Department of Biology, Baylor University, Waco, TX, USA.
Department of Biology, Jigjiga University, Jigjiga, Ethiopia.
Malar J. 2019 Apr 16;18(1):135. doi: 10.1186/s12936-019-2768-0.
The recent finding of a typically non-African Anopheles species in eastern Ethiopia emphasizes the need for detailed species identification and characterization for effective malaria vector surveillance. Molecular approaches increase the accuracy and interoperability of vector surveillance data. To develop effective molecular assays for Anopheles identification, it is important to evaluate different genetic loci for the ability to characterize species and population level variation. Here the utility of the internal transcribed spacer 2 (ITS2) and cytochrome oxidase I (COI) loci for detection of Anopheles species from understudied regions of eastern Ethiopia was investigated.
Adult mosquitoes were collected from the Harewe locality (east) and Meki (east central) Ethiopia. PCR and Sanger sequencing were performed for portions of the ITS2 and COI loci. Both NCBI's Basic Local Alignment Search tool (BLAST) and phylogenetic analysis using a maximum-likelihood approach were performed to identify species of Anopheles specimens.
Two species from the east Ethiopian collection, Anopheles arabiensis and Anopheles pretoriensis were identified. Analyses of ITS2 locus resulted in delineation of both species. In contrast, analysis of COI locus could not be used to delineate An. arabiensis from other taxa in Anopheles gambiae complex, but could distinguish An. pretoriensis sequences from sister taxa.
The lack of clarity from COI sequence analysis highlights potential challenges of species identification within species complexes. These results provide supporting data for the development of molecular assays for delineation of Anopheles in east Ethiopia.
最近在埃塞俄比亚东部发现了一种通常非非洲的疟蚊属物种，这强调了需要进行详细的物种鉴定和特征描述，以进行有效的疟疾媒介监测。分子方法提高了媒介监测数据的准确性和互操作性。为了开发有效的疟蚊属鉴定分子检测方法，评估不同遗传基因座的特征物种和种群水平变异的能力非常重要。本研究评估了内转录间隔区 2（ITS2）和细胞色素氧化酶 I（COI）基因座在检测来自埃塞俄比亚东部未充分研究地区的疟蚊属物种中的效用。
从埃塞俄比亚东部的 Harewe 地区（东部）和 Meki（中东部）采集成年蚊子。对 ITS2 和 COI 基因座的部分区域进行 PCR 和 Sanger 测序。使用 NCBI 的基本局部比对搜索工具（BLAST）和最大似然法进行系统发育分析，以鉴定疟蚊属标本的物种。
从东埃塞俄比亚采集的两种蚊子，即阿比西尼亚疟蚊和普氏疟蚊被鉴定出来。ITS2 基因座的分析导致了两种物种的划分。相比之下，COI 基因座的分析不能用于区分按蚊属冈比亚种复合体中的阿比西尼亚疟蚊，但可以将普氏疟蚊序列与姐妹分类群区分开来。
COI 序列分析缺乏清晰度突出了种间复合体中物种鉴定的潜在挑战。这些结果为在东埃塞俄比亚开发用于划分疟蚊属的分子检测方法提供了支持数据。
