Loss of cytoplasmic incompatibility in < i > Wolbachia < /i > -infected < i > Aedes aegypti < /i > under field conditions

by Perran A. Ross, Scott A. Ritchie, Jason K. Axford, Ary A. HoffmannWolbachia bacteria are now being introduced intoAedes aegypti mosquito populations for dengue control. WhenWolbachia infections are at a high frequency, they influence the local transmission of dengue by direct virus blocking as well as deleterious effects on vector mosquito populations. However, the effectiveness of this strategy could be influenced by environmental temperatures that decreaseWolbachia density, thereby reducing the ability ofWolbachia to invade and persist in the population and block viruses. We rearedwMel-infectedAe.aegypti larvae in the field during the wet season in Cairns, North Queensland. Containers placed in the shade produced mosquitoes with a highWolbachia density and little impact on cytoplasmic incompatibility. However, in 50% shade where temperatures reached 39 °C during the day,wMel-infected males partially lost their ability to induce cytoplasmic incompatibility and females had greatly reduced egg hatch when crossed to infected males. In a second experiment under somewhat hotter conditions (>40 °C in 50% shade), field-rearedwMel-infected females had their egg hatch reduced to 25% when crossed to field-rearedwMel-infected males.Wolbachia density was reduced in 50% shade for both sexes in both experiments, with some mosquitoes cleared of theirWolbachia infections entirely. To investigate the critical temperature range for the loss ofWolbachia infections, we heldAe.aegypti eggs ...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research