Question 3: Share information on experience with the host organism (mosquito) that could be useful to considered in the development of the additional voluntary guidance materials.

Argentina is concerned about the formulation of additional risk assessment materials (to those already in existences) for gene drive. For most of the countries that are part of the Protocol, and for those that are not part of it like Argentina, there are only two categories: if the organism is an LMO or if it is not. The evaluations for LMOs include plants, animals (also insects) and microorganisms. Therefore, Argentina considers that with more than 25 years of experience on biosafety and assessment of biotechnological products, it is not necessary to generate additional guidelines, beyond the existing ones for LMOs.

--- Posted on behalf of Dr. Luciana Pimenta Ambrozevicius, Brazil ---

Dear Participants,

Although those are not gene drive examples, the experience with risk assessment of transgenic mosquito could be used to develop guidance materials. For example the commercial approval of Ae. aegypti OX513A: http://ctnbio.mctic.gov.br/liberacao-comercial/-/document_library_display/SqhWdohU4BvU/view/1701211#/liberacao-comercial/consultar-processo.

Another important source is the existing material about the host organism, for example the OECD biology documents such as the CONSENSUS DOCUMENT ON THE BIOLOGY OF MOSQUITO AEDES AEGYPTI ( https://www.oecd-ilibrary.org/environment/safety-assessment-of-transgenic-organisms-in-the-environment-volume-8_9789264302235-en), and other documents about the biology of Anopheles species that are already being developed by OECD WG-HROB.

Are there other examples with mosquitoes that could be useful?

Luciana

Hi! My name is Enrykie Fortajada, a Fellow from the National Committee on Biosafety of the Philippines and I would like to share insights regarding this topic. As mentioned in the paper of Connolly et al (2022), defining the target organisms is crucial in risk assessment of LMO containing gene drive. For the initiative of population suppression gene drive for the control of the human malaria vector Anopheles gambiae, a complex of nine morphologically indistinguishable species of mosquitoes six of which are known to vector human malaria, hybridization between sibling species of the complex can yield fertile hybrids. This led to defining target organism as all nine species of the complex. However, including non-vector species of a complex as part of the defined target organism go beyond the intention to specifically target vectors. Therefore, the definition of target organism in environment risk assessment of gene drive in species complexes requires more nuanced consideration and further refinement than would be the case for more conventional GMO applications.

Reference:
Connolly, J. B., Mumford, J. D., Glandorf, D. C., Hartley, S., Lewis, O. T., Evans, S. W., ... & Aboagye-Antwi, F. (2022). Recommendations for environmental risk assessment of gene drive applications for malaria vector control. Malaria Journal, 21(1), 152.

Brinda Dass- Senior Program Manager at The Foundation for the National Institutes of Health in Maryland, USA commenting on the topic of OECD Biology Document to say that one is currently in preparation for Anopheles gambiae as well and it will be similar in scope to the one on Aedes aegypti that is currently available to use. Please see https://one.oecd.org/document/ENV/JM/BIO(2017)7/en/pdf for details on the outline. Details about the initial meeting organized to start this activity at https://one.oecd.org/document/ENV/JM/BIO/A(2019)2/en/pdf

Thank you.

Hello everybody, my name is Christoph Then and I am a member of ENSSER (The European Network of Scientists for Social and Environmental Responsibility) and representing Testbiotech (http://www.testbiotch.org) in this discussion. Testbiotech compiled recent information in a backgrounder for this forum https://www.testbiotech.org/node/3037. In our backgrounder we suggest to discuss the example of a X-shredder which is supposed to become a test case for the release of self sustaining gene drives.

As outlined in the study on risk assessment application of Annex I of decision CP 9/13 to LMOs containing engineered gene drives, the risk assessment of insects with engineered gene drive systems can build on existing knowledge and experience with vector control programs using insects that do not contain gene drives such as the sterile insect technique (SIT). For example, South Africa’s National Institute for Communicable Diseases has a project aimed at identifying additional vector control strategies. The main objective of the project is to assess and establish proof of concept for using the SIT as a vector control strategy. The long-term goal of the SIT project is to establish an industrial-scale mass rearing facility capable of producing and sterilizing sufficient numbers of sterile male mosquitoes to support a larger area-wide field programme in malaria affected areas in the country and region.
https://www.nicd.ac.za/centres/centre-for-emerging-zoonotic-and-parasitic-diseases/
http://www.parasitesandvectors.com/content/4/1/208
https://doi.org/10.1186/s13071-021-04674-w

