Utility of GenBank and the Barcode of Life Data Systems (BOLD) for the identification of forensically important Diptera from Belgium and France

Stijn Desmyter,Thierry Backeljau,Luc Bourguignon,Marc de Meyer,Yves Braet,Erena Dupont,Kurt Jordaens,Gontran Sonet

doi:10.3897/zookeys.365.6027

Abstract

Fly larvae living on dead corpses can be used to estimate post-mortem intervals. The identification of these flies is decisive in forensic casework and can be facilitated by using DNA barcodes provided that a representative and comprehensive reference library of DNA barcodes is available.We constructed a local (Belgium and France) reference library of 85 sequences of the COI DNA barcode fragment (mitochondrial cytochrome c oxidase subunit I gene), from 16 fly species of forensic interest (Calliphoridae, Muscidae, Fanniidae). This library was then used to evaluate the ability of two public libraries (GenBank and the Barcode of Life Data Systems – BOLD) to identify specimens from Belgian and French forensic cases. The public libraries indeed allow a correct identification of most specimens. Yet, some of the identifications remain ambiguous and some forensically important fly species are not, or insufficiently, represented in the reference libraries. Several search options offered by GenBank and BOLD can be used to further improve the identifications obtained from both libraries using DNA barcodes.

Highlights

Insects collected on crime scenes can be used to estimate the time elapsed between death and corpse discovery, i.e. the post mortem interval or PMI (Rodriguez and Bass 1983, Joseph et al 2011, Charabidze 2012)
We constructed a local (Belgium and France) reference library of 85 sequences of the COI DNA barcode fragment, from 16 fly species of forensic interest (Calliphoridae, Muscidae, Fanniidae). This library was used to evaluate the ability of two public libraries (GenBank and the Barcode of Life Data Systems – BOLD) to identify specimens from Belgian and French forensic cases
Several search options offered by GenBank and BOLD can be used to further improve the identifications obtained from both libraries using DNA barcodes

Summary

Introduction

Insects collected on crime scenes can be used to estimate the time elapsed between death and corpse discovery, i.e. the post mortem interval or PMI (Rodriguez and Bass 1983, Joseph et al 2011, Charabidze 2012). Mazzanti et al 2010) or specimens of morphologically similar species Meiklejohn et al 2011, Jordaens et al 2012) This technique relies on the comparison of a query sequence obtained from a sample collected at a crime scene with a library of reference sequences from well-identified specimens. The reference sequence showing the highest sequence similarity (= best match) with the query sequence can be used for its identification. The validity of this approach depends on the reference library, which has to be representative, comprehensive and without misidentification or sequencing error (Wells and Stevens 2008)

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Discussion

Conclusion