Identification of Forensically Important Flesh Flies Using the Cytochrome C Oxidase Subunits I and II Genes

Abstract

Forensically important flesh flies (Diptera: Sarcophagidae) often are not morphologically distinguishable, especially at the immature stage. In addition, female flies are quite similar in general morphology, making accurate identifications difficult. DNA-based technologies, particularly mitochondrial DNA (mtDNA), have been used for species-level identification. The cytochrome oxidase subunits I and II (COI-COII) sequences of Iranian Sarcophagidae are still unavailable in GenBank. In this study as many as 648 (540 males and 106 females) fly specimens from family Sarcophagidae, representing 10 sarcophagid species, including eight forensically important species were collected from seven locations in five Iranian provinces. Of these, 150 male specimens were identified based on both morphology of male genitalia and DNA sequencing analysis. Sequence data from the COI-COII regions for 10 flesh fly species collected in Iran were generated for the first time. Digestion of COI-COII region by restriction enzymes RsaI, EcoRV, and HinfI provided distinct restriction fragment length polymorphism profiles among the species and can serve as molecular markers for species determination. Phylogenetic analysis represented that the COI-COII sequences are helpful for delimitation of sarcophagid species and implementation in forensic entomology. However, the application of the COI-COII fragment as a species identifier requires great caution and additional species and markers should be studied to ensure accurate species identification in the future.

Keywords: Iran; PCR; RFLP; Sarcophagidae; molecular marker.