Good evening, my name is Heidi Mitchell from the Office of the Gene Technology Regulator (OGTR) in Australia.
Valuable information is available in the scientific literature on different mechanisms of suppressing mosquito populations (such as sterile insect release - either irradiated or GM) or on modifying the mosquitoes to prevent disease transmission (such as the introduction of mosquitoes containing Wolbachia bacteria). The literature on the introduction of these modified mosquitoes should inform any guidance on assessments of gene drive mosquitoes.
Oxitec GM mosquitoes -  https://www.frontiersin.org/articles/10.3389/fbioe.2022.975786 
Wolbachia infected mosquitoes - https://www.worldmosquitoprogram.org/en/learn/scientific-publications; https://www.worldmosquitoprogram.org/sites/default/files/2021-10/Kimberley%20R_._%20Dainty%20_et%20al.%2C%202021.pdf

----Posted on behalf of Mr. Kamal Kumar Rai---

The Voluntary Guidelines good to focus the participatory inclusive approach in accordance with the spirit and objectives of the convention with the five distinct step approach

IPLCs encourage to establish inclusive mechanism and promote the convention’s Article 8G to maintain, regulate, manage or control, explicitly the risks associated with the use and release of living modified organisms including LMOs containing engineering gene drives resulting from biotechnology or modern biotechnology which are likely to have adverse environmental impacts that could affect the conservation.

The Risks Assessment and Risk Management must have mandated IPLCs inclusive within the spirits and objectives of the Convention. Inclusion- participatory case by case approach in socio-economic consideration and cultural appropriateness.

Traditional, Indigenous and local knowledge, practices, innovations of IPLCs are vital complimentary as indigenous sciences for LMO, LMO containing engineering gene drive Risks Assessment and Risks Management and full and effective participation of IPLCs at all level integrating the Article 8(j) within the objectives of the convention. 

The IPLCs observations, experiences on ground and ideas can play an important role for Risk Assessment and Risks management, full and effective participation of IPLCs on the program of work, activities such as capacity building, where they can contribute.

Kamal Kumar Rai
IPLC

Malaria, dengue, Chikungunya and its vectors have been the subject of study for a long time. Their host organisms are well known, and their biology is well characterized. There are ongoing efforts to compile available information to facilitate the work of regulatory authorities and policymakers. Supporting initiatives such as the OECD Consensus Document of the Biology of Mosquito Aedes aegypti is crucial. The report provides an overview of current information on this host organism to help national authorities and scientists evaluate the safety of genetically engineered mosquitoes when released into the environment. A similar exercise is underway for Anopheles gambiae and it would be critical to have a similar report on other species, including Anopheles stephensi. A malaria vector in South-East Asia and large parts of the Arabian Peninsula, this species is now spreading to Africa, threatening gains previously made in the region towards malaria eradication.

• OECD Consensus Document of the Biology of Mosquito Aedes aegypti. Available at https://one.oecd.org/document/env/jm/mono(2018)23/en/pdf ;

• OECD Consensus Document on the Biology of Mosquito Anopheles gambiae. Available at https://one.oecd.org/document/ENV/JM/BIO/A(2019)2/en/pdf.

Sincerely

I provide publications that would further the discussion on requirements for engineered gene drive insect dossiers-

Defining transformation events for gene drive in species complexes
John B. Connolly. Modern Biotechnology in Integrated Plant Production
IOBC-WPRS Bulletin Vol. 163, 2023. pp. 8-20

Gene drive in species complexes: defining target organisms.
Connolly JB, Romeis J, Devos Y, Glandorf DCM, Turner G, Coulibaly MB.
Trends Biotechnol. 2023 Feb;41(2):154-164. doi: 10.1016/j.tibtech.2022.06.013. Epub 2022 Jul 19.

Regulatory and policy considerations for the implementation of gene drive-modified mosquitoes to prevent malaria transmission.
James SL, Dass B, Quemada H.
Transgenic Res. 2023 Apr;32(1-2):17-32. doi: 10.1007/s11248-023-00335-z. Epub 2023 Mar 15.

Points to consider in seeking biosafety approval for research, testing, and environmental release of experimental genetically modified biocontrol products during research and development.
Tonui WK, Ahuja V, Beech CJ, Connolly JB, Dass B, Glandorf DCM, James S, Muchiri JN, Mugoya CF, Okoree EA, Quemada H, Romeis J.
Transgenic Res. 2022 Dec;31(6):607-623. doi: 10.1007/s11248-022-00311-z. Epub 2022 Oct 4.

many thanks
Brinda Dass, Senior Program Manager, Foundation for the National Institutes of Health, Maryland, USA

Hello, Leocris Batucan from the National Committee on Biosafety of the Philippines.

