Europe Butterfly Fauna Reveals High Performance for Temperate
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Downloaded from rspb.royalsocietypublishing.org on August 12, 2010 Complete DNA barcode reference library for a country's butterfly fauna reveals high performance for temperate Europe Vlad Dinca, Evgeny V. Zakharov, Paul D. N. Hebert and Roger Vila Proc. R. Soc. B published online 11 August 2010 doi: 10.1098/rspb.2010.1089 Supplementary data "Data Supplement" http://rspb.royalsocietypublishing.org/content/suppl/2010/08/10/rspb.2010.1089.DC1.h tml References This article cites 53 articles, 16 of which can be accessed free http://rspb.royalsocietypublishing.org/content/early/2010/08/10/rspb.2010.1089.full.ht ml#ref-list-1 P<P Published online 11 August 2010 in advance of the print journal. 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B doi:10.1098/rspb.2010.1089 Published online Complete DNA barcode reference library for a country’s butterfly fauna reveals high performance for temperate Europe Vlad Dinca˘ 1,2, Evgeny V. Zakharov3, Paul D. N. Hebert3 and Roger Vila1,4,* 1Institute of Evolutionary Biology (UPF-CSIC), Passeig Marı´tim de la Barceloneta 37-49, 08003 Barcelona, Spain 2Departament de Gene`tica i Microbiologia, Universitat Auto`noma de Barcelona, 08193 Bellaterra (Barcelona), Spain 3Biodiversity Institute of Ontario, University of Guelph, Guelph, Ontario, Canada N1G 2W1 4Institucio´ Catalana de Recerca i Estudis Avanc¸ats (ICREA), Passeig Lluı´s Companys 23, 08010 Barcelona, Spain DNA barcoding aims to accelerate species identification and discovery, but performance tests have shown marked differences in identification success. As a consequence, there remains a great need for compre- hensive studies which objectively test the method in groups with a solid taxonomic framework. This study focuses on the 180 species of butterflies in Romania, accounting for about one third of the European butterfly fauna. This country includes five eco-regions, the highest of any in the European Union, and is a good representative for temperate areas. Morphology and DNA barcodes of more than 1300 specimens were carefully studied and compared. Our results indicate that 90 per cent of the species form barcode clusters allowing their reliable identification. The remaining cases involve nine closely related species pairs, some whose taxonomic status is controversial or that hybridize regularly. Interest- ingly, DNA barcoding was found to be the most effective identification tool, outperforming external morphology, and being slightly better than male genitalia. Romania is now the first country to have a comprehensive DNA barcode reference database for butterflies. Similar barcoding efforts based on com- prehensive sampling of specific geographical regions can act as functional modules that will foster the early application of DNA barcoding while a global system is under development. Keywords: biodiversity; DNA barcoding; Lepidoptera; morphology; taxonomy 1. INTRODUCTION The proposal to develop an identification system Correct identification and monitoring of global biodiver- based on a single gene marker attracted early criticism, sity is a huge task, one that currently overwhelms the largely based on theoretical considerations such as available human resources. DNA-based identifications mtDNA introgression, incomplete lineage sorting and have the potential to resolve this problem by enabling heteroplasmy [10–14]. The method has now proved its broader participation in the process. Although mitochon- effectiveness for various groups of vertebrates (e.g. drial DNA (mtDNA) analysis has been employed in [15–17]) and invertebrates [18–25]. However, lower molecular studies on animals for more than three decades success rates have been reported in certain groups of [1], it is only recently that a short, standardized gene animals [26–33]. This variable performance may reflect region of mtDNA (50 segment of mitochondrial cyto- biological differences between taxonomic groups, the chrome c oxidase subunit I–COI ) was proposed as a sampling coverage (both in terms of geography and ‘DNA barcode’ for discriminating most animal species taxa) and the quality of the taxonomic framework. [2,3]. The application of DNA barcoding using other Therefore, some studies reporting low success have focused markers for plants has made significant progress [4,5], on