Ander M, Troell K, Chirico J
Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Uppsala, Sweden.
Med Vet Entomol. 2013 Sep;27(3):323-31. doi: 10.1111/j.1365-2915.2012.01050.x. Epub 2012 Oct 29.
Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are insect vectors of economically important veterinary diseases such as African horse sickness virus and bluetongue virus. However, the identification of Culicoides based on morphological features is difficult. The sequencing of mitochondrial cytochrome oxidase subunit I (COI), referred to as DNA barcoding, has been proposed as a tool for rapid identification to species. Hence, a study was undertaken to establish DNA barcodes for all morphologically determined Culicoides species in Swedish collections. In total, 237 specimens of Culicoides representing 37 morphologically distinct species were used. The barcoding generated 37 supported clusters, 31 of which were in agreement with the morphological determination. However, two pairs of closely related species could not be separated using the DNA barcode approach. Moreover, Culicoides obsoletus Meigen and Culicoides newsteadi Austen showed relatively deep intraspecific divergence (more than 10 times the average), which led to the creation of two cryptic species within each of C. obsoletus and C. newsteadi. The use of COI barcodes as a tool for the species identification of biting midges can differentiate 95% of species studied. Identification of some closely related species should employ a less conserved region, such as a ribosomal internal transcribed spacer.
库蠓属（双翅目：蠓科）的吸血蠓是非洲马瘟病毒和蓝舌病病毒等具有重要经济意义的兽医疾病的昆虫传播媒介。然而，基于形态特征对库蠓进行鉴定很困难。线粒体细胞色素氧化酶亚基I（COI）测序，即所谓的DNA条形码技术，已被提议作为一种快速鉴定物种的工具。因此，开展了一项研究，为瑞典馆藏中所有形态学确定的库蠓物种建立DNA条形码。总共使用了代表37个形态学不同物种的237个库蠓标本。条形码分析产生了37个得到支持的聚类，其中31个与形态学鉴定结果一致。然而，使用DNA条形码方法无法区分两对近缘物种。此外，废弃库蠓和纽氏库蠓表现出相对较深的种内差异（超过平均差异的10倍），这导致在废弃库蠓和纽氏库蠓各自内部产生了两个隐存种。使用COI条形码作为吸血蠓物种鉴定工具能够区分95%的研究物种。对于一些近缘物种的鉴定，应该采用保守性较低的区域，如核糖体内部转录间隔区。