I would like to share this research on spatial and temporal distribution of mosquitoes in a tropical island: https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-020-04326-5.

Though varying spatio-temporal dynamics have long been noted in mosquitoes, it would be best if this information is stressed and given prominence in guidance materials. This has far reaching implications as it affects surveillance, pest management, resource allocation, etc.

Hello everyone,

I am Christophe Boëte a research scientist based at the Institute of Evolutionary Science of Montpellier, France.
Regarding the message posted by Lic. Facundo Simeone, Argentina, I want to stress out that with LMO harbouring certain types of gene drive systems, the question of their spread (including their speed at modifying the targeted populations) and their spatial (including their transboudary movements) and temporal containments can be much more acute than for the current LMOs. This needs to be taken taken into account into any guidance material.

Dear all,

The risk of gene drives contaminating another species has been mentioned in a number of publications in the past and a recent publication has been examining it in detail in order to evaluate the probability of occurrence of a drive sequence escaping from the target species and contaminating another species. This is a key issue to be considered in any guidance material.
Here is the related reference:

Courtier-Orgogozo V, Danchin A, Gouyon PH, Boëte C. Evaluating the probability of CRISPR-based gene drive contaminating another species. Evol Appl. 2020 Apr 17;13(8):1888-1905. doi: 10.1111/eva.12939.

and it is available online here: https://onlinelibrary.wiley.com/doi/10.1111/eva.12939

Christophe Boëte

Hello, my name is Dr. Silke Fuchs and I am a Regulatory Scientist at Imperial College London with a background in molecular mosquito genetics. I work on the Target Malaria project. 
I would like to add information to some of the points raised in previous comments about research by Target Malaria. Target Malaria is working to develop a gene drive mosquito to help control malaria transmission in Africa. As part of our work, we have undertaken to start mapping and assessing possible risks early on, as a way to inform our research and to get feedback from different stakeholders. The information contained in the two papers we published in the last 2 years (Connolly et al., 2021: “Systematic identification of plausible pathways to potential harm via problem formulation for investigational releases of a population suppression gene drive to control the human malaria vector Anopheles gambiae in West Africa” and Connolly et al., 2022a: “Recommendations for environmental risk assessment of gene drive applications for malaria vector control”) as a result provide useful insights into the topics that possible guidance could address. It is broadly consistent with the recommendations earlier made by EFSA (EFSA, 2020), noting the need for additional guidance on issues related to the temporal and spatial spread of gene drive organisms (persistence, spread, predictability and transboundary movements), molecular characterization, and monitoring efforts. It also agrees with the post by Dr. Dass #11583 that the problem formulation should also incorporate the outcomes of appropriate stakeholder engagement as their expertise, concerns and priorities can help identify and assess potential benefits and harms.
While our research is ongoing, it is important to note that no application for field release has been made to this date and the strains are still being characterised.

Lessons learned from our work show that it is important to start early and that as the scientific process is iterative, it is normal that findings be refined over time. Challenges identified at one stage (for example with potential resistance) enables feedback into the R&D process and further scientific investigation.

As mentioned by post Dr. James #11577, Dr. Ambrozevicius #11546, Dr. Mitchell  #11565 and Ms Mogapi #11558 it is possible to build from previous experiences on risk assessments with other genetically modified (non-gene drive) mosquitoes. Examples include for example the Technical evaluation of a potential release of OX513A Aedes aegypti mosquitoes on the island of Saba (National Institute of Public Health and the Environment (RIVM), 2017) and “Risk Assessment for Controlling Mosquito Vectors with Engineered Nucleases: Controlled field release for Sterile Male Construct Risk assessment final report” (Hayes et al., 2018). The latter strain was developed by the Target  Malaria team.

Finally, the issue of defining target species is indeed very important. Our team has been actively engaged in thinking about how to define target organisms. As mentioned by other participants in this forum ( #11548) Connolly et al (2022a) published an article about the definition of target organisms for gene drives in species complexes, which has already been cited by other participants in this forum.  In the case of malaria mosquitoes, An. gambiae was recognised as a single species in 1975. However, reflecting an ongoing speciation process in the field, the single species was subsequently re-classified in 2013 into two different species, An. gambiae sensu stricto (s.s.) and An. coluzzii (Coetzee et al., 2013). However, because of the close evolutionary relationship between An. gambiae s.s. and An. coluzzii, interspecific hybrids are still routinely found in the wild, albeit at low frequencies (White 1971 and 1974; Costantini et al., 2009). The phenomenon of “porous species boundaries” has been well-established for many years in the An. gambiae s.l. species complex, as well as other insects (Connolly et al., 2022b; Besansky et al., 2003). These are all well documented elements that would be taken into account in a risk assessment.

