innovation.
We have to give them credit as well as increased farmer skill, but also due to impact from research. And so there's probably a significant credit here due to improve aeration techniques as well as. Improvement in genetics that corresponds with the increased use of selectively bred catfish. In 1974, Roger Yant and R.O. Smitherman
demonstrated that in commercial densities and ponds that channel female catfish crossed with blue catfish males had improved gross carcass yield and and some other traits. Over time, we learned that this particular hybrid has increased growth rate, lower feed conversion, improved disease resistance, better survival, better tolerance of low dissolved oxygen, higher harvestability, improved processing yield. And so overall, the phenotype and production overall value has greatly improved by making this single cross. About 20 years ago or more, there were field trials in Alabama that showed that under farm conditions, these hybrids grew produce twice as much as channel catfish and had much better feed conversion efficiency.
Nowadays, we have the advantage the advent of much more intensive catfish production, increased horsepower for aeration just a few farmers using in Pond Raceway and several farmers using split ponds. The hybrid is an essential component for these systems to work as they have much better survival under these conditions compared to the parent species. So when we consider this whole suite of traits that are improved, the U.S.
hybrid catfish is probably the best example of genetic improvement in aquaculture that there has ever been. Now we can have a fish with the best genes in the world, but we're not going to be able to impact the farmer unless we're able to produce adequate number of fingerlings for commercial scale use. So in 1966, John Giudice and the U.S. Fish and Wildlife Service already knew that this fish had aquaculture potential. But the reproductive isolating mechanisms between those two species prevented commercial scale aquaculture. So it was almost 30 years later that we finally had small scale production commercial production of hybrids, and this was based on common carp pituitary extract technology developed at Auburn, and there was only one farm Gold Kist that was trying this technology.
So for about an eight year period, we're fluctuating between 1,000,000 to 5 million. Hybrid Fry produced an industry, then about 2000. We developed a new technology based on LhRh and do spawning. And that, coupled with some other factors, allowed us to double and triple hybrid embryo production, allowing commercial scale application finally of this great hybrid.
Key components included bag spawning, better nutrition, better hatchery and fertilization techniques, and another key factor in 2005. Auburn partnered with Eagle Aquaculture to commercialize the hybrid technology, and that gave an example that convinced other farmers that they should. They should try this. Eagle was very organized, had a factory type assembly line to produce hybrid embryos.
So when you look at this graph about 2005, you see a huge jump in the production of hybrid embryos and since that time, a steady increase in hybrid embryo production based on our labs technology. Last year, they estimate that 350 million hybrid catfish fry were produced. So again, now we revisit this change in farmer efficiency. And in 2020, if we look at the production records, catfish farmers are producing eight and a half times more catfish per hectare than what they were in 1980. So they continue to improve.
You've got producing more and more food on a smaller footprint. Theoretically, that also is more efficient and makes a smaller carbon imprint takes pressure off of natural resources. So aquaculture actually becoming more and more environmentally friendly. And also, if you look at that curve, look at about 2005 and we start to see a steep incline that corresponds with the increased adoption of hybrid catfish.
So we have other factors, including the intensive systems that are working hand-in-hand with the hybrids to improve production. But we can do better. The strain of Channel and Blue parent has a strong effect on the production of the F1 embryos.
Here's an example where we compared AU-1 and AU-7 over 5-6 consecutive years and AU-1 always produced two to three times more hybrid fry. And that was, of course, that's due to the females. But unfortunately, all males aren't created equal either as well. So we have an impact due to the strain of blue used. Also, then we can take those strain differences and we can improve hybrid embryo production further by selection for females that are highly productive.
We can also continue to improve the performance of the hybrids in regards to growth, disease resistance, carcass yield. So different genetic types of hybrids are improved, but there are still differences there. So Strain a parent affects hybrid performance. Both of these hybrids here are improved compared to the parents, but using two different types of males and the one with the Rio Grande grows 40% faster than hybrids produced with the other strain of males. one thing we're working on now is using combining abilities, evaluating that to determine what's the best way to continue to make a better and better Channel Blue hybrid. In this example, the key is if you look at the pie diagram on the left, the blue shaded area is a general combining ability due to the dams or mothers, and on the the red shaded area is the combining ability due to the blue catfish sires or males.
