AquAdvantage salmon

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Wild-type Atlantic salmon (Salmo salar).
Wild-type Atlantic salmon (Salmo salar)

AquAdvantage salmon is a genetically modified (GM) Atlantic salmon developed by AquaBounty Technologies in 1989. A growth hormone-regulating gene from Pacific Chinook salmon, with a promoter gene from ocean pout, were added to the Atlantic salmon's genes (Tillmann, 2016, Bondar 2010). These two genes enable the GM salmon to grow year-round instead of only during spring and summer.

GM salmon are a commercially competitive alternative to wild-caught salmon and to fish farming of unmodified salmon. The purpose of the modifications is to increase the speed at which the fish grows without affecting its ultimate size or other qualities. GM fish grows to market size in 16 to 18 months rather than three years.[1] The latter figure refers to fish-farmed Atlantic salmon whose growth rates had already been improved over wild fish as a result of traditional selective breeding practices.

Genetic modification[edit]

AquAdvantage salmon were developed in 1989 by the addition of a single copy of the opAFP-GHc2 construct, which consists of a promoter sequence from ocean pout directing production of a growth hormone protein using the coding sequence from Chinook salmon.[2]:vii, 8 The continuous expression of this transgene allows the fish to grow year-round instead of only during spring and summer.[3] The stability of the new DNA construct was tested, revealing no additional mutational effects during insertion other than the two desired genes.[4] These GM fish were back-crossed (a two generation breeding protocol that starts by generating a hybrid offspring between two inbred strains, one of them carrying the mutation of interest) to wild-type Atlantic salmon, and the genetically modified EO-1ɑ gene sequence was identical in the second through fourth generations, indicating that the insertion is stable.[4]

While wild Atlantic salmon (Salmo salar) have two sets of chromosomes, raised AquaAdvantage salmon have three sets (i.e. are triploid). Induction of triploidy by treatment of eggs renders the fish sterile, reducing the risk of interbreeding with wild-type fish if any of the genetically modified fish were introduced into the wild.[5]

Production[edit]

AquAdvantage built a 100-ton/year aquaculture facility in Panama.[6]

Concerns[edit]

Aquaculture that uses conventionally bred salmon, mostly Atlantic salmon, cultivates the fish in net pens. In North America, this occurs mostly in coastal waters off Washington, British Columbia, and Maine. However, the application for FDA approval of AquAdvantage salmon specified land-based tank cultivation with no ocean involvement.[7] To address the concern about biological containment, the FDA requires AquaBounty to take extra precautionary measures to ensure transgenic fish cannot get into wild fish population in the ocean (Fox 2015, Bruce 2017). AquaBounty altered the fish to be only female and only sterile, the latter by treating the eggs to create triploid genes (Fox 2010, Benfey 2016) rendering these females sterile. Male fish are created only for egg-producing service, and are kept in secure, land-based facilities in Canada. (Muir 1999).

AquAdvantage salmon eggs are treated with pressure, to create batches of fish eggs with three copies of each chromosome compared to two copies (diploid). Any batch that contains 5 percent or more diploid fish, is destroyed because these diploid fish are capable of reproducing.[5] (Animal Production FAO, 2018) there are serious ecological and economic implications occur when stock fish escape from ocean-pens into native fish species’ ecosystems (Mapes, 2018). The AquaBounty AquAdvantage triploid fish are also, higher quality meat because they do not divert energy to reproduction, as a diploid fish would, instead use the energy to grow after maturity (Benfey, 2016).

AquaBounty takes extra precautionary measures to ensure better security using physical containment to reduce even further any transgenic interbreed with wild Atlantic salmon (Jeffery L Fox, 2010). The AquaBounty transgenic Salmon are only allowed to be raised in two land-bases tanks at two sites in Canada and Panama (Tizard et al., 2016). The fact that AquaBounty fish eggs will be produced in a land-based fresh-water research facility on Prince Edward Island in Canada, makes the cases that these AquaBounty salmon, are still salmon, and salmon hatch and develop in freshwater then swim to salt water to spawn when they reach adulthood (B. Josson, N. Jonsson,1993) so if eggs were to escape this facility, they would be unable to survive in the high salinity water nearby.[5] These eggs are then shipped to a land-based aquaculture facility at high altitude in Panama near a river that drains into the Pacific Ocean.[5] the facility is thousands of miles (120 km)

away from the nearest Atlantic Salmon wild populations (Gallegos, 2017; Upton, Cowan, 2015). It is here, the eggs hatch and grow to market size (B. Josson, N. Jonsson,1993). Most of the water in the drainage river into the ocean is unsuitable for salmon to survive, and is constricted by dams that act as barriers.[5] It is extremely unlikely that one of the 1.2 percent diploid fish (Benfey, 2016), would successfully navigate the dam barriers and survive the lethal waters and reach the Pacific Ocean, thousands of miles away (Gallegos, 2017; Upton, Cowan, 2015).