Useful documents include:

Besansky NJ, Krzywinski J, Lehmann T, Simard F, Kern M, Mukabayire O, Fontenille D, Toure Y, Sagnon N: Semipermeable species boundaries between Anopheles gambiae and Anopheles arabiensis: evidence from multilocus DNA sequence variation. Proc Natl Acad Sci U S A 2003, 100:10818-10823. https://doi.org/10.1073/pnas.143433710

Coetzee M, Hunt RH, Wilkerson R, Torre AD, Coulibaly MB, Besansky NJ: Anopheles coluzzii and Anopheles amharicus, new members of the Anopheles gambiae complex. Zootaxa 2013, 3619:246-274.  https://pubmed.ncbi.nlm.nih.gov/26131476/

Connolly JB, Mumford JD, Fuchs S, Turner G, Beech C, North AR, Burt A: Systematic identification of plausible pathways to potential harm via problem formulation for investigational releases of a population suppression gene drive to control the human malaria vector Anopheles gambiae in West Africa. Malar J 2021, 20. doi:10.1186/s12936-021-03674-6.

Connolly JB, Mumford JD, Glandorf DCM, Hartley S, Lewis OT, Evans SW, Turner G, Beech C, Sykes N, Coulibaly MB, et al: Recommendations for environmental risk assessment of gene drive applications for malaria vector control. Malar J 2022a, 21:152. doi:10.1186/s12936-022-04183-w.

Connolly JB, Romeis J, Devos Y, Glandorf DCM, Turner G, Coulibaly MB: Gene drive in species  complexes: defining target organisms. Trends Biotechnol 2022b. https://doi.org/10.1016/j.tibtech.2022.06.013.

Costantini C, Ayala D, Guelbeogo WM, Pombi M, Some CY, Bassole IH, Ose K, Fotsing JM, Sagnon N, Fontenille D, et al: Living at the edge: biogeographic patterns of habitat segregation conform to speciation by niche expansion in Anopheles gambiae. BMC Ecol 2009, 9:16. https://doi.org/10.1186/1472-6785-9-16

EFSA (European Food Safety Authority), Devos, Y, Bonsall, MB, Nogué, F, Paraskevopoulos, K, Wimmer, EA, Firbank, LG, 2020. Outcome of a public consultation on the draft adequacy and sufficiency evaluation of existing EFSA guidelines for the molecular characterisation, environmental risk assessment and post-market environmental monitoring of genetically modified insects containing engineered gene drives. EFSA Supporting publication 2020: 17( 11): EN-1939. 315 pp. doi: 10.2903/sp.efsa.2020.EN-1939

Hayes, Keith R., Geofrey R. Hosack, Adrien Ickowicz, Scott Foster, David Peel, Jessica Ford, and Ronald Thresher. Risk Assessment for Controlling Mosquito Vectors with Engineered Nucleases: Controlled field release for Sterile Male Construct Risk assessment final report. Hobart, 2018. https://doi.org/10.25919/v424-4k80

National Institute for Public Health and the Environment. Technical evaluation of a potential release of OX513A Aedes aegypti mosquitoes on the island of Saba. 2017. https://www.rivm.nl/bibliotheek/rapporten/2017-0087.pdf

White GB: Chromosomal evidence for natural interspecific hybridization by mosquitoes of the Anopheles gambiae complex. Nature 1971, 231:184-185. https://doi.org/10.1038/231184a0

White GB: Anopheles gambiae complex and disease transmission in Africa. Transactions of the Royal Society of Tropical Medicine and Hygiene 1974, 68:278-298. https://doi.org/10.1016/0035-9203(74)90035-2

Hello all, I am Margareth Capurro from University of São Paulo, Brazil.  I am a molecular biologist that develop transgenic lines to be used as biological control. At this forum the discussion is about how gene drive can be safe and be controlled but it is my opinion that all “mosquito-bio-products” should be included as examples (suppression and Wolbachia introduction).
First question: Wolbachia introduction is a gene drive form?
Also, the mosquito environment (urban or sylvatic). Urban mosquitos have an ecological impact on the environment?
We need to think about how this technology can be used in short, medium, and long term.
Strains that produce population suppression have the goal to kill mosquitos. Strains that produce refractoriness or block pathogens transmission have the goal to eradicate the associated diseases. This two bioproducts should work together as an integrate control.
Is predicted for the success of population replacement, a previous population suppression. Less mosquitoes to be replaced. After, or even during the population replacement, the disease is going to be affected, but at the same time the mosquito population can not increase. The idea is the usage of population suppression to control mosquito bites. This is a unique situation how to use the new technology and all the information that we have to calculate risks and safety.

