DNA barcoding has been proposed as a mechanism for speeding up the process of cataloguing life on earth. It is based on the premise of using a standard short region of DNA as a universal tool for identifying organisms. The aim is to establish a large-scale reference sequence database against which unknown samples can be queried for identification. Where sequences are found that are divergent from others in the database, the corresponding specimens are flagged up as potential new species warranting further investigation.
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Current research effort on DNA barcoding includes:
Selecting an appropriate region of DNA for barcoding land plants
There is currently no consensus on the most appropriate DNA region(s) for plant barcoding. Several different chloroplast genes and spacers have been proposed by different research groups (summarised by Pennisi (2007), Science, 318: 190-191, and Ledford (2008), Nature, 451: 616). Efforts are being made to compile data matrices from the different research groups and to reach a community consensus on the most appropriate plant barcoding regions.
For further information contact Pete Hollingsworth, chair of the ‘Plant Working Group' Consortium for the Barcode of Life, or visit the Plant Working Group pages
Barcoding the British liverwort flora
Liverwort species can be difficult to identify using morphological characters, cryptic species frequently occur, and there is a shortage of taxonomic experts. DNA barcoding can thus be used as a tool for species identification and taxonomic clarification. In collaboration with RBGE's bryologist David Long, we are using the British liverwort flora (ca 300 species) as a model to evaluate the performance of DNA barcoding in liverworts.
General evaluation of the performance of DNA barcoding techniques
A single short stretch of organelle DNA will not provide species level resolution in all plant groups. Recent diversification and hybridisation will result in the sharing of chloroplast haplotypes among species. We are interested in establishing how often cpDNA regions provide species level resolution in different plant groups, and conversely in which groups additional assays are required.
For more information on DNA barcoding at the Royal Botanic Garden Edinburgh, contact Pete Hollingsworth
Recent DNA barcoding publications:
- Hollingsworth PM. (2008) DNA barcoding plants in biodiversity hot spots: progress and outstanding questions. Heredity
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Chase MW, Cowan RS, Hollingsworth PM, van den Berg C, Madrinan S, Petersen G, Seberg O, Jorgsensen T, Cameron KM, Carine M, Pedersen N, Hedderson TAJ, Conrad F, Salazar GA, Richardson JE, Hollingsworth ML, Barraclough TG, Kelly L and Wilkinson M. (2007) A proposal for a standard protocol to barcode all land plants. Taxon 56: 295-299.
- Hollingsworth PM. (2007) DNA barcoding: potential users. Genomics Society and Policy 3: 44-47.
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Long DG, Paton JA, Squirrell J, Woodhead M, Hollingsworth PM. (2006) Morphological, ecological and genetic evidence for two species in one: Anastrophyllum joergensenii Schiffn. and A. alpinum Steph. (Hepaticae; Lophoziaceae). Journal of Bryology 28: 108-117.
RBGE staff involved in DNA barcoding
Pete Hollingsworth
Michelle Hollingsworth (Science and Technical Services Group)
James Richardson (Tropical Biology Group)
Laura Forrest (Science and Technical Services Group)
Jane Squirrell
Kath Evans (Diatom barcoding)
David Mann (Cryptogamic group)
David Long (Cryptogamic group)