![]() ![]() gambiae, where gene drive transgenes targeting female fertility genes spread for a few generations. The potential of gene drives to induce sterility in field populations has been recently demonstrated in cages of An. Among the most promising strategies, gene drives are in development for Anopheles which could spread infertility through natural mosquito populations by positively biasing their own inheritance. To circumvent the potential problems linked to sterility by irradiation or chemosterilants, strategies based on genetic manipulation of insect fertility are being considered. Adapting SIT and other similar sterilizing technologies (such as chemosterilization) to Anopheles vectors of human malaria has been challenging, and requires optimization to maximize competitiveness of colonized, mass-reared and sterilized males. Sterile Insect Technique (SIT), a strategy based on the mass release of irradiated males to sterilize females upon mating, has been successfully implemented against populations of the screwworm Cochliomyia hominivorax and the Mediterranean fruit fly Ceratitis capitata to reduce the economic burden of these important agricultural pests. Targeting fertility for insect control has been successful in a variety of species, and a number of strategies aimed at inducing sterility in field populations are currently being developed in mosquitoes. Alarmingly, populations have emerged with resistance to all four classes of insecticides available for malaria control, making the development of novel vector control technologies increasingly urgent. For example, the majority of anophelines across Africa are now resistant to pyrethroids, the only insecticide approved for use on LLINs, while resistance rates to carbamates and organophosphates are on the rise. Although control methods based on the use of long-lasting insecticide-treated nets (LLINs) and indoor residual sprays (IRS) have been very effective at reducing the number of malaria cases and deaths in the past 15 years, increasing levels of insecticide resistance in Anopheles populations throughout Africa are threatening the use of these strategies. The Plasmodium parasites that cause this devastating disease are transmitted to humans exclusively by anopheline mosquitoes. Malaria kills approximately 450,000 people every year, mostly children in sub-Saharan Africa, and infects hundreds of millions more. This provides a valuable tool for the assessment of male mating competitiveness not only in laboratory experiments but also in semi-field and field studies aimed at testing the feasibility of releasing genetically modified mosquitoes for disease control. gambiae facilitates the live detection of successful insemination hours after copulation has occurred. The validation of the first MAG-specific promoter in transgenic An. PluTo males were equally as competitive at mating as wild type males, and females mated to these males did not show any reduction in reproductive fitness. Moreover, the fusion protein was integrated into the mating plug and transferred to the female atrium during mating where it could be visualized microscopically in vivo without sacrificing the female. Anopheles gambiae PluTo transgenic males showed strong red fluorescence specifically in the MAGs and with a pattern closely matching endogenous Plugin expression. We used the promoter region of the major mating plug protein, Plugin, to control the expression of a Plugin-tdTomato (PluTo) fusion protein, hypothesizing that this fusion protein could be incorporated into the plug for sexual transfer to the female. Here we exploit this male reproductive feature and validate the use of a MAG-specific promoter to fluorescently label the mating plug and visualize the occurrence of insemination in vivo. ![]() gambiae males transfer their male accessory glands (MAGs) seminal secretions as a coagulated mating plug which is deposited in the female atrium. Interestingly, unlike other insects, during mating An. These strategies rely on the mating competitiveness of release males, however currently there is no method to determine male mating success without sacrificing the female. Given the increasing rates of insecticide resistance in these mosquitoes, alternative control strategies based on the release of genetically modified males are being evaluated to stop transmission by these disease vectors. The most important malaria vectors in sub-Saharan Africa are mosquitoes of the Anopheles gambiae complex including An. ![]() Malaria parasites, transmitted by the bite of an anopheline mosquito, pose an immense public health burden on many tropical and subtropical regions. ![]()
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