Dear all,

Thank you very much for the interesting discussion so far. I am Naomi Kosmehl from the Foundation of future farming/Save Our Seeds, Berlin – Germany.

As some of the most advanced gene drive mosquitoes are developed for the use against the anopheles gambiae sensu strictu mosquito, we would like to point to a relevant publication (https://doi.org/10.1016/j.tibtech.2022.06.013). It indicates that the gene drive would most likely be able to spread to the entire anopheles gambiae sensu lato complex, comprising 9 vector and non-vector mosquito species. These mosquitoes have shown in the past to interbreed and create fertile offspring. This has already been troublesome for the fight against malaria as it has been shown to lead to the exchange of mutations that help the survival of species within the complex. For example, Anopheles arabiensis acquired genes that make it resistant to dry and arid conditions through A. gambiae s.s and A. coluzzi, and A. coluzzi acquired a gene for insecticide resistance through A. gambiae s.s (https://doi.org/10.1038/s41598-019-49065-5 DOI: 10.1126/science.1258524 https://doi.org/10.1371/journal.pone.0034841).

There is limited research conducted on the anopheles gambiae s.l. and its role for the ecosystem. They do play a role in pollination (DOI: 10.1146/annurev.en.40.010195.002303 ). Furthermore 2,9% of the African Anopheles Gambiae have a mutation in the double sex gene researchers are currently targeting (https://doi.org/10.1038/nature24995), that should be relevant for risk assessment and the potential for mosquitoes to develop resistances to gene drives.

We would like to point to Christoph Then’s (Testbiotech) submission (#11554) to this forum on the x-shredder used in mosquitoes (https://bch.cbd.int/en/database/SUB/BCH-SUB-SCBD-263607). Showing that gene editing was conducted on wrong assumptions, his submission highlights the difficulties of genome assembly for highly polymorphic genomes, such as mosquitoes, and the need for accuracy in genome sequencing data.

Relevant for the risk assessment of the host organism is their potential for windborne migration over hundreds of kilometers (DOI: 10.1038/s41586-019-1622-4 ). Furthermore researchers have found that the anopheles stephensi, originating from Asia, has spread to the horn of Africa and into close proximity to the anopheles gambiae complex (https://doi.org/10.1186/s12936-022-04197-4 ). Both findings would require the risk assessment to look beyond the target organism and release area.

As research on gene drive mosquitoes and risk assessment is often based on the premise of “random mating” we would like to point out that assortative mating through different swarming patterns and times has been observed in the Anopheles gambiae s.s species (DOI: 10.1111/j.1365-2915.2012.01049.x ) and could support risk assessment.

Another relevant aspect related to mosquitoes is the phenomenon of horizontal gene transfer (HGT) that could lead to an interspecies spread beyond mating. HGT is a common phenomenon; a recent study examined 218 genomes from different insects and identified at least 741 separate gene transfers, which transferred around 1410 genes (DOI: 10.1016/j.cell.2022.06.014 ). The possibility of the whole gene drive construct or only part of it to be transferred should be examined. Especially because the doublesex gene is often targeted for gene drive mosquitoes and this gene is the same for all insects. This could have devastating effects because every insect is theoretically vulnerable to changes in this gene should something be passed on by an event of HGT (https://doi.org/10.1038/srep13068).

It seems that for thorough risk assessment to be conducted, more information on the host organism and its role in the ecosystem, its migratory patterns, potential outcrossing to other species (and continents), frequency of horizontal gene transfer, and potentials to mutation/resistance need to be further assessed.

