@article {1398, title = {Why is the molecular identification of the forensically important blowfly species Lucilia caesar and L. illustris (family Calliphoridae) so problematic?}, journal = {Forensic Sciences International}, volume = {223}, year = {2012}, month = {11/2012}, pages = {153-159}, chapter = {153}, abstract = {

Species of the fly genus Lucilia are commonly used in forensic investigations to estimate the postmortem interval (PMI). Two close-related species Lucilia caesar and L. illustris are difficult to identify. Previous studies showed that the mitochondrial cytochrome c oxidase subunit I (COI) marker could be used to identify many Lucilia species. However, mixed results were obtained for L. caesar and L. illustris due to some European specimens showing identical haplotypes. Here, we investigated 58 new European male specimens of L. illustris and L. caesar whose morphological identifications were checked and for which COI fragments were sequenced. In addition, two other mitochondrial (cytochrome c oxidase subunit II and 16S) and two nuclear (internal transcribed spacer 2 and 28S ribosomal RNA) markers were obtained for a subset of these samples. For each marker, genetic divergence within each species was in the same range as between species, confirming the close relationship between both species. Moreover, for each of the gene fragments, both species shared at least one haplotype/genotype. Hence, none of the molecular markers tested could be used, alone or in combination, to discriminate between L. illustris and L. caesar.

}, keywords = {16S, 28S, coi, COII, DNA Barcoding, ITS-2, Postmortem interval, Species identification}, url = {http://dx.doi.org/10.1016/j.forsciint.2012.08.020}, author = {Sonet, G.}, editor = {Jordaens, K. and Braet, Y. and Desmyter, S.} } @article {529, title = {Hierarchical analysis of variation in the mitochondrial 16S rRNA gene among Hymenoptera.}, journal = {Molecular biology and evolution}, volume = {15}, year = {1998}, pages = {1728-1743}, abstract = {Nucleotide sequences from a 434-bp region of the 16S rRNA gene were analyzed for 65 taxa of Hymenoptera (ants, bees, wasps, parasitoid wasps, sawflies) to examine the patterns of variation within the gene fragment and the taxonomic levels for which it shows maximum utility in phylogeny estimation. A hierarchical approach was adopted in the study through comparison of levels of sequence variation among taxa at different taxonomic levels. As previously reported for many holometabolous insects, the 16S data reported here for Hymenoptera are highly AT-rich and exhibit strong site-to-site variation in substitution rate. More precise estimates of the shape parameter (alpha) of the gamma distribution and the proportion of invariant sites were obtained in this study by employing a reference phylogeny and utilizing maximum-likelihood estimation. The effectiveness of this approach to recovering expected phylogenies of selected hymenopteran taxa has been tested against the use of maximum parsimony. This study finds that the 16S gene is most informative for phylogenetic analysis at two different levels: among closely related species or populations, and among tribes, subfamilies, and families. Maximization of the phylogenetic signal extracted from the 16S gene at higher taxonomic levels may require consideration of the base composition bias and the site-to-site rate variation in a maximum-likelihood framework.}, keywords = {16S, 16S: genetics, Animals, Base Sequence, DNA, evolution, Genetic Variation, Hymenoptera, Hymenoptera: classification, Hymenoptera: genetics, Mitochondrial, Mitochondrial: chemistry, Mitochondrial: genetics, Molecular, Molecular Sequence Data, Nucleic Acid Conformation, phylogeny, Ribosomal, Ribosomal: chemistry, Ribosomal: genetics, RNA, Wasps, Wasps: classification, Wasps: genetics}, author = {Whitfield, J.B. and Cameron, S.A.} }