Das Projekt "Malaria risk resulting from urban agriculture - persisting misconception or urgent need for mitigation? - GIS-supported spatial analysis in Dar es Salaam (Tanzania)" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Institut für Umweltsozialwissenschaften und Geographie, Professur für Physische Geographie durchgeführt. Urban agriculture is a common livelihood strategy for residents of cities in developing countries. In Dar es Salaam, urban agriculture comprises the production of crops, livestock and vegetables. Malaria transmission in Dar es Salaam is a significant problem and assumed to be closely linked to agricultural activities, where farmers and mosquitoes share common water resources. Although urban agriculture often provides breeding sites for malaria vectors, it is not clear if this increases actual malaria transmission in the surrounding areas.
Das Projekt "Development and risk assessment of transgenic environmentally-friendly insect pest control methods for fruit flies and mosquitoes" wird vom Umweltbundesamt gefördert und von Universität Gießen, Institut für Phytopathologie und Angewandte Zoologie, Abteilung Angewandte Entomologie durchgeführt. Various species of pest insects cause substantial damage to agriculture every year, or transmit deadly diseases to animals and humans. A successful strategy to control pest insect populations is based on the Sterile Insect Technique (SIT), which uses the release of mass-reared, radiation sterilized male insects to cause infertile matings and thus reduce the pest population level. However, irradiation is not applicable to every insect species. Thus, new strategies based on genetic modifications of pest insects have been developed or are currently under investigation.The goal of the proposed research is to improve the development and ecological safety of genetically engineered (GE) insects created for enhanced biological control programs, including the SIT and new strategies based on conditional lethality. A major concern for GE insect release programs is transgene stability, and maintenance of their consistent expression. Transgene loss or intra-genomic movement could result in loss of strain attributes, and may ultimately lead to interspecies movement resulting in ecological risks. To address potential transgene instability, a new transposon vector that allows post-integration immobilization will be tested in the Mediterranean, Mexican and Oriental fruit fly tephritid pest species. In addition, the system will be established in the mosquito species Aedes and Anopheles - carriers of dengue and malaria.Random genomic insertion is also problematic for GE strain development due to genomic position effects that suppress transgene expression, and insertional mutations that negatively affect host fitness and viability. Diminished transgene expression could result in the unintended survival of conditional lethal individuals, or the inability to identify them. To target transgene vectors to defined genomic insertion sites having minimal negative effects on gene expression and host fitness, a recombinase-mediated cassette exchange (RMCE) strategy will be developed that. RMCE will also allow for stabilization of the target site, will be tested in tephritid and mosquito species, and will aid to the development of stabilized target-site strains for conditional lethal biocontrol. This will include a molecular and organismal evaluation of an RNAi-based lethality approach. Lethality based on an RNAi mechanism in the proposed insects would increase the species specificity and having multiple targets for lethality versus one target in existing systems. By seeking to improve transgene expressivity and stabilization of transposon-based vector systems, this proposal specifically addresses issues related to new GE insects by reducing their unintended spread after field release, and by limiting the possibilities for transgene introgression.