Dear colleagues
is important to highlight that guidance on 'living-modified mosquitoes species that act as vectors of human and animal diseases' has already been produced under a previous AHTEG, and the guidance is linked to several important background materials
some  useful links on Anopheles gambiae (Malaria mosquito)

• NCBI Taxonomy Browser - Anopheles gambiae https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=7165&lvl=3&p=has_linkout&p=blast_url&p=genome_blast&lin=f&keep=1&srchmode=1&unlock
• NCBI Genome - Anopheles gambiae (African malaria mosquito) https://www.ncbi.nlm.nih.gov/genome/?term=txid7165%5bOrganism:exp%5d
• Malaria Atlas https://malariaatlas.org/
• UniProtKB - Taxonomy - Anopheles gambiae (African malaria mosquito) https://www.uniprot.org/taxonomy/7165
• PLOS Pathogens - A New Chromosomal Phylogeny Supports the Repeated Origin of Vectorial Capacity in Malaria Mosquitoes of the Anopheles gambiae Complex https://doi.org/10.1371/journal.ppat.1002960
• Communications Biology - Transcontinental dispersal of Anopheles gambiae occurred from West African origin via serial founder events https://doi.org/10.1038/s42003-019-0717-7
• Parasites & Vectors - A global map of dominant malaria vectors https://doi.org/10.1186/1756-3305-5-69
• Scientific Reports - Ecological drivers of genetic connectivity for African malaria vectors Anopheles gambiae and An. arabiensi https://doi.org/10.1038/s41598-020-76248-2
• University of Florida Department of Entomology & Nematology - African malaria mosquito https://entnemdept.ufl.edu/creatures/AQUATIC/anopheles_gambiae.htm
• Geospatial Health - The spatial distribution of Anopheles gambiae sensu stricto and An. arabiensis (Diptera: Culicidae) in Mali https://pubmed.ncbi.nlm.nih.gov/18686246/
• Current Opinion in Microbiology - Anopheles gambiae pathogen susceptibility: The intersection of genetics, immunity and ecology https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3404259/
• PLOS ONE - The Effect of Temperature on Anopheles Mosquito Population Dynamics and the Potential for Malaria Transmission https://doi.org/10.1371/journal.pone.0079276
• Parasites & Vectors - Relationship between temperature and Anopheles gambiae sensu lato mosquitoes' susceptibility to pyrethroids and expression of metabolic enzymes https://doi.org/10.1186/s13071-022-05273-z
• PLOS ONE - Anthropogenic Habitat Disturbance and Ecological Divergence between Incipient Species of the Malaria Mosquito Anopheles gambiae https://doi.org/10.1371/journal.pone.0039453
• Parasites & Vectors - Predatory and competitive interaction in Anopheles gambiae sensu lato larval breeding habitats in selected villages of central Uganda https://doi.org/10.1186/s13071-021-04926-9
• Journal of Biosafety and Biosecurity - Potential geographical distribution of Anopheles gambiae worldwide under climate change https://doi.org/10.1016/j.jobb.2021.08.004
• Annals of the New York Academy of Sciences - The Ecology of Anopheles Mosquitoes under Climate Change: Case Studies from the Effects of Environmental Changes in East Africa Highlands https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767301/

O.A.El-kawy

Dear participants,

My name is Samson Simon, I work for the German Federal Agency for Nature Conservation (BfN) as a biosafety expert.

If mosquitoes are to be suppressed by a gene drive is paramount to understand the natural role of mosquitos in ecosystems and their role in food webs. However, although the general role of mosquitoes for other species is known (e.g. food for other arthropods, for bats and some birds) we do not understand the magnitude of knock-on effects which may be linked to the suppression of mosquitoes over a larger spatial scale. Some data on the ecological role of mosquitoes in Germany and France can be found in Theissinger et al. 2019 (doi.org/10.1111/mec.15214), Brühl et al. 2020 (doi.org/10.1016/j.scitotenv.2020.137800) or Poulin et al. 2012 (https://doi.org/10.1016/j.actao.2011.11.005).

Dears,

Please find below two relevant publications on experience gained with mosquitoes that could be useful to consider in the development of additional voluntary guidance materials.

-2022 – Gene drive in species complexes: defining target organisms – Trends in Biotechnology – http://dx.doi.org/10.1016/j.tibtech.2022.06.013
-2019 – Effects of the removal or reduction in density of the malaria mosquito, Anopheles gambiae s.l., on interacting predators and competitors in local ecosystems – Medical and Veterinary Entomology – https://doi.org/10.1111/mve.12327

We hope the information shared will be helpful.

Wishing you all the best,

Yann Devos (Senior scientific officer in the Chief Scientist Office of the European Food Safety Authority (EFSA)) and Alexandre Huchelmann (Policy officer in the Biotechnology Unit of the Directorate-General for Health and Food Safety (DG SANTE) of the European Commission)

Greetings colleagues!!

My name is Efrain Torres Ariza from Colombia, I currently work in the genetic resources group of the Ministry of the Environment.

