Objective To solve the problem of morphological identification of Sarcosaphagous flies and to provide technical supports for estimating the postmortem interval (PMI) in forensic practice, the forensically important species of Sarcosaphagous flies were identified through testing a 278 base pairs region of the mitochondrial cytochrome oxidase I (COI) gene. Methods Eighteen fly specimens, including five species of three genera, were collected from the corpses of rabbits from 15 different areas of China. The mtDNA of flies was extracted for PCR amplification. Their COI sequences were determined by sequencing and uploaded to GENBANK. The sequence alignment was carried out by DNAMAN4. 0. A evolutionary divergence and a neighbor - joining tree were constructed using MEGA4.0. 2 package. Results It was showed that intraspecific and interspecific variation ranged from 0% to 0. 8% and 7. 6% to 13. 4% , respectively. In the interspecies level, Bootstrap test reliability range fom 31% to 56% respectively. In the intraspecies level, Bootstrap test reliability was 100% except in musca domestica and ophyra spinigera. Conclusion The 278 bp region of the mitochondrial COI gene of sarcosaphagous flies can be effectively used to distinguish their common species, and combining with morphological features, it allows accurate identification of Sarcosaphagous fly species.%目的 检测嗜尸性蝇类线粒体DNA(mtDNA)细胞色素氧化酶辅酶Ⅰ(COI)中278bp序列,鉴定蝇科3属5种嗜尸性蝇,解决其形态学种类鉴定的难题,为死亡时间推断提供技术支持.方法 从15省、市(地区)室外草地家兔尸体上采集蝇科3属5种共计18个蝇类成蝇样本,提取mtDNA进行PCR扩增,序列测定且上传GENBANK,并使用MEGA软件进行序列比对及进化距离分析,构建不同地区各种内和种间系统发育树,尝试区分常见嗜尸性蝇类.结果 基因序列分析结果显示,上述蝇类mtDNA上COI基因序列的种内进化分歧均数在0％～0.8％,种间进化分歧均数在7.6％～13.4％之间；进化距离分析显示,在种间水平,家蝇和孕幼家蝇、斑趾黑蝇和家蝇、厩螫蝇和厚环黑蝇Bootstrap检验的可信度分别为56％、31％、53％；种内水平除了家蝇和厚环黑蝇外,其他Bootstrap检验可信度均为100％.结论 嗜尸性蝇类mtDNA中COI序列分析能够区分常见嗜尸性蝇类,作为形态学方法的补充手段,实现精确的蝇种鉴定.
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