Grigoraki Linda, Pipini Dimitra, Labbé Pierrick, Chaskopoulou Alexandra, Weill Mylene, Vontas John
Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece.
Department of Biology, University of Crete, Heraklion, Greece.
PLoS Negl Trop Dis. 2017 Apr 10;11(4):e0005533. doi: 10.1371/journal.pntd.0005533. eCollection 2017 Apr.
Aedes albopictus is one of the most invasive human disease vectors. Its control has been largely based on insecticides, such as the larvicide temephos. Temephos resistance has been associated with the up-regulation, through gene amplification, of two carboxylesterase (CCE) genes closely linked on the genome, capable of sequestering and metabolizing temephos oxon, the activated form of temephos.
Here, we investigated the occurrence, geographical distribution and origin of the CCE amplicon in Ae. albopictus populations from several geographical regions worldwide. The haplotypic diversity at the CCEae3a locus revealed high polymorphism, while phylogenetic analysis showed an absence of correlation between haplotype similarity and geographic origin. Two types of esterase amplifications were found, in two locations only (Athens and Florida): one, previously described, results in the amplification of both CCEae3a and CCEae6a; the second is being described for the first time and results in the amplification of CCEae3a only. The two amplification events are independent, as confirmed by sequence analysis. All individuals from Athens and Florida carrying the CCEae3a-CCEae6a co-amplicon share a common haplotype, indicating a single amplification event, which spread between the two countries.
The importance of passive transportation of disease vectors, including individuals carrying resistance mechanisms, is discussed in the light of efficient and sustainable vector control strategies.
白纹伊蚊是最具入侵性的人类疾病传播媒介之一。其控制主要基于杀虫剂，如杀幼虫剂双硫磷。双硫磷抗性与通过基因扩增上调基因组上紧密相连的两个羧酸酯酶（CCE）基因有关，这两个基因能够隔离和代谢双硫磷的活化形式——双硫磷氧。
在此，我们调查了全球多个地理区域的白纹伊蚊种群中CCE扩增子的发生情况、地理分布和起源。CCEae3a位点的单倍型多样性显示出高度多态性，而系统发育分析表明单倍型相似性与地理起源之间不存在相关性。仅在两个地点（雅典和佛罗里达）发现了两种类型的酯酶扩增：一种是先前描述的，导致CCEae3a和CCEae6a均扩增；第二种是首次描述的，仅导致CCEae3a扩增。序列分析证实这两个扩增事件是独立的。雅典和佛罗里达所有携带CCEae3a - CCEae6a共扩增子的个体共享一个共同单倍型，表明是单一扩增事件，该事件在两国之间传播。
根据高效且可持续的病媒控制策略，讨论了包括携带抗性机制个体在内的病媒被动运输的重要性。