And what this tells us is that if we select for faster growing channels and faster growing blues and then hybridized those that will also increase the hybrid growth rate, we have a little bit different result when we look at dress out percentage. In this case, on the left, you see that the green pie is the major genetic component. This is a specific combining ability.
What that means is what we have to do is evaluate different pairs or sets and select for pairs of fish that produce the better performing progeny. And that's how we would improve hybrid performance for this trait. For many years, when we write grants, we complain we're using a wild fish. We really need money so we can make a genetically superior growing fish. For most major aquaculture species, we can't spin that story anymore because if we take wild catfish, then we domesticated them.
Then we selected them, and then we used hybridization and other programs. Now, if we compare the production of the wild fish to what we have now, it's a ten to 20 fold difference. But we can continue to do better.
And of course, new aquaculture species have not gone through this story. We're trying to make the hybrid progeny as very laborious and tedious, so we're trying to look at things like Xenogenesis to make embryo production more efficient. Xenogenesis is a method of reproduction in which successive generations differ from each other. It's analogous to human surrogacy. In that case, we can have one woman carrying the embryo that has the genetic material from another mother. I mean, from a from another female.
So the baby is not genetically related to the birth mother at all. With Xenogenesis we have. So that's what we mean by successive generations are are different in the case of Xenogenesis. It's the same concept, but the host is carrying the gonads and the gametes from the donor. So to do that, we sterilize the host. Generally through triploidy. Triploids are sterile.
The gonad development is atrophied, the gametes are not viable. And then we isolate stem cells from the blue catfish in this example, and we introduce those to the sterilized host. And in this case, what we're trying to do, we have a xeno genetic channel, catfish male, everything about him to channel catfish, except for he produces blue catfish sperm.
Therefore, the channel catfish female on the left, she recognizes him as normal, mates, and the product is 100% hybrid hybrid embryos. So that would be an improvement on our current technique. We can transfer those stem cells at different life stages, blastula, fry, even subadult. But the data to date indicates it probably works better with Fry sometime shortly after hatching.
Now, the Japanese and others have produced xenogenic salmon that, when mated together, produced pure rainbow trout. And there are xenogenic zebrafish males that, depending upon the stem cells introduce, were able to produce sperm from silver Danio, Goldfish and even mud loach. So we did have success here on the left. These are hybrid fingerlings that were produced by mating. xenogenic channel catfish male with a channel catfish female.
So you have to channel catfish parents. But all the offspring are hybrids on the right to show that I'm not lying. Those are the control channel catfish, and you can see the morphological difference. Now the problem was we were having more and more success, but we weren't getting the fertility and the fecundity that would allow commercialization.
So we're trying to overcome that problem. You have to have high enough transformation, rate Colonization of the cells and proliferation. one aspect we've been looking at is the correct time and development that will give you the highest colonization and proliferation of those donor cells. This is actually a graph from xenogenic white catfish, but we have almost identical illustration with Channel Catfish so we can mark these cells with fluorescence. And then later, 45 to 90 days later measure the rate of proliferation of those cells. And what we see here is if we injected the stem cells anywhere from zero to twelve days after hatch.
When you examine these slides, you can see individual slides, flora cells, fluorescent or sometimes they stick together in clusters. So we're looking at the data two different ways. But in both cases, you can see between four and six days post hatch, we get the greatest number of stem cells that take hold and start growing, which theoretically will result in more fertile, more fedund xenogenic fish. There's a next step that we want to look at is molecular genetics. The latest technology revolves around SNP single nucleotide polymorphisms where we're looking at the genetic variation at each individual base.
