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Emerging Technologies
Published in Sylvia Uzochukwu, Nwadiuto (Diuto) Esiobu, Arinze Stanley Okoli, Emeka Godfrey Nwoba, Christpeace Nwagbo Ezebuiro, Charles Oluwaseun Adetunji, Abdulrazak B. Ibrahim, Benjamin Ewa Ubi, Biosafety and Bioethics in Biotechnology, 2022
Gene drives are engineered snippets of DNA that can be introduced into an organism’s genome to significantly increase the chance that a desired genetic trait will spread through a population faster than would normally happen through sexual reproduction (Friedman et al., 2020). Gene-drive techniques have already been demonstrated in laboratories to effectively alter Anopheles mosquito populations so that they can no longer transmit malaria parasites (Gantz et al., 2015), and also to introduce lethal gene sequences that suppress and rapidly crash entire mosquito populations in laboratories (Hammond et al., 2016). Mathematical evaluations of these approaches indicate that, if combined with existing interventions like LLINs, these technologies can effectively eliminate malaria in several African settings within a few years after the initial releases of even small numbers of modified mosquitoes (Eckhoff et al., 2016). It is particularly important to emphasize that the use of transgenic mosquitoes of any kind, as with any other vector control tool, should be considered as just one component of an integrated approach, rather than as stand-alone technology (Marshall and Taylor, 2009).
Genome Editing and Gene Therapies: Complex and Expensive Drugs
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2020
Hammond et al. (2016) employed CRISPR and TALEN nucleases to target successfully and selectively coding sequence of three genes that confer a recessive female sterility phenotype upon disruption in the malaria mosquito vector Anopheles gambiae. This targeting of female reproduction is an example of adapting genome editing to gene drive technologies. A gene drive may be engineered to reduce the potential of an insect vector population to transmit disease or to impair its reproduction potential and provides a means to transform natural populations without permanent human intervention (Hammond and Galizi, 2017). Kyrou et al. (2018) proposed to employ CRSPR/Cas for the eradication of the malaria vector Anopheles gambiae by deactivating the gene doublesex (AgdsxF) of Anopheles females via CRSPR/Cas-mediated targeting of the intron 4-exon 5 boundary. Under laboratory conditions the mutated gene spread rapidly resulting in reduced egg production and a total collapse of population within 7 to 11 generations.
Does Health Promotion Harm the Environment?
Published in The New Bioethics, 2020
Cheryl C. Macpherson, Elise Smith, Travis N. Rieder
The second method introduces a gene into the mosquito population that prevents them from carrying or transmitting a targeted disease such as malaria. It has only been tested in the laboratory and uses a gene drive system to increase the prevalence of the gene in the population (Hammond and Galizi 2017). A gene drive is a relatively new technology designed to alter the genetics of a target species. It may have long term consequences for the target species because genetic material is transmitted to future generations. It may also affect species that prey on mosquitoes in unknown and unanticipated ways and potentially disrupt the food web. It raises ethical questions involving risks, limitations, and responsibilities. First, for example, genetically modifying mosquitoes with a gene drive might not work as intended and could cause genetic changes that make the mosquitoes more likely to transmit diseases to humans. Second, the targeted pathogen might evolve in response to changes in the mosquito population and become more virulent or deadly. Third, horizontal gene transfer could move the gene drive system from the mosquito population into other populations and have unpredictable genetic and phenotypic effects on a range of species. Although horizontal gene transfer is rare, the consequences for human or environmental health are unknown and potentially significant.
Identifying and detecting potentially adverse ecological outcomes associated with the release of gene-drive modified organisms
Published in Journal of Responsible Innovation, 2018
Keith R. Hayes, Geoffrey R. Hosack, Genya V. Dana, Scott D. Foster, Jessica H. Ford, Ron Thresher, Adrien Ickowicz, David Peel, Mark Tizard, Paul De Barro, Tanja Strive, Jeffrey M. Dambacher
Gene drive is a generic term for a variety of processes that in sexually reproducing organisms cause genes to be transmitted to successive generations at ratios greater than the classical Mendelian ratio (Champer, Buchman, and Akbari 2016). Natural gene drive processes, such as under dominance and Homing Endonuclease Genes (HEGs), have been known for many decades (Zimmering, Sandler, and Nicoletti 1970), and identified as mechanisms to suppress or modify populations of disease vectors (Wood and Newton 1991; Braig and Yan 2002; Burt 2003; Gould, Magori, and Huang 2006; Lindholm et al. 2016). Harnessing natural drive mechanisms to achieve vector control, however, has proven to be difficult (Smidler, Min, and Esvelt 2017), but this situation could change due to the development of RNA-guided endonucleases such as CRISPR/Cas9 (Jinek et al. 2012).
A roadmap for gene drives: using institutional analysis and development to frame research needs and governance in a systems context
Published in Journal of Responsible Innovation, 2018
J. Kuzma, F. Gould, Z. Brown, J. Collins, J. Delborne, E. Frow, K. Esvelt, D. Guston, C. Leitschuh, K. Oye, S. Stauffer
Gene drive systems also match other uses of the IAD Framework according to several criteria (Ostrom 2009): they (1) involve institutional arrangements in collective action settings, and for intentional release, gene drives will require ongoing cooperation between different sectors and geographic regions to plan for, execute, and monitor gene drive releases and their impacts; (2) exhibit the nonexcludability property described above; (3) utilize institutions that are not necessarily formal but rather defined by organization and rules that guide interactions, such as farming communities or conservation groups; and (4) start with a shared problem that people are trying to solve, such as species loss or invasive pest destruction in ecosystems. The goals of most current gene drive projects focus on widely shared social goals such as protecting endangered species or combating insect-borne diseases. With first-generation genetically engineered organisms (GEOs), motives were more profit-focused (eg to sell more agricultural seeds and chemicals). Gene drives are so far being developed for wider social and ecological problems, like aiming to ameliorate mosquito-borne disease, decrease ecosystem harm from invasive species, or protect endangered species.