Other concerns include the heath effects of consumers due to the potentially heightened allergenicity of the GE fish and the potential effects of the hormone levels in the fish (Jeffery L Fox, 2010). However, there are no newly introduced proteins, fats, or any component different from salmon that has not been engineered (Børresen, 2016). The FDA has upheld that people with allergies to Atlantic Salmon will likely be allergic to AquAdvantage Salmon due to the similar species properties, not because it is genetically engineered (FDA)[citation needed] and that AquAdvantage Salmon is as safe to eat as non-GE salmon because there are no significant food safety hazards associated with it (FDA, 2012)[citation needed]. Other human health concerns arise about the increase hormone content in the edible tissue of transgenic fish (Green, 2016), the growth hormone content in two groups- AquAdvantage salmon and non-GE control- are both below the lower limit of observed quantities, and there was no significant difference in the amount of amounts of estradiol, testosterone, 17- ketotestosterone, T3, and T4 between the two groups (Food and Drug Administration Center for Veterinary Medicine Veterinary Medicine Advisory Committee, 2010)[citation needed]. The AquAdvantage salmon showed statistical difference in the concentration of an insulin-like growth factor (IGF-1) (Food and Drug Administration Center for Veterinary Medicine Veterinary Medicine Advisory Committee, 2010)., yet the amount of (IGF-1) found in AquAdvantage salmon is similar to, or lower than, other amount found in other common animal products- cows treated with growth hormones milk, cows not treated with growth hormones milk, organic cow milk, beef and cattle blood per milliliter (Food and Drug Administration Center for Veterinary Medicine Veterinary Medicine Advisory Committee, 2010). An average adult male that consumes 81.7 g of animal protein intakes 200 ng of IGF-1 per mL of blood, consuming regular amounts of AquAdvantage salmon imposes no greater IGF-1 content than an average animal containing diet (Giovannucci, et.al., 2003). The only notable difference between transgenic Atlantic salmon and the wild type is therefore the growth rate, with GM salmon reaching market size in half the time as conventional salmon (Børresen, 2016; Hafsa, 2016; Waltz 2016).

Critics raised concerns about potential environmental impacts if these fish reached rivers or oceans. Modeled invasion scenarios in semi-natural environments suggest that GM salmon would out compete wild-type salmon.[8][9][10][11] However, William Muir, the researcher who developed the "Trojan gene" hypothesis frequently cited by critics of this salmon, has discounted this scenario, noting their "sin of omission" and describing it as an "urban myth".[12] His analysis indicates that "the data conclusively shows that there is no Trojan Gene effect as expected. The data in fact suggest that the transgene will be purged by natural selection. In other words the risk of harm here is low.”[12]

Survival in new habitats[edit]

Fish can learn to feed on new prey after leaving hatchery environments. These adaptations could pose a risk if GM salmon were to be released into the wild.[13]

The ability of GM salmon to grow faster does not necessarily mean they are preferentially preyed upon, and this leads to increased survival.[vague] In a competition scenario, such as a release of GM fish from a salmon farm into the wild, the GM salmon could initially out compete wild-type salmon for food.[citation needed] This success would allow the GM salmon's greater survival.[8][13]

Rate of growth[edit]

AquAdvantage salmon have the potential to feed more efficiently than wild-type salmon. This leads to an accelerated growth rate during their first year after hatching. These fish have the capability to grow 11 times faster than wild-type salmon. This characteristic allows GM salmon to mature more rapidly and gives them the ability to reproduce in less than two years (about 700 days).[14][8] However, studies suggest this accelerated maturity of GM salmon does not provide a reproduction advantage over wild-type.[14]

Smoltification[edit]

Smoltification is the process of salmon adapting from freshwater to marine water. GM salmon can potentially achieve smolt size in only one year. This could allow AquAdvantage fish to reach the ocean quicker. The ability to reach the ocean first could allow GM salmon to access more food with less competition from wild-type salmon.[9]

Allergenicity[edit]