This technology allows us to do what's called genome wide association studies, where we can find in the genome which chromosome chromosome areas have the primary genes for a certain trait. In this case, we're looking at resistance to Edwardsiella Ictaluri, and we see that the it appears that the main genes that affect this trait are on chromosome one, twelve and 15 of Channel Catfish. Similar experiment But for Columaris, we find there's a different set of genes that have the greatest importance for survival located on chromosome seven, twelve and 14. So the next step that we're working on is actually doing marker assisted selection and genomic selection where we select for these DNA markers and in some cases, not all cases that will actually allow you to make better and faster genetic improvement. We've done a lot of genetic engineering with fish, and it looks quite promising. The most common type of research is where in the past is where a growth hormone genes have been transferred with catfish.
We can increase growth 50% or maybe even double and triple growth rates with this technique with a wide variety of fish, you know , 20%. But in some cases, as much as ten to 30 fold increase in growth has been accomplished. But of course, the latter is not a very common result.
In the case of catfish and salmon, that growth hormone increased growth hormone affects muscle structure. So these fish have increased the number of muscle fibers glycogen globules from mitochondria, but a reduced number of fat globules. Just like selection, we have to be aware of what other traits are affected when our goal is to transform one trait.
In this case, you can have pleiotropic effects where one gene affects more than one trait and the growth hormone channel catfish have better survival at cold temperatures. Growth hormone has a role in osmoregulation. The transgenic catfish also have better resistance to high salinity.
Another promising area is the transfer of anti-microbial peptide genes. If we transfer when we transferred cecropin to channel catfish, we're able to increase bacterial disease resistance, in some cases two to four fold. Recently, we have looked at we took different types of anti microbial peptides and compared them in vitro cecropin catalysts, side and pleurocidin and plurocydin antibiotics. And the most promising one was alligator cathlocidin.
We've been able to produce transgenic fish with the Cathelicidin gene, and in this case, this data comes from a challenge with where were they're being challenged with columnaris and the Cathelcidin and transgenic have four to 4.5 times greater survival than the non transgenic controls. So of this, these techniques can increase production efficiency and profits. These days, we're always talking about animal welfare, but are we really serious about it? So this is a technique where we can make healthier, fitter animals that have better animal welfare for aquaculture. But as you know, we're slow to accept it in society.
So by definition, genetically modified organisms are not organic, but if they reduce or. Eliminate chemical use and antibiotic use. Is that not beneficial is what we call truly organic things to think about. Now the goals of consumers can be are different often than producers. Rather than production
consumers are interested in a healthier, more nutritious and tastier food. So one thing we're examining is omega three fatty acid levels. And as as you know, omega three fatty acids have many important human a long list of human health benefits.
Catfish freshwater catfish have very low levels of omega three fatty acids compared to salmon, anchovy and tuna. So we've been transferring the saturation elongse gene in an attempt to increase omega three fatty acids in channel catfish. And we've had success. We want to do better and continue to research in that area. We've been able to increase the omega three fatty acid level 30 to 100%. Another important aspect of this is the ratio of the omega fatty acids that you consume also have health effects.
So this also alters the omega three to omega six ratio in a in an improved manner. The more healthy manner. We're not doing this type of research.
But another interesting example that Canadians transferred the antifreeze protein gene from winter flounder into Atlantic salmon in the Arctic and the Antarctic. The water is actually below zero C because of the salt. Therefore, the blood fish would die in those environments. But as you know, there are species that survive there. And that's because of the antifreeze protein genes that Canadians goals.
I consider risky transgenic research because in this case, what their goal was was to make a salmon that could be cultured closer to the Arctic Circle. By doing that, you're expanding the geographic range and essentially making it an exotic species. And if we're worried about environmental risk, exotic species are probably the most risky example in the fish world that we have. But they were able to produce salmon that made this antifreeze protein, but it didn't affect cold tolerance.
They also experimented with goldfish. It also did not lower the lethal temperature they could survive, but it did increase their survival at the low end of their their natural temperature tolerance. 20 years ago, the first commercialization of transgenic fish is ornamental zebrafish. And since that time, several other species. In this case, fluorescent protein genes from jellyfish were transferred.
