DNA barcoding and the differentiation between North American and West European Phormia regina (Diptera,Calliphoridae, Chrysomyinae).

Kurt Jordaens,Marc De Meyer,Stijn Desmyter,Yves Braet,Frankie Goovaerts,Thierry Backeljau,Luc Bourguignon,Gontran Sonet

doi:10.3897/zookeys.365.6202

Abstract

Phormia regina (the black fly) is a common Holarctic blow fly species which serves as a primary indicator taxon to estimate minimal post mortem intervals. It is also a major research model in physiological and neurological studies on insect feeding. Previous studies have shown a sequence divergence of up to 4.3% in the mitochondrial COI gene between W European and N American P. regina populations. Here, we DNA barcoded P. regina specimens from six N American and 17 W European populations and confirmed a mean sequence divergence of ca. 4% between the populations of the two continents, while sequence divergence within each continent was a ten-fold lower. Comparable mean mtDNA sequence divergences were observed for COII (3.7%) and cyt b (5.3%), but mean divergence was lower for 16S (0.4–0.6%). Intercontinental divergence at nuclear DNA was very low (≤ 0.1% for both 28S and ITS2), and we did not detect any morphological differentiation between N American and W European specimens. Therefore, we consider the strong differentiation at COI, COII and cyt b as intraspecific mtDNA sequence divergence that should be taken into account when using P. regina in forensic casework or experimental research.

Highlights

Forensic entomology uses the larval and pupal developmental stages of insects sampled on a corpse to estimate a minimum post-mortem interval (PMImin) of the corpse (Amendt et al 2004, 2007)
Comparable mean mtDNA sequence divergences were observed for COII (3.7%) and cytb (5.3%), but mean divergence was lower for 16S (0.4–0.6%)
We did not detect morphological differences between N American and W European P. regina specimens in the 11 external color characters that we scored (Table 2)

Summary

Introduction

Forensic entomology uses the larval and pupal developmental stages of insects sampled on a corpse to estimate a minimum post-mortem interval (PMImin) of the corpse (Amendt et al 2004, 2007). This requires i) detailed and accurate knowledge of the developmental rate of the species of forensic interest under different temperature conditions (Charabidze 2012), and ii) identification tools by which the different immature insect stadia can be identified (Catts 1992). To improve the success and reliability of identifications, a number of molecular techniques and tools have been explored to identify forensically important species (Wells and Stevens 2008, reviewed in Jordaens et al in press)

Methods

Results

Conclusion