Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham 44150 Thailand.
Trop Biomed. 2023 Sep 1;40(3):363-369. doi: 10.47665/tb.40.3.014.
The biting midge Culicoides peregrinus Kieffer is a significant pest and vector species, and knowledge of its genetic diversity and genetic structure is critically important for designing an effective control program. However, such information is limited to only small sample-size DNA barcoding studies. Therefore, in this study, we used mitochondrial cytochrome c oxidase I (COI) to examine genetic structure and diversity of C. peregrinus from northeastern Thailand. In addition, we also inferred genetic relationships between C. peregrinus from Thailand and those reported from other countries across the geographic range of the species. Maximum intraspecific genetic divergence (3.83%) within Thai specimens was relatively high compared to other Culicoides species. Genetic structure analysis revealed that 71% (32 from 45) of population comparisons were highly significantly different. A high level of genetic structure among populations, even between those in close geographic proximity (22 km geographic distance) suggested that there has been little or no movement between local populations. This is possibly due to the ability to exploit diverse types of breeding site and a generalist feeding habit which enables C. peregrinus to complete its life cycle within cattle pens. Genetic relationships between Thai C. peregrinus and those reported from other countries revealed three genetically divergent lineages (A, B and C) associated with geographic origins. Specimens from Thailand + China formed lineage A, those from Australia formed lineage B and India + Bangladesh belonged to lineage C. These genetically divergent lineages also agree with morphological variation of the wing pale marking spots. Further investigation using independent genetic loci from nuclear genes will be very useful to resolve taxonomic status of these divergent lineages.
刺扰伊蚊是一种重要的害虫和病媒种，了解其遗传多样性和遗传结构对于设计有效的控制计划至关重要。然而，这些信息仅限于小规模的 DNA 条形码研究。因此，在这项研究中，我们使用线粒体细胞色素 c 氧化酶 I（COI）来研究来自泰国东北部的刺扰伊蚊的遗传结构和多样性。此外，我们还推断了泰国的刺扰伊蚊与该物种在地理分布范围内来自其他国家的报道之间的遗传关系。与其他伊蚊种相比，泰国标本的最大种内遗传分歧（3.83%）相对较高。遗传结构分析表明，71%（32 个来自 45 个）的种群比较存在高度显著差异。种群之间存在高水平的遗传结构，即使在地理上接近的种群（22 公里的地理距离）之间也是如此，这表明当地种群之间的迁徙很少或没有。这可能是由于其能够利用多种类型的繁殖地和通用的摄食习性，使刺扰伊蚊能够在牛舍内完成其生命周期。泰国刺扰伊蚊与来自其他国家的报道之间的遗传关系显示出与地理起源相关的三个遗传分化谱系（A、B 和 C）。来自泰国+中国的标本形成谱系 A，来自澳大利亚的标本形成谱系 B，来自印度+孟加拉国的标本属于谱系 C。这些遗传分化谱系也与翅膀苍白标记斑点的形态变异一致。使用来自核基因的独立遗传基因座的进一步研究将非常有助于解决这些分化谱系的分类地位问题。