And you create these new colors and black light at night you have neon fish swimming around, glowing in your aquarium. So I'm not. Excuse me. The latest development as gene editing where we have targeted genetic mutation, so we're trying to disable genes instead of inserting genes. And we have CRISPR technology in others that allows us to take scissors to DNA and delete and disable these genes. Myostatin is a muscle regulating protein that prevents us from continuing to grow and grow and grow during mammals lifetime and also slows down the growth of fish.
There are natural mutations of this gene where it doesn't function properly or at all leading to. And these mutations have been found in cattle and dogs where you have this double muscling Arnold Schwarzenegger phenomenon. And there's actually been a handful of humans that have mutated and the myostatin was disabled. So the goal here is, well, what happens if we delete the or disable the myostatin gene from Channel Catfish, or we're going to end up with a meatier larger channel catfish? So our lab members have accomplished that. And during the first 30 days of growth, we obtain about a 30% increase in growth rate. And if you look at the two histology slides in the center, the one on the left is a control.
The one on the right is a myostatin mutant. And it's obvious to the naked eye that the myostatin mutant has about 30 to 40% more muscle fibers. We've developed F1 fish with this mutation. If you look at the yellow highlighted area, I pinch myself and wonder because the mutants at low density in ponds are growing three times faster than the controls. So we're repeating that with a higher density and growing onto to food fish. Another growth regulator that we're looking at is M C, four R, which has a role in fat metabolism as well as growth.
And we've learned and others have learned that it actually has a critical role in fish reproduction. So if we knock out this gene, the fish become become sterile and the data that we and one other lab has indicates this is it can actually be a major regulator in the HPG axis. Additionally, by knocking out this gene, about 50 to 70% increase in growth can be achieved, as well as 50% better feed conversion efficiency. And and this in in regards to growth, this mutation functions in a recessive manner.
If you look at the yellow highlighted area again, the homozygous individuals. That group is the one growing the fastest. The second one down is a heterozygous, and they grow more no differently than the than the controls of a result that surprised us is the mc4r knockouts on left on the left. If you look at EPA, that omega three fatty acid by knocking out mc4r we double the EPA level, which if we insert the elongates gene from salmon, we get the same doubling of that fatty acid. If we look at DHA, we're by knocking out mc4r we get a significant increase. And but it's not quite as effective as knocking in the elongates.
So we have these excellent results for genetic engineering and gene editing, but are we going to impact aquaculture or are we going to impact food production? one concern is environmental risk. In order for there to be a risk, these fish would have to be more fit in regards to reproduction, foraging ability, predator avoidance, swimming ability in the natural environment. The data today strongly suggests that they are less fit and would likely be out competed in the wild. But with today's societal caution and attitude, that's not going to be enough in order to use these fish. We're going to have to control or confine these.
So how do we do that? And not only for transgenic mice, but other controversial genetic types used in aquaculture? So physical confinement, in my opinion, is not enough because we all learn from Jurassic Park that even though physically combine some idiot could steal the eggs and spread them, try to spread them throughout the world. So we want a technique where we have total reproductive control. Genetics is maybe the best route to accomplish that so that the fish can only mate when the hatchery manager intervenes. one approach is actually transgenic. In this case, what we're doing is inserting a gene, usually a short hairpin RNA AI gene that knocks out or prevents the expression of primordial germ cells, which are critical. They're the precursor for gametes.
So if you destroy those, the fish cannot produce eggs or sperm. This is obviously the top fish. This is normal sexual development of the channel catfish male. Bottom is obviously a female. Here we have some fish with the transgenic knockout females.
Either the ovaries do not exist or there's no other developing inside. Here are a couple males. one of them has no testes at all. And the other one greatly atrophied test testes. So we can't have a farm if all of our fish are sterile. So we have to be able to reverse that sterility in a sample of embryos so that we can grow some brood stock.
