Seite - 103 - in Critical Issues in Science, Technology and Society Studies - Conference Proceedings of the 17th STS Conference Graz 2018

are genotypic wild types. This gives the fsRIDL approach both a short-term self-sustaining but ultimately a self-limiting character [2]. The RIDL technique has some vulnerabilities which especially in the case of dengue, are quite numerous. Already there have been test trials on the Cayman Islands, Malaysia and Brazil [16]. These revealed that the mating capabilities of the released GMOs are quite limited – with a competitiveness of 56% in comparison to wild males [17]. Additionally, there is the danger to spread antibiotic resistances because the GMOs need to be fed with this antibiotic in the laboratory in order to suppress the lethal gene. This is also a major culprit. Because tetracycline is widely used in animal feed production it can be found in the environment and sewage so that up to 15% of RIDL-females were viable when fed on cat food [18]. Besides these drawbacks, an eradication of one vector species Aedes aegyptii in the case of a successful RIDL application, allows the other vector species Aedes albopictus to spread [16]. Furthermore a reduction in the vector species might result in reduced cross- and herd-immunities and thereby favoring a more serious and deadly disease variant including hemorrhagic fevers [19]. Furthermore, there is the problem of spread to other populations, which again is especially probable in a population consisting mainly of male fsRIDL mosquitoes with a dwindling percentage of females. The gene product of the lethal gene was shown to be neurotoxic in mice [20]. Therefore, it might be possible to negatively affect predators. Moreover, there have been some errors in release as the mechanical sex sorting failed in 0,33% which is quite a lot considering that in the Cayman Islands a total of around 10 million mosquitoes were released [21]. Furthermore, the lethal gene does not seem to work in about 3% of cases [18]. Invasive Species in New Zealand The last example for a possible gene drive application targets the invasive predators in New Zealand which damage the indigenous flora and fauna. Therefore, New Zealand’s initiative predator free 2050 is planning to get rid of invasive species until 2050 [22]. Currently, New Zealand is conducting multiple techniques such as the sterile male technique, live trapping, poisoning and maybe in the future the so called Trojan female technique [23]. The most dreaded invasive species are rodents, especially rats, stoats and possums. In this regard, the application of a gene drive (possibly one that is based on CRISPR/Cas) is considered. A major problem in this case is confinement. Since these animals mostly stowed away on ships to get to New Zealand, gene drive organisms might use the same means of transportation to reach the rest of the world. This might result in a global diffusion of a gene drive that ultimately might exterminate all rats and potentially have devastating effects on ecosystems worldwide. A related problem would be the smuggling of a gene drive. Because these rodents are globally considered as pests and although they cause a net damage of about 50 million dollars in New Zealand the damage they cause in the USA of around 19 billion dollars is quite steeper. Therefore, a deliberate confinement breach is conceivable [24]. Comparison of different Gene Drive Technologies On the basis of these parameters and the aforementioned criteria, the different gene drive techniques can finally be compared. It has to be noted that, gene drives in general fulfill the criterion of high depth of intervention resulting in high technological power and a high range due to persistence. Taking into account the fact that the technology acts on the fundamental basis of 103