Editing Genetically modified organism (section)

=== Insects ===
{{See also|Genetically modified insect}}
[[File:Genetic-Modifiers-of-MeCP2-Function-in-Drosophila-pgen.1000179.s006.ogv|thumb|[[Overexpression]] of [[MECP2|methyl-CpG–binding protein 2]] in ''[[Drosophila]]'' impairs climbing ability ('''right''') compared to the control group ('''left''').<ref>{{cite journal | vauthors = Cukier HN, Perez AM, Collins AL, Zhou Z, Zoghbi HY, Botas J | title = Genetic modifiers of MeCP2 function in Drosophila | journal = PLOS Genetics | volume = 4 | issue = 9 | pages = e1000179 | date = September 2008 | pmid = 18773074 | pmc = 2518867 | doi = 10.1371/journal.pgen.1000179 | doi-access = free }}</ref>]]
In biological research, transgenic fruit flies (''[[Drosophila melanogaster]]'') are [[model organism]]s used to study the effects of genetic changes on development.<ref>{{cite web|url=http://www.genome.gov/25520307|title=Online Education Kit: 1981–82: First Transgenic Mice and Fruit Flies|website=genome.gov}}</ref> Fruit flies are often preferred over other animals due to their short life cycle and low maintenance requirements. They also have a relatively simple genome compared to many [[vertebrates]], with typically only one copy of each gene, making [[Phenotype|phenotypic]] analysis easy.<ref>{{cite book | vauthors = Weasner BM, Zhu J, Kumar JP | chapter = FLPing Genes on and off in Drosophila | title = Site-Specific Recombinases | series = Methods in Molecular Biology | volume = 1642 | pages = 195–209 | date = 2017 | pmid = 28815502 | pmc = 5858584 | doi = 10.1007/978-1-4939-7169-5_13 | isbn = 978-1-4939-7167-1 }}</ref> ''Drosophila'' have been used to study genetics and inheritance, embryonic development, learning, behavior, and aging.<ref>{{cite journal |date=1 May 2011 |title=Drosophila – a versatile model in biology & medicine |journal=Materials Today |volume=14 |issue=5 |pages=190–195|doi=10.1016/S1369-7021(11)70113-4  | vauthors = Jennings BH |doi-access=free }}</ref> The discovery of [[Transposable element|transposons]], in particular the [[P element|p-element]], in ''Drosophila'' provided an early method to add transgenes to their genome, although this has been taken over by more modern gene-editing techniques.<ref>{{cite journal | vauthors = Ren X, Holsteens K, Li H, Sun J, Zhang Y, Liu LP, Liu Q, Ni JQ | title = Genome editing in Drosophila melanogaster: from basic genome engineering to the multipurpose CRISPR-Cas9 system | journal = Science China Life Sciences | volume = 60 | issue = 5 | pages = 476–489 | date = May 2017 | pmid = 28527116 | doi = 10.1007/s11427-017-9029-9 | s2cid = 255159948 }}</ref>

Due to their significance to human health, scientists are looking at ways to control mosquitoes through genetic engineering. Malaria-resistant mosquitoes have been developed in the laboratory by inserting a gene that reduces the development of the malaria parasite<ref>{{cite journal | vauthors = Corby-Harris V, Drexler A, Watkins de Jong L, Antonova Y, Pakpour N, Ziegler R, Ramberg F, Lewis EE, Brown JM, Luckhart S, Riehle MA | title = Activation of Akt signaling reduces the prevalence and intensity of malaria parasite infection and lifespan in Anopheles stephensi mosquitoes | journal = PLOS Pathogens | volume = 6 | issue = 7 | page = e1001003 | date = July 2010 | pmid = 20664791 | pmc = 2904800 | doi = 10.1371/journal.ppat.1001003 | veditors = Vernick KD | doi-access = free }}</ref> and then use [[homing endonuclease]]s to rapidly spread that gene throughout the male population (known as a [[gene drive]]).<ref>{{cite web | vauthors = Gallagher J | url = https://www.bbc.co.uk/news/health-13128327 | title = GM mosquitoes offer malaria hope | work = BBC News, Health | date = 20 April 2011 | access-date = 22 April 2011 }}</ref><ref>{{cite journal | vauthors = Windbichler N, Menichelli M, Papathanos PA, Thyme SB, Li H, Ulge UY, Hovde BT, Baker D, Monnat RJ, Burt A, Crisanti A | title = A synthetic homing endonuclease-based gene drive system in the human malaria mosquito | journal = Nature | volume = 473 | issue = 7346 | pages = 212–5 | date = May 2011 | pmid = 21508956 | pmc = 3093433 | doi = 10.1038/nature09937 | bibcode = 2011Natur.473..212W }}</ref> This approach has been taken further by using the gene drive to spread a lethal gene.<ref>{{cite journal | vauthors = Wise de Valdez MR, Nimmo D, Betz J, Gong HF, James AA, Alphey L, Black WC | title = Genetic elimination of dengue vector mosquitoes | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 108 | issue = 12 | pages = 4772–5 | date = March 2011 | pmid = 21383140 | pmc = 3064365 | doi = 10.1073/pnas.1019295108 | bibcode = 2011PNAS..108.4772W | doi-access = free }}</ref><ref name="Knapton">{{cite news| vauthors = Knapton S |title=Releasing millions of GM mosquitoes 'could solve zika crisis'|url=https://www.telegraph.co.uk/news/worldnews/zika/12143563/Releasing-millions-of-GM-mosquitoes-could-solve-zika-crisis.html|access-date=14 March 2016|newspaper=The Telegraph|date=6 February 2016}}</ref> In trials the populations of ''[[Aedes aegypti]]'' mosquitoes, the single most important carrier of dengue fever and Zika virus, were reduced by between 80% and by 90%.<ref>{{cite journal | vauthors = Harris AF, Nimmo D, McKemey AR, Kelly N, Scaife S, Donnelly CA, Beech C, Petrie WD, Alphey L | title = Field performance of engineered male mosquitoes | journal = Nature Biotechnology | volume = 29 | issue = 11 | pages = 1034–7 | date = October 2011 | pmid = 22037376 | doi = 10.1038/nbt.2019 | s2cid = 30862975 }}</ref><ref>Staff (March 2011) [https://web.archive.org/web/20111110150441/http://www.oxitec.com/wp-content/uploads/2011/03/OXITEC-Newsletter-March-11-Final.pdf "Cayman demonstrates RIDL potential"]. ''Oxitec Newsletter'', March 2011. Retrieved 20 September 2011</ref><ref name="Knapton" /> Another approach is to use a [[sterile insect technique]], whereby males genetically engineered to be sterile out compete viable males, to reduce population numbers.<ref>{{cite journal | vauthors = Benedict MQ, Robinson AS | title = The first releases of transgenic mosquitoes: an argument for the sterile insect technique | journal = Trends in Parasitology | volume = 19 | issue = 8 | pages = 349–55 | date = August 2003 | pmid = 12901936 | doi = 10.1016/s1471-4922(03)00144-2 }}</ref>