Here are some references that may be useful:

OECD (2018), Safety Assessment of Transgenic Organisms in the Environment, Volume 8: OECD Consensus Document of the Biology of Mosquito Aedes aegypti, Harmonisation of Regulatory Oversight in Biotechnology, OECD Publishing, Paris, https://doi.org/10.1787/9789264302235-en. https://www.oecd-ilibrary.org/environment/safety-assessment-of-transgenic-organisms-in-the-environment-volume-8_9789264302235-en

WHO (2021). Guidance framework for testing of genetically modified mosquitoes, second edition. https://www.who.int/publications/i/item/9789240025233.

Among the forty documents identified by previous posts (at the time of my writing this) two – Connolly et al. (2023) and Organisation for European Cooperation and Development (2018) – are cited four and three times respectively (Table Q3). I support the emphasis on the OECD consensus for document Ae. aegypti, and I look forward to the forthcoming equivalent document for An. gambiae. Both of these documents and Connolly et al. (2023) should be on a recommended reading list of any future guidance document.

I have found publications that report the results of laboratory experiments, field trials or entomological surveys, and systematic reviews, to be useful the during risk assessments for transgenic (but not gene drive) mosquitoes that my team and I have conducted. There are too many of these publications to cite here individually but some exemplars of the four cases would include:

• laboratory trials: Facchinelli et al. (2019) and Pollegioni et al. (2020)
• field trials: Epopa et al. (2017) and Yao et al. (2022)
• entomological surveys: Pombi et al. (2017) and Epopa et al. (2020)
• systematic reviews: Collins et al. (2018) and Qureshi and Connolly (2021)

The utility of these types of publications underlines to me the importance of the phased release strategy recommended for gene drive modified mosquitoes (James et al. (2018), WHO-TDR & FNIH (2021)), and the necessity of gathering field observations and conducting contained trials with transgenic mosquitoes and their wild-type comparators.


REFERENCES
Connolly, John B., Jörg Romeis, Yann Devos, Debora C. M. Glandorf, Geoff Turner, and Mamadou B. Coulibaly. 2023. “Gene Drive in Species Complexes: Defining Target Organisms.” Trends in Biotechnology 41 (2): 154–64. https://doi.org/10.1016/j.tibtech.2022.06.013.

Organisation for European Cooperation and Development. 2018. Safety Assessment of Transgenic Organisms in the Environment, Volume 8. OECD. https://doi.org/10.1787/9789264302235-en.

Facchinelli, Luca, Ace R. North, C. Matilda Collins, Miriam Menichelli, Tania Persampieri, Alessandro Bucci, Roberta Spaccapelo, Andrea Crisanti, and Mark Q. Benedict. 2019. “Large-cage assessment of a transgenic sex-ratio distortion strain on populations of an African malaria vector.” Parasites & Vectors 12: 70. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6366042/.

Pollegioni, Paola, Ace R. North, Tania Persampieri, Alessandro Bucci, Roxana L. Minuz, David Alexander Groneberg, Tony Nolan, Philippos-Aris Papathanos, Andrea Crisanti, and Ruth Müller. 2020. “Detecting the Population Dynamics of an Autosomal Sex Ratio Distorter Transgene in Malaria Vector Mosquitoes.” Journal of Applied Ecology 57 (10): 2086–96. https://doi.org/https://doi.org/10.1111/1365-2664.13702.

Epopa, Patric Stephane, Abdoul Azize Millogo, Catherine Matilda Collins, Ace North, Frederic Tripet, Mark Quentin Benedict, and Abdoulaye Diabate. 2017. “The Use of Sequential Mark-Release-Recapture Experiments to Estimate Population Size, Survival and Dispersal of Male Mosquitoes of the Anopheles Gambiae Complex in Bana, a West African Humid Savannah Village.” Parasites & Vectors 10: 376.

Yao, Franck Adama, Abdoul-Azize Millogo, Patric Stephane Epopa, Ace North, Florian Noulin, Koulmaga Dao, Mouhamed Drabo, et al. 2022. “Mark-Release-Recapture Experiment in Burkina Faso Demonstrates Reduced Fitness and Dispersal of Genetically-Modified Sterile Malaria Mosquitoes.” Nature Communications 13: 796. https://doi.org/10.1038/s41467-022-28419-0.

Pombi, Marco, Pierre Kengne, Geoffrey Gimonneau, Billy Tene-Fossog, Diego Ayala, Colince Kamdem, Federica Santolamazza, et al. 2017. “Dissecting Functional Components of Reproductive Isolation Among Closely Related Sympatric Species of the Anopheles Gambiae Complex.” Evolutionary Applications 10 (10): 1102–20. https://doi.org/10.1111/eva.12517.