So these constructs, these transitions are designed so that we can add a compound to the hatching water that will turn that sterilizing gene off and allow normal development and the top fish. In this case, we're using a gene that we can turn off with application of copper sulfate. So the top fish is a transgenic fish hatched without copper sulfate, low levels, and the bottom fish is a transgenic fish with a sterilizing gene. But that gene's been disabled by hatching and copper, and we see the fantastic ovarian development. one problem, though, these transgenic fish without gonads, apparently they're important for growth. So we saw a 25% decrease in growth in survival.
This may have been due to the fact that they were in head to head competition with more aggressive controls. And we have preliminary data that indicates we might be able to correct this problem through selection. Another option is gene editing again, but in this case, targeting reproductive genes, followed by hormone therapy to restore fertility. Again, we use CRISPR technology to target and mutate those reproductive genes, such as LH, FSH and gene RH.
So then we can take normal spawning hormones like a HCG and LHRH and spawn a fish. They can only reproduce through the intervention of the hatchery manager again. Some of these fish can produce can ovulate and sperm, but the gametes are not viable.
So on the left, we have eggs from a sterilized female and they were non-viable, so the fungus is attacking and destroying them on the right. We have a sister who's been on hormone spawn, and now the eggs are fertile and developing normally. Again, we need to be concerned that we're affecting other important commercial traits on the left. We have different 5G access knockouts and they are growing as depending upon the knock out, they're growing as well or better than controls for added redundancy and security.
We tried making some double, triple and quadruple knockouts. In this case, some of the fish actually are going slower at the same rate, or some triple knockouts are growing faster than the controls. Of course. So we can oh, we're very close to having total control of these fish. But the next major hurdle is public acceptance. The issues there are politics, government regulation, environmental risk, education and food safety.
So now there's different terms transgenic GMO, genetically engineered, bioengineered. And then, of course, gene edited. This technology can benefit the farmer, the processor and also the consumer.
But the controversy is, is it safe? So. The when we apply one concern as well, if I eat a growth hormone fish. Is it the same as taking steroids? Well, we apply insulin and growth hormone to correct medical defects. We do it by injection or nasal sprays instead of oral because the digestive process is going to destroy the DNA. Otherwise, if we ate a carrot or a pig, we'd become a pig man or a carrot man. And obviously that doesn't occur.
These major scientific organizations U.S. National Academy of Science, Royal Society of London. EFO, W.H.O. and even the European Food Safety Authority, which bans all genetically engineered food. All of these organizations have done analysis and concluded that in almost all cases transgenic, there's no logical reason why there would be a safety issue with transgenic meat. But there is one thing that we do need, we need to treat each, be responsible and treat these on a case by case basis.
The main safety, the consideration is allergenicity, so if we took a peanut corn or shrimp gene that produced a protein that was responsible for the allergic response and people who have that problem, then we could theoretically produce a transgenic food that would be a health risk for those particular people. Another hurdle we have to overcome is the anti-GMO movement, and this is a career. This is a job. If you go online, these organizations are soliciting donations even if they do not want the public to accept this technology. Some of them have 30 year careers. If the technology was approved and accepted, they no longer have a job.
Another problem we overcome is human nature is to be leery of radically new technologies. This is a painting from 1802 that's propaganda material used from the 1802 to anti vaccine society. Most of us would probably agree that vaccine technology has had a very positive effect on humanity. But the message they're sending here, we have a line of people from 220 years ago. They're getting taking vaccine and within minutes they start growing horns and they have cows growing out of different parts of their body.
And obviously, that's ridiculous. Even the automobile was met with resistance. There were laws or proposed laws when they first came out saying You needed to have someone walk in front of the car waving a red flag. Some places had two to four mile per hour speed limits.
There were laws proposed that said if you saw a horse coming, you didn't want to make the horse afraid, so you needed to hide the car, take it apart, wait til the horse passed, and then reassemble the car and continue your journey. Obviously, there's no reason to have cars if you have those laws. And but perhaps in retrospect, maybe we should have been more concerned about the automobile. In some cases, we have political agendas to overcome.
