Harris County Institute of Forensic Sciences, 1861 Old Spanish Trail, Houston, TX, 77054, USA.
Forensic Sci Med Pathol. 2024 Jun;20(2):412-422. doi: 10.1007/s12024-023-00653-y. Epub 2023 May 24.
Accurate insect identification is critical to the estimation of time of colonization (TOC) and post-mortem interval (PMI) in medicolegal death investigations. DNA testing is advantageous because it enables the identification of immature specimens that may not be identified based on morphology alone. We describe here a simplified DNA barcoding method for identifying relevant species that may be implemented by forensic genetics laboratories. A cytochrome oxidase (COI) fragment is analyzed after PCR amplification with a single primer set. The method is effective for many species commonly encountered in death investigations in the USA: members of blowfly genera Calliphora, Chrysomya, Cochliomyia, Lucilia, and Phormia; members of the flesh fly genera Blaesoxipha, Oxysarcodexia, Ravinia, and Sarcophaga; and the scuttle fly Megaselia scalaris. We tested the method on specimens with verified identifications and used it to build a collection of reference sequences from specimens collected in Harris County, Texas. We show here the correct identification of larvae, pupae, and pupal exuviae from the medicolegal casework.
准确的昆虫鉴定对于法医学死亡调查中的时间推测（TOC）和死后间隔（PMI）的估计至关重要。DNA 测试具有优势，因为它可以识别可能仅凭形态无法识别的未成熟标本。我们在这里描述了一种简化的 DNA 条形码方法，用于鉴定相关物种，法医遗传学实验室可以实施这种方法。通过使用单个引物组进行 PCR 扩增后分析细胞色素氧化酶（COI）片段。该方法在美国的死亡调查中遇到的许多常见物种都很有效：丽蝇属、麻蝇属、丽蝇属、丽蝇属和腐肉蝇属；肉蝇属、Oxysarcodexia、Ravinia 和 Sarcophaga；以及粪蝇 Megaselia scalaris。我们在经过验证鉴定的标本上测试了该方法，并使用它从德克萨斯州哈里斯县收集的标本中构建了一个参考序列集。我们在此展示了法医学案例中幼虫、蛹和蛹蜕的正确鉴定。
