Zhao Siyu, Liu Hongkai, Wu Yiming, Wu Peilin, Fu Junyu, Yang Huijuan, James Anthony A, Chen Xiao-Guang
Department of Pathogen Biology, Institute of Tropical Medicine, School of Public Health, Southern Medical University, Guangzhou, China.
Department of Microbiology & Molecular Genetics, University of California, Irvine, CA, USA.
Insect Sci. 2024 Aug 12. doi: 10.1111/1744-7917.13430.
Aedes albopictus is an important vector of arboviruses and prefers small containers of stagnant water as oviposition sites. One of the mechanisms mosquitoes use to search for suitable oviposition sites is relying on odor cues from prospective sites and their surroundings. The genetic and molecular bases of this behavior are not known for Ae. albopictus. Oviposition site-searching behavior can be separated into 2 stages: container location and water detection. We applied a glue compound to the antennae and the maxillary palps of adult females to mask their ability to detect molecules that may guide them to preferred oviposition sites. Treatment of the antennae significantly reduces the location index (P < 0.001), indicating a decreased ability to find oviposition sites, whereas no significant difference was observed in mosquitoes with maxillary palps treated with the same glue compound (P > 0.05). The detection time, measured as the duration from contact with the water surface to the deposition of the first egg, was extended in mosquitoes with treated antennae or maxillary palps, supporting the conclusion that olfaction is involved in the detection of oviposition site. Transcriptomic analysis identified differentially expressed olfactory-related genes, including obp67, obp56d-like, obp19d-like and obp67-like. RNA interference (RNAi)-mediated knockdown of obp67 and obp56d-like significantly affected the location index and detection time, respectively. Cas9/guide RNA-mediated knockout of obp56d-like resulted in a prolonged detection time, compared with the wild type (P < 0.05). These findings help to elucidate aspects of the olfactory mechanisms involved in Ae. albopictus oviposition site selection, and provide a basis for the development of mosquito surveillance and control strategies.
白纹伊蚊是虫媒病毒的重要传播媒介,偏好将小容器中的积水作为产卵场所。蚊子用于寻找合适产卵场所的机制之一是依靠来自潜在场所及其周围环境的气味线索。对于白纹伊蚊而言,这种行为的遗传和分子基础尚不清楚。产卵场所搜索行为可分为两个阶段:容器定位和水体检测。我们在成年雌性蚊子的触角和下颚须上涂抹了一种胶水化合物,以掩盖它们检测可能引导它们前往偏好产卵场所的分子的能力。对触角进行处理显著降低了定位指数(P < 0.001),表明寻找产卵场所的能力下降,而用相同胶水化合物处理下颚须的蚊子未观察到显著差异(P > 0.05)。以从接触水面到产下第一枚卵的持续时间来衡量的检测时间,在用处理过触角或下颚须的蚊子中延长了,这支持了嗅觉参与产卵场所检测的结论。转录组分析确定了差异表达的嗅觉相关基因,包括obp67、obp56d-like、obp19d-like和obp67-like。RNA干扰(RNAi)介导的obp67和obp56d-like基因敲低分别显著影响了定位指数和检测时间。与野生型相比,Cas9/引导RNA介导的obp56d-like基因敲除导致检测时间延长(P < 0.05)。这些发现有助于阐明白纹伊蚊产卵场所选择所涉及的嗅觉机制的各个方面,并为蚊虫监测和控制策略的制定提供依据。