Fish are one of the eight food types that the FDA is required by law to treat with special care, with regard to allergies.[2]:97 As part of the regulatory process, the FDA required data on whether changes occur in the kinds or levels of fish allergens (such as parvalbumin) in AquAdvantage. The FDA reviewed data from the company and concluded, "The allergenic potency of triploid ABT salmon was not significantly different from that of sponsor control diploid salmon."[2]:104

Swimming capabilities[edit]

AquAdvantage salmon lack in swimming capabilities compared to wild-type salmon.[14][9][10][15] AquAdvantage individuals consume more energy when swimming than wild-type salmon. This is most likely due to the type of muscle fibers. AquAdvantage fish's muscle fibers have a smaller diameter than wild-type salmon. Because the force a muscle generates is proportional to its diameter, the smaller muscle diameter of AquAdvantage salmon produces less force than the wild-type.[15]

Reproductive competition[edit]

Under simulated models, both precocial parr and anadromous GM male salmon lack reproductive success and have a reduced number of surviving offspring. GM salmon's lack of fertilization success can be attributed to nest fidelity, quivering frequency, and spawn participation.[9] Under simulated competition environments, 94% of siring occurred by wild-type salmon, while only 5.4% was attributed to GM salmon.[14] This advantage allows more than twice as many wild-type offspring to be produced.[14] Other characteristics that could cause wild-type males to be chosen more frequently could be the lack of growth of the kype, the hooked jaw of a male, and red coloration on anadromous males, which demonstrates sexual maturity to females.

Using in vitro analysis, GM salmon's ejaculate was much less concentrated and had a lower sperm count and decreased sperm velocity, all of which can decrease GM salmon's fertilization success.[14]

Solutions[edit]

AquaBounty addresses these concerns by producing only sterile female salmon by converting the eggs to having triploid sets of genes. Any egg batch with more than 5% diploid genes.[non sequitur] Additionally, the fish will be raised in land-based fish farms with no connection to rivers that lead to oceans.[1][5][16]

Government regulation[edit]

United States[edit]

In September 2010, an FDA advisory panel indicated that the fish is "highly unlikely to cause any significant effects on the environment" and that it is "as safe as food from conventional Atlantic salmon"[2][17] In October 2010, 39 lawmakers asked the FDA to reject the application. Other groups requested that the fish carry a label identifying its transgenic origin.[17] Concerns included alleged flaws in sterilization and isolation, and excessive antibiotic use.[18]

On 25 December 2012, the FDA published a draft environmental assessment for AquAdvantage salmon.[3] The FDA also published a preliminary Finding of No Significant Impact.[19] A 60-day period for the public to comment was to elapse before the FDA reviewed Aquadvantage salmon again, which was arbitrarily extended until May 2013.[20][21]

The Food and Drug Administration (FDA) approved AquaBounty Technologies' application to sell the AquAdvantage salmon to U.S. consumers on November 19, 2015.[22] However, a rider to a spending bill signed into law on December 18, 2015 by President Obama bans its import until the FDA mandates labels for the genetically modified product[23][24] The decision marks the first time a genetically modified animal has been approved to enter the United States food supply. The decision came nearly twenty years after the company first submitted data to the FDA, and after they had raised ten generations of the animals.[18] The announcement released by the FDA states: "AquAdvantage salmon is as safe to eat as any non-genetically engineered (GE) Atlantic salmon, and also as nutritious." [25][26] One month later, language was introduced into a proposed federal spending bill requiring consumer notification that the fish is genetically modified.[27] As of October, 2018, AquaAdvantage salmon is not being sold in the US and the import of the salmon eggs from Canada to be raised at an AquaAdvantage fish farm in Indiana is prohibited by FDA.[28]

Canada[edit]

On 25 November 2013, Environment Canada approved the product for salmon egg production for commercial purposes in Canada.[29] In May 2016, the Canadian Food Inspection Agency approved the sale of the GM fish.[30] In July 2017, AquaBounty Technologies said they had sold 4.5 tons of AquaAdvantage salmon fillets to customers in Canada.[31]

References[edit]

