Identification of the forensically important flies (Diptera: Muscidae) based on cytochrome oxidase subunit I (COI) gene in China

Accurate species identification is a crucial step in forensic entomology, as the insect collected on a corpse can provide useful information for estimation of postmortem interval (PMI). However, morphological distinction may on occasion be impossible to the adult flies and nymphs of the same genus. DNA-based method can be used as a supplemental means of morphological method. In this study, 31 forensically important Muscidae flies were collected from 15 locations in 11 provinces of China, and a 272 base pair region of the mitochondrial cytochrome oxidase subunit I (COI) gene was sequenced. The monophyletic branches of the phylogenetic tree revealed that this marker is suitable for discrimination between these five species of four genera of Muscidae. The genetic variations found on COI can be applied not only to identify the forensically important species, but also to understand the taxonomic positions of the sarcophagine species. In addition, this research will be instrumental for implementation of the Chinese Muscidae database.