GilArriortua Maite, Saloña-Bordas Marta I, Cainé Laura M, Pinheiro Fátima, M de Pancorbo Marian
Dpto de Zoología y Biología Celular Animal. Facultad de Ciencia y Tecnología. Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain; BIOMICs Research Group. Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Centro de Investigación "Lascaray" Ikergunea, Avda. Miguel de Unamuno 3, 01006 Vitoria-Gasteiz, Spain.
Delegação do Norte do Instituto Nacional de Medicina Legal, Jardim Carrilho Videira, 4050-167 Porto, Portugal; Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-316 Porto, Portugal.
Forensic Sci Int. 2015 Dec;257:393-397. doi: 10.1016/j.forsciint.2015.10.010. Epub 2015 Oct 23.
In forensic entomology, rapid and unambiguous identification of blowfly species is a critical prerequisite for accurately estimating the post-mortem interval (PMI). The conventional diagnosis of cadaveric entomofauna based on external characters is hampered by the morphological similarities between species, especially in immature stages. Genetic analysis has been shown to allow precise and reliable diagnosis and delimitation of insect species. Nevertheless, the taxonomy of some species remains unresolved. This study was focused on improving the effectiveness and accuracy of analysis based on the widely used cytochrome c oxidase subunit I barcode region (COI barcode, 658 bp), complemented by other mitochondrial and nuclear regions, such as cytochrome b (Cyt-b, 307 bp) and the second internal transcribed spacer (ITS2, 310-331 bp), for the identification of Southern European blowflies. We analyzed a total of 209 specimens, collected from 38 human corpses, belonging to three Calliphoridae genera and seven species: Chrysomya (Ch. albiceps), Calliphora (C. vicina and C. vomitoria), and Lucilia (L. sericata, L. ampullacea, L. caesar and L. illustris). These species are the most common PMI indicators in Portugal. The results revealed that unambiguous separation of species of the Lucilia genus requires different loci from the barcode region. Furthermore, we conclude that the ITS2 (310-331 bp) molecular marker is a promising diagnostic tool because its inter-specific discriminatory power enables unequivocal and consistent distinctions to be made, even between closely related species (L. caesar-L. illustris). This work also contributes new genetic data that may be of interest in performing species diagnosis for Southern European blowflies. Notably, to the best of our knowledge, we provide the first records of the Cyt-b (307 bp) locus for L. illustris and the ITS2 (310-331 bp) region for Iberian Peninsula Lucilia species.
在法医昆虫学中，快速且明确地鉴定丽蝇种类是准确估计死后间隔时间（PMI）的关键前提。基于外部特征对尸体昆虫群落进行传统诊断，会受到物种间形态相似性的阻碍，尤其是在幼虫阶段。遗传分析已被证明能够实现对昆虫物种的精确且可靠的诊断和界定。然而，一些物种的分类学问题仍未解决。本研究聚焦于提高基于广泛使用的细胞色素c氧化酶亚基I条形码区域（COI条形码，658 bp）分析的有效性和准确性，并辅以其他线粒体和核区域，如细胞色素b（Cyt-b，307 bp）和第二内部转录间隔区（ITS2，310 - 331 bp），用于鉴定南欧丽蝇。我们总共分析了209个标本，这些标本采集自38具人类尸体，分属于丽蝇科的三个属和七个物种：金蝇属（Ch. albiceps）、绿蝇属（C. vicina和C. vomitoria）以及卢蝇属（L. sericata、L. ampullacea、L. caesar和L. illustris）。这些物种是葡萄牙最常见的PMI指示物种。结果表明，明确区分卢蝇属的物种需要条形码区域以外的不同基因座。此外，我们得出结论，ITS2（310 - 331 bp）分子标记是一种很有前景的诊断工具，因为其种间鉴别能力能够实现明确且一致的区分，即使是在亲缘关系密切的物种（L. caesar - L. illustris）之间。这项工作还提供了新的遗传数据，这些数据可能对南欧丽蝇的物种诊断具有重要意义。值得注意的是，据我们所知，我们首次记录了L. illustris的Cyt-b（307 bp）基因座以及伊比利亚半岛卢蝇属物种的ITS2（310 - 331 bp）区域。
