Dept. of Medical and Molecular Genetics, Indiana University School of Medicine, 1234 Notre Dame Avenue, South Bend, IN, 46530, USA.
The University of Notre Dame, Eck Institute for Global Health, Notre Dame, IN, 46556, USA.
Malar J. 2017 Nov 13;16(1):461. doi: 10.1186/s12936-017-2112-5.
Although larviciding can reduce the number of outdoor biting malaria vector mosquitoes, which may help to prevent residual malaria transmission, the current larvicide repertoire is faced with great challenges to sustainability. The identification of new effective, economical, and biorational larvicides could facilitate maintenance and expansion of the practice of larviciding in integrated malaria vector mosquito control programmes. Interfering RNA molecules represent a novel class of larvicides with untapped potential for sustainable mosquito control. This investigation tested the hypothesis that short interfering RNA molecules can be used as mosquito larvicides.
A small interfering RNA (siRNA) screen for larval lethal genes identified siRNAs corresponding to the Anopheles gambiae suppressor of actin (Sac1), leukocyte receptor complex member (lrc), and offtrack (otk) genes. Saccharomyces cerevisiae (baker's yeast) was engineered to produce short hairpin RNAs (shRNAs) for silencing of these genes. Feeding larvae with the engineered yeasts resulted in silenced target gene expression, a severe loss of neural synapses in the larval brain, and high levels of larval mortality. The larvicidal activities of yeast interfering RNA larvicides were retained following heat inactivation and drying of the yeast into user-friendly tablet formulations that induced up to 100% larval mortality in laboratory trials.
Ready-to-use dried inactivated yeast interfering RNA larvicide tablets may someday be an effective and inexpensive addition to malaria mosquito control programmes and a valuable, biorational tool for addressing residual malaria transmission.
虽然杀幼虫剂可以减少户外叮咬疟疾传播媒介蚊子的数量，这可能有助于防止残留疟疾传播，但当前的杀幼虫剂系列面临着可持续性的巨大挑战。鉴定新的有效、经济和基于生物学的杀幼虫剂可以促进在综合疟疾病媒蚊控制规划中维持和扩大杀幼虫剂的使用。干扰 RNA 分子代表了一类新的杀幼虫剂，具有可持续控制蚊子的未开发潜力。本研究检验了这样一个假设，即短干扰 RNA 分子可用作蚊虫幼虫的杀幼虫剂。
用于幼虫致死基因的小干扰 RNA (siRNA) 筛选鉴定了与冈比亚按蚊抑制肌动蛋白（Sac1）、白细胞受体复合物成员（lrc）和偏离轨道（otk）基因对应的 siRNA。酿酒酵母（面包酵母）被工程改造以产生这些基因的短发夹 RNA (shRNA) 进行沉默。用工程酵母喂养幼虫会导致靶基因沉默、幼虫大脑中的神经突触严重丧失以及高死亡率。酵母干扰 RNA 杀幼虫剂的杀幼虫活性在酵母的热失活和干燥后仍保留，干燥后酵母制成用户友好的片剂制剂，在实验室试验中诱导高达 100%的幼虫死亡率。
即用型干燥失活酵母干扰 RNA 杀幼虫剂片剂将来可能成为疟疾病媒蚊控制规划中的一种有效且廉价的补充，也是解决残留疟疾传播的有价值的基于生物学的工具。
