关键词: 法医昆虫学, 嗜尸性蝇类, 物种鉴定, 线粒体COI基因, DNA条形码, 北京

Abstract: Sarcosaphagous flies have very important applications in death time estimation and crime scene reconstruction for homicide cases. DNA barcoding technology can extricate the investigators from the difficulty of culturing eggs and larvae of these flies as well as the reliance on special knowledge to scientifically identify the following imagoes, which is of great help for rapid identification of fly samples collected at the crime scene. We collected 77 samples, which belong to 7 dominant species of sarcosaphagous flies in Beijing, from different districts, and sequenced a 1 120 bp region of the mitochondrial cytochrome oxidase subunit I (COI) gene for each individual. Phylogenetic analysis showed that individual sequences of each species highly clustered together with 99% bootstrap support. Sequence divergences within species were less than 1%, while net divergences between species were all greater than 7.74%, the highest reaching 14.85%. Sliding window analysis demonstrated that variable sites for all species were relatively equally distributed along the entire region. By sequencing part of the COI gene, we established the DNA barcodes for the seven dominant species of sarcosaphagous flies in Beijing, which realized the accurate, rapid, and easy identification of these species and provided basic material for the future selection of variable sites that can be used for direct identification of sarcosaphagous flies.

Key words: Forensic entomology, sarcosaphagous flies, species identification, mitochondrial COI gene, DNA barcode, Beijing