groups with difficult taxonomy such as ithomine butter- as well as for fungi [6], macroalgae [7], protists [8] and flies [29]orgroupswellknownfortheirexplosive bacteria [9]. The main goals of this method are (i) to speciation such as the butterfly genus Agrodiaetus [28]. ensure fast and reliable species identification and (ii) to Such lineages are likely to represent worst case scenarios aid the discovery of undescribed species. These goals for DNA barcoding, as they actually often do for mor- complement many potential applications related to bio- phology-based taxonomy. At the opposite pole, studies diversity conservation, pest management, forensics and reporting the highest success rates for DNA barcoding healthcare. have included few closely related taxa, or have examined a limited geographical area (e.g. [2,3,34]). By careful comparison of the results from morphology and * Author for correspondence ([email protected]). DNA barcoding, our study provides the data needed to Electronic supplementary material is available at http://dx.doi.org/10. objectively assess the identification success of 1098/rspb.2010.1089 or via http://rspb.royalsocietypublishing.org. DNA barcoding. Received 21 May 2010 Accepted 23 July 2010 1 This journal is q 2010 The Royal Society Downloaded from rspb.royalsocietypublishing.org on August 12, 2010 2 V. Dinca˘ et al. DNA barcoding of Romanian butterflies The European butterfly fauna has several attributes that 4 was also used to produce the neighbour-joining tree and to make it a good test bed: it includes more than 500 species perform bootstrap analysis (100 replicates). Sequences, speci- that are a flagship for nature conservation and they have an men photographs and associated data are available at the exceptionally well-established taxonomy compared with Barcode of Life Data Systems web site (www.barcodinglife. other invertebrates. In this study, we barcode nearly all of org). Sequences are also available at GenBank (accession the butterfly species known from Romania, an area well- numbers HQ003941 to HQ005268). suited for analysis because samples can be obtained from varied habitats, altitudes and climatic influences, reflecting the fact that Romania is the only state in the European 3. RESULTS Union where five eco-regions are present (Pannonian, (a) Identification success based on DNA barcodes Continental, Alpine, Stepic and Pontic). Therefore, we Our dataset consisted of 1387 samples representing had at our disposal a dataset originating from a well- 180 species, belonging to six families (Hesperiidae, Papilio- defined region representative for the butterfly fauna of nidae, Pieridae, Lycaenidae, Riodinidae and Nymphalidae). temperate areas and consisting of an unbiased sample On average, 7.7 specimens were analysed per species. composition based on uniform collecting throughout the Only five species (2.8%) (Allancastria cerisyi, Polyommatus country’s territory. The careful comparison with morpho- amandus, Nymphalis l-album, Limenitis reducta and logical traits (using linear and/or geometric morphometry Hipparchia volgensis) were represented by one specimen when necessary) often employed in species identification and most (81.7%) had five or more records. Genetic dis- allowed an objective assessment of identification results tance to the nearest-neighbouring taxon varied from 0 to obtained through different methods and to the conclusion 11.1%, with an average of 4.7 per cent. Fifteen species that DNA barcoding is a valuable approach for the pairs (16.7%) displayed overlap between their maximum identification of temperate Rhopalocera. intraspecific variation and the minimum interspecific divergence to another taxon (figure 1a). The neighbour joining (NJ) tree profile showed that 2. MATERIAL AND METHODS sequence records for 162 of the 180 species formed dis- Methods are described in a more detailed manner (fully tinct barcode clusters allowing their unambiguous referenced) in the electronic supplementary material, annex 1. identification. The other 18 species consisted of four species pairs (4.5%) that formed paraphyletic clusters, (a) Sampling and collection data two species pairs (2.2%) that were polyphyletic and We obtained 1387 COI sequences for 180 butterfly species three species pairs (3.3%) that shared barcodes representing 99 per cent of the species with a confirmed (figure 1b). These results are unlikely