Epopa, Patric Stephane, Abdoul Azize Millogo, Catherine Matilda Collins, Ace R. North, Mark Quentin Benedict, Frederic Tripet, Samantha O’Loughlin, Roch K. Dabiré, Georges Anicet Ouédraogo, and Abdoulaye Diabaté. 2020. “Anopheles Gambiae (s.l.) Is Found Where Few Are Looking: Assessing Mosquito Diversity and Density Outside Inhabited Areas Using Diverse Sampling Methods.” Parasites & Vectors 13: 516.

Collins, C. M., J. A. S. Bonds, M. M. Quinlan, and J. D. Mumford. 2018. “Effects of the Removal or Reduction in Density of the Malaria Mosquito, Anopheles Gambiae, on Interacting Predators and Competitors in Local Ecosystems.” Medical and Veterinary Entomology 33 (1): 1–15. https://doi.org/10.1111/mve.12327.

Qureshi, Alima, and John B. Connolly. 2021. “A systematic review assessing the potential for release of vector species from competition following insecticide-based population suppression of Anopheles species in Africa.” Parasites & Vectors 14 (1). https://doi.org/10.1186/s13071-021-04975-0.

James, Stephanie, Frank H. Collins, Philip A. Welkhoff, Claudia Emerson, H. Charles J. Godfray, Michael Gottlieb, Brian Greenwood, et al. 2018. “Pathway to Deployment of Gene Drive Mosquitoes as a Potential Biocontrol Tool for Elimination of Malaria in Sub-Saharan Africa: Recommendations of a Scientific Working Group .” The American Journal of Tropical Medicine and Hygiene 98 (6_Suppl): 1–49. https://doi.org/10.4269/ajtmh.18-0083.

WHO-TDR & FNIH. 2021. “Guidance Framework for Testing of Genetically Modified Mosquitoes, Second Edition.” World Health Organisation, Geneva, Switzerland.

APPENDIX
Table Q3: Summary of citations identified by participants in relation to Question 3 during the open-ended online forum on risk assessment risk assessment of living modified organisms containing engineered gene drives
Reference Count
Connolly2023 4
OECD2018 3
AGC2017 1
Barron2019 1
Besansky2003 1
Bruehl2020 1
Coetzee2013 1
Collins2018 1
Connolly2021 1
Connolly2022 1
Connolly2023a 1
Costantini2009 1
CourtierOrgogozo2020 1
Dabire2013 1
Dainty2021 1
EFSA2020 1
Foster1995 1
Fouet2012 1
Glandorf2017 1
Hayes2018 1
Huestis2019 1
James2023 1
Kaiser2021 1
Li2020 1
Li2022 1
Mnzava2022 1
Munhenga2011 1
Poulin2012 1
Price2015 1
Spinner2022 1
Theissinger2019 1
Tonui2022 1
White1971 1
White1974 1
WTF2021 1

Good morning, I am Sharmila Buldewo, Scientific Officer at the Food Technology Laboratory, Mauritius.

GDMI appears to be a complex system. It is important to consider how to quantify all uncertainties especially as the risk assessment would be based on existing information or on models. In the latter case, there would be absence of literature on how to predict the real effects or behaviour of the release GDMI.  Details of the post release monitoring need to be clear and cover all the uncertainties or underestimated risks.

I found the following reading materials very enriching:
1. Yann Devos, John D. Mumford, Michael B. Bonsall, Debora C.M. Glandorf, Hector D. Quemada, Risk management recommendations for environmental releases of gene drive modified insects, Biotechnology Advances, https://doi.org/10.1016/j.biotechadv.2021.107807.
2. Rebeca Carballar-Lejarazú, Christian Ogaugwu Taylor Tushar  and Anthony A. James 2020. Next-generation gene drive for population modification of the malaria vector mosquito, Anopheles gambiae. (2020).  https://doi.org/10.1073/pnas.2010214117
3.Sarah Hartley, Adam Kokotovich, Caroline McCalman Prescribing engagement in environmental risk assessment for gene drive technology (2022) https://doi.org/10.1111/rego.12452
4.Sarah Wolf, Jana Collatz, Jürg Enkerli, Franco Widmer, Jörg Romeis Assessing potential hybridization between a hypothetical gene drive-modified Drosophila suzukii and nontarget Drosophila species (2023) https://doi.org/10.1111/risa.14096
Regards
Sharmila