DNA barcoding of the leaf-mining moth subgenus Ectoedemia s. str. (Lepidoptera: Nepticulidae) with COI and EF1-α: two are better than one in recognising cryptic species Erik J. van Nieukerken , Camiel Doorenweerd , Frank R. Stokvis , Dick S.J. Groenenberg
In direct contradiction to my previous post noting the general acceptance of COI as the universal animal barcode, a new study has just been published suggesting again that a two-gene approach to barcoding in Lepidoptera is a necessity. The authors compared the performance of COI and the nuclear gene EF1-a at distinguishing species and found a limited number of cases where species that could not be distinguished with COI could be distinguished with the nuclear gene. In another study (not cited by van Nieukerken et al.), Elias et al. drew a similar conclusion, "Despite the relatively slow rate of evolution at EF1-a, it has nonetheless resolved several cases where the mtDNA barcode failed." Both these studies used relatively restricted taxonomic samples, in contrast to the massive survey by Hebert et al., so I am not sure how far their conclusions can be generalized. In my paper, assessing the value of COI and frequently used nuclear genes for Lepidoptera phylogenetics, I found EF1-a more difficult to sequence than COI, with lower phylogenetic utility at all levels (genus, subfamily, family and superfamily), but with marginally higher phylogenetic signal. I did not compare the performance in terms of distinguishing species. It remains to be seen whether the potential payoff - enhanced resolution in a few cases - offered by EF1-a, is worth the substantial additional costs and effort required for nuclear gene sequencing.
About me
- johnjameswilson
- Liverpool, United Kingdom
- I am interested in how we can use DNA sequences to understand biodiversity – how do we recognise species, and how are species related at taxonomic, ecological and geographic levels? My passion for biodiversity research has led me from the world’s largest natural history collection - Natural History Museum, London, where I completed my MSc, to the Biodiversity Institute of Ontario - global centre for the international Barcode of Life, as a PhD student, and to the hyper-diverse tropics of Southeast Asia. The tropics will be the first regions to experience historically unprecedented climates and this will happen within the next decade. Consequently my recent research has focussed on understanding the effects of urbanisation and climate change on tropical and subtropical biodiversity - encompassing both species richness and ecological integrity across a diversity of taxonomic groups.
