Cytochrome b as a useful tool for the identification of blowflies of forensic interest (Diptera, Calliphoridae)

Molecular differentiation of Central European blowfly species (Diptera, Calliphoridae) using mitochondrial and nuclear genetic markers

“…Furthermore, the intraspecific variability also fits this condition, showing, in general, a fewer number of variable positions for the traditional molecular marker. All this is consistent with previous studies, where the widely used COI barcode region was far less discriminatory than other molecular markers, such as COII, NAD6 and Cyt-b [13,15,[40][41][42][43]. Additionally, the COI (616 bp) sequence seems to have a potentially discriminative advantage of performing reliable and unambiguous identification, not only between the species studied here but also between more genetically related species, such as those belonging to Lucilia genus.…”

“…However, for the rest of the species, the Cyt-b (307 bp) and Cyt-btRNA ser -ND1 (495-496 bp) regions seem to be at a disadvantage compared with the rest of the mitochondrial markers, with lower discrimination values. These results do not agree with previous studies [13,19] and may be a result of the lower number of bases studied (approximately 162-351 bp length less) or for the scarce [ ( _ ) T D $ F I G ] [ ( F i g . _ 2 ) T D $ F I G ] Table 2 Pairwise sequence divergence between the studied Calliphoridae (P. regina*, C. vicina*, L. sericata*, L. ampullacea* and L. caesar*) consensus sequences for the COI barcode (658 bp) and COI (616 bp).…”

“…Immature captured specimens were raised until imago emergence and were identified morphologically using specific taxonomic keys [23][24][25][26][27], preserved in 70% ethanol [7] and stored at À20 8C until the time of DNA extraction [13].…”

“…However, morphological differences are subtle, especially in the immature stages and between closely related species [11,12]. These characteristics may be absent in damaged specimens [13,14], though DNA-based identification provides rapid and unambiguous identification in all cases.…”

“…However, it has shown limitations in the identification of some closely related species [12,18]. Recently, other mitochondrial genomic regions have been studied, such as cytochrome b (Cyt-b) and the non-coding region occurring between tRNA ser and NADH dehydrogenase subunit 1 (NAD1) genes, which allow for clear genetic discrimination of Calliphoridae and Oestridae specimens [13,19]. Furthermore, nuclear genetic markers such as the second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA) have been used to identify closely related blowfly species [20,21].…”