Oligonucleotide frequencies of barcoding loci can discriminate species across kingdoms.

• Main Authors: Antariksh Tyagi, Sumