Exploratory Study on DNA Barcode Combined with PCR-HRM Technology for Rapid and Accurate Identification of Necrophilous Fly Species.

Molecular species identification plays an increasingly important role in forensic entomology and is centered on selecting appropriate DNA barcodes, which there are not yet enough of. Such identification is decisive in discovering a better DNA barcode for the identification of necrophilous fly species. Here, we analyzed 10 common necrophilous fly species found on Hainan Island; designed 12 pairs of fly-specific primers from different mitochondrial regions; screened two fly DNA barcodes with better results than those of published studies, which were used as controls; and employed a high-resolution melting (HRM) curve to construct PCR-HRM technology systems for rapid and efficient necrophilous fly species identification. The results showed that, among the 14 DNA barcoding PCR-HRM systems, the newly designed COXII-519/COXII-615 primer was the best, which identified 10 necrophilous fly species in one test. The second-best system was the C1-J-2495/C1-N-2800 primer published in the literature, which identified six fly species in one test. Moreover, since the COXII-519/COXII-615 primer system performed successfully in both stale (stored over two years) and larval samples due to its short amplificated fragment (shorter than 97 bp), it may serve as a new efficient DNA barcode for necrophilic fly species identification. The new DNA barcoding PCR-HRM system established in this study enables the rapid and accurate identification of necrophilic fly species.