The Alaskan congressmen openly admit they're trying to protect their clientele, their antique aquaculture, and of course, therefore they're also anti-gmo because they're trying to eliminate the competition for the commercial Alaskan fishermen. But a huge obstacle we're all involved in is public education. The. The vast majority of people really don't understand where their food comes from. They don't understand biology, and they have even more trouble with genetics. The two ladies on the right are two of my daughters. The one on the far right is Amy when I wrote my first book.
She was 16. I gave a copy of the book to all my children about two months later. I asked her what she thought about it now. She ended her education with an associate's degree and she was a. She was a straight-A student her entire academic career.
So she's an intelligent, educated person. She also has a very wry sense of humor and must have had a bad experience with freshman biology. She told me when I ask her if she how she liked my book, she said, Well, dad, I open the book. The first word that I saw was alleall So I closed the book. So this is the education that a large part of the public has been bombarded with through the years.
Another interesting example is the Jimmy Kimmel show had an episode where they interviewed West Coast grocery shoppers. They asked them what they thought about GMOs. And of course, they all said, Oh man, that's so horrible.
I would never eat such a thing. So then they ask him, Well, what is a GMO? Nobody could define what GMO stood for. Thomas Hoban and North Carolina did a very interesting study regarding genetically engineered food in 1994. Now he knew because of this propaganda.
He needed another way to evaluate the data, why people were answering the way they were. So he asked two additional questions. He asked them If you have ever. Have you ever eaten a hybrid fruit or vegetable? And 60% responded, no.
Then they asked, Is it ethical to eat a hybrid fruit or vegetable? About 60% of North Carolinians. And now this is. Rural. Basically, a rural state said no.
Of course, we have all eaten hybrid fruits and vegetables, that's quite common. He also did an international study, and he asked a true false question. Ordinary tomatoes do not contain genes while genetically modified ones do. If you just guess, 50% of the people could get it right. The Canadians were the only ones. That hit that 50% just by guessing United States was only 45%.
But Austria, France, Germany, Italy, 32 to 35% of the people could answer that question correctly. Obviously, they could have done better with a random gas or drawing marbles out of a hat. So we do have transgenic meat on the market now, the first one, as most of you are aware, our growth hormone transgenic fish aqua avantage produced by AquaBounty. So fish was the first one to reach the market, FDA approved these fish for consumption in 2015, but they were not marketed for several years because of labeling problems and laws that were activated to prevent their import. About the same time, the Canadians also approve them, and I don't have an exact figure, but approximately 20 metric tons or so have been sold in Canada. AquaBounty eventually got approval to grow these in the United States, and their first U.S.
grown transgenic salmon are on the market in the United States have been on the market, I believe, for a few months now. Now, in order for that to happen, the US had to enact labeling laws, the anti-GMO people are really upset with those laws because there's a variety of ways that you're able to label it. And this particular technique, instead of having a red label that says genetically engineered, it's a green label that says bioengineered.
And obviously, they disagree with that approach. So now we have gene editing, and some countries tightly regulate this new technology where we're instead of putting DNA and we're removing DNA, we're disabling DNA. So some countries have fairly lenient laws. Others very strict.
There's two lines of thought. Sometimes regulation is triggered by the process and sometimes by the product. In America, the first thing that triggers regulation is process. So, for example, you could have a fish with a natural mutation. And if you were to recreate.
That very same mutation, what gene editing and the two fish were identical, even though they are totally identical. The artificially produced one is going to be regulated. The other one is not because of the process. Gene edited fish have been commercialized for the first time.
AquaBounty again is there. It's probably myostatin. Edited Nile tilapia that are being marketed in Argentina.
They so we have a suite of genetic tools that we can use. My hypothesis prediction is in the future, all of our aquaculture organisms will be developed by multiple sets of genetic tools . So instead of having just selected fish or just triploid fish, you may have selected triploid hybrids, sex, reverse transgenic, et cetera.
To build the best, house will need to use as many tools as possible to address different traits. Thank you very much. It's not the end. It's only the beginning.