The availability of 16SrDNA gene for identifying forensically important blowflies in China

Abstract

Different species of sarcosaphagous insects are found on human corpses at different phases after death, which is important for the estimation of postmortem interval (PMI) and other questions of forensic relevance. Calliphoridae are one of the earliest visitors to infest a corpse and lay their eggs, and develop maggots. Following the conventional method by morphology, a molecular method is a necessary assistance of species identification. This study has investigated the applicability of sequencing of mitochondrial DNA (mtDNA) based on a 250 base pair region of the gene for 16S rDNA to identify the forensically important species of Calliphoridae which were collected from 10 sites distributed at 9 provinces in China, including 25 specimens (8 species) in 3 genera of Calliphoridae family, including some specimens of Chrysomya megacephala (Fabricius), Chrysomya rufifacies (Macquart), Calliphora vicina (Robineau-Desvoidy), Lucilia caesar (Linnaeus), Lucilia porphyrina (Walker), Lucilia sericate (Meigen), Lucilia bazini (Seguy), Lucilia illustris (Meigen). The analysis of 16S rDNA sequences revealed abundant phylogenetically informative nucleotide substitutions that could identify Calliphoridae to species group. It renders the reliable identification of important sarcosaphagous insects in China, particularly in case of murder or suspicious death by providing an estimate of post-mortem interval (PMI) and scene of crime.