  1. ^ a b Blumenthal, Les (August 2, 2010). "Company says FDA is nearing decision on genetically engineered Atlantic salmon". The Washington Post. Retrieved 2 August 2010.
  2. ^ a b c d FDA 2010.
  3. ^ a b FDA & December 2012.
  4. ^ a b Yaskowiak, ES; Shears, MA; Agarwal-Mawal, A; Fletcher, GL (August 2006). "Characterization and multi-generational stability of the growth hormone transgene (EO-1alpha) responsible for enhanced growth rates in Atlantic Salmon". Transgenic Research. Springer. 15 (4): 465–480. doi:10.1007/s11248-006-0020-5. PMID 16906447.
  5. ^ a b c d e f Bodnar A (October 2010). "Risk Assessment and Mitigation of AquAdvantage Salmon" (PDF). ISB News Report.
  6. ^ "FDA Considers Genetically Engineered Salmon". 21 September 2010.
  7. ^ von Mogel, Karl Haro (24 April 2013). "Interview with Ron Stotish at BIO". biofortified.org.
  8. ^ a b c Sundström & Devlin 2010, pp. 447–460.
  9. ^ a b c d Moreau, Conway & Fleming 2011, pp. 736–748.
  10. ^ a b Hu, W; Zhu, Z (2010). "Integration mechanisms of transgenes and population fitness of GH transgenic fish". Science China Life Sciences. 53 (4): 401–408. doi:10.1007/s11427-010-0088-2. PMID 20596905.
  11. ^ Ahrens, RN; Devlin, RH (2010). "Standing genetic variation and compensatory evolution in transgenic organisms: A growth-enhanced salmon simulation". Transgenic Research. 20 (3): 583–597. doi:10.1007/s11248-010-9443-0. PMC 3090570. PMID 20878546.
  12. ^ a b Zajac, Andy (November 26, 2010). "Foes of GE salmon raise specter of 'Trojan gene' effect". Los Angeles Times.
  13. ^ a b Sundström et al. 2009, pp. 762–769.
  14. ^ a b c d e f Fitzpatrick et al. 2011, pp. 185–191.
  15. ^ a b Lee, CG; Devlin, RH; Farrell, AP (2003). "Swimming performance, oxygen consumption and excess post-exercise oxygen consumption in adult transgenic and ocean-ranched coho salmon". Journal of Fish Biology. 62 (4): 753–766. doi:10.1046/j.1095-8649.2003.00057.x.
  16. ^ Ron, Benny (November 23, 2010). "Genetically Engineered Salmon Eggs Designed to Grow on Land". Archived from the original on 26 December 2010.
  17. ^ a b Mundy, Alicia; Tomson, Bill (1 October 2010). "Industry Fights Altered Salmon". The Wall Street Journal. Retrieved 5 November 2016.
  18. ^ a b Naik, Gautam (September 21, 2010). "Gene-Altered Fish Closer to Approval". The Wall Street Journal.
  19. ^ FDA & May 2012.
  20. ^ Federal Register 2012.
  21. ^ Reardon, Sarah (28 December 2012). "Approval for gene-modified salmon spawns controversy". New Scientist. Retrieved 2 January 2013.
  22. ^ "FDA Has Determined That the AquAdvantage Salmon is as Safe to Eat as Non-GE Salmon". U.S. Food & Drug Administration. 2015-11-19. Archived from the original on 2015-11-19. Retrieved 2018-02-09.
  23. ^ Dennis, Brady (2016-01-29). "FDA bans imports of genetically engineered salmon — for now". Washington Post. Archived from the original on 2016-01-29. Retrieved 2016-04-09.
  24. ^ "FDA Import Alert 99-40 "GENETICALLY ENGINEERED (GE) SALMON"". FDA. 2016-01-29. Archived from the original on 2016-01-31.
  25. ^ "FDA Has Determined That the AquAdvantage Salmon is as Safe to Eat as Non-GE Salmon". FDA. 2015-11-19. Archived from the original on 2015-11-19.
  26. ^ Steenhuysen, Julie; Polansek, Tom (2015-11-19). "U.S. clears genetically modified salmon for human consumption". Reuters. Reuters. Archived from the original on 2015-12-08. Retrieved 2016-04-09.
  27. ^ Dennis, Brady (17 December 2015). "FDA must develop plan to label genetically engineered salmon, Congress says". The Washington Post. The Washington Post. Retrieved 6 April 2016.
  28. ^ Blank, C (2018-08-08). "AquaBounty sells GMO salmon as losses mount". Seafood Source. Archived from the original on 2018-12-04.
  29. ^ Goldenberg, Suzanne; correspondent, US environment (2013-11-25). "Canada approves production of GM salmon eggs on commercial scale". The Guardian. ISSN 0261-3077. Retrieved 2019-05-03.
  30. ^ "Canada Approves Sale of Genetically Modified Salmon". Democracy Now. 2016-05-20. Archived from the original on 2016-05-21.
  31. ^ Waltz, Emily (2017-08-07). "First Genetically Engineered Salmon Sold in Canada". Scientific American. Archived from the original on 2017-08-07.

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