Other insect pests that make attractive targets are [[moth]]s. [[Diamondback moth]]s cause US$4 to $5 billion of damage each year worldwide.<ref name=":15">{{Cite web|url=https://www.theatlantic.com/science/archive/2017/09/genetically-modified-sterile-insects-take-flight/539040/|title=Genetically Modified Moths Come to New York| vauthors = Zhang S |date=8 September 2017|website=The Atlantic|access-date=23 December 2018}}</ref> The approach is similar to the sterile technique tested on mosquitoes, where males are transformed with a gene that prevents any females born from reaching maturity.<ref>{{Cite web|url=http://blogs.discovermagazine.com/d-brief/2017/05/10/genetic-engineering-moths/|title=After Mosquitos, Moths Are the Next Target For Genetic Engineering|vauthors=Scharping N|date=10 May 2017|website=[[Discover (magazine)|Discover]]|access-date=23 December 2018|archive-date=11 November 2019|archive-url=https://web.archive.org/web/20191111080853/http://blogs.discovermagazine.com/d-brief/2017/05/10/genetic-engineering-moths/|url-status=dead}}</ref> They underwent field trials in 2017.<ref name=":15" /> Genetically modified moths have previously been released in field trials.<ref>{{cite journal | vauthors = Reeves R, Phillipson M |date = January 2017 |title = Mass Releases of Genetically Modified Insects in Area-Wide Pest Control Programs and Their Impact on Organic Farmers |journal=Sustainability|volume=9|issue=1|pages=59|doi=10.3390/su9010059 |doi-access=free|bibcode = 2017Sust....9...59R }}</ref> In this case a strain of [[pink bollworm]] that were sterilized with radiation were genetically engineered to express a [[Green fluorescent protein|red fluorescent protein]] making it easier for researchers to monitor them.<ref>{{cite journal | vauthors = Simmons GS, McKemey AR, Morrison NI, O'Connell S, Tabashnik BE, Claus J, Fu G, Tang G, Sledge M, Walker AS, Phillips CE, Miller ED, Rose RI, Staten RT, Donnelly CA, Alphey L | title = Field performance of a genetically engineered strain of pink bollworm | journal = PLOS ONE | volume = 6 | issue = 9 | pages = e24110 | date = 13 September 2011 | pmid = 21931649 | pmc = 3172240 | doi = 10.1371/journal.pone.0024110 | bibcode = 2011PLoSO...624110S | doi-access = free }}</ref>

Silkworm, the larvae stage of ''[[Bombyx mori]]'', is an economically important insect in [[sericulture]]. Scientists are developing strategies to enhance silk quality and quantity. There is also potential to use the silk producing machinery to make other valuable proteins.<ref>{{cite journal | vauthors = Xu H, O'Brochta DA | title = Advanced technologies for genetically manipulating the silkworm Bombyx mori, a model Lepidopteran insect | journal = Proceedings. Biological Sciences | volume = 282 | issue = 1810 | date = July 2015 | pmid = 26108630 | pmc = 4590473 | doi = 10.1098/rspb.2015.0487 | page=20150487}}</ref> Proteins currently developed to be expressed by silkworms include; [[human serum albumin]], [[Collagen alpha-1(IV) chain|human collagen α-chain]], mouse [[monoclonal antibody]] and [[NGLY1|N-glycanase]].<ref>{{cite journal | vauthors = Tomita M | title = Transgenic silkworms that weave recombinant proteins into silk cocoons | journal = Biotechnology Letters | volume = 33 | issue = 4 | pages = 645–54 | date = April 2011 | pmid = 21184136 | doi = 10.1007/s10529-010-0498-z | s2cid = 25310446 }}</ref> Silkworms have been created that produce [[spider silk]], a stronger but extremely difficult to harvest silk,<ref>{{cite journal | vauthors = Xu J, Dong Q, Yu Y, Niu B, Ji D, Li M, Huang Y, Chen X, Tan A | title = Bombyx mori | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 115 | issue = 35 | pages = 8757–8762 | date = August 2018 | pmid = 30082397 | pmc = 6126722 | doi = 10.1073/pnas.1806805115 | doi-access = free }}</ref> and even novel silks.<ref>{{cite web |url= https://www.newscientist.com/article/2165351-gm-worms-make-a-super-silk-completely-unknown-in-nature/ |title= GM worms make a super-silk completely unknown in nature| vauthors = Le Page M |website=New Scientist |access-date=23 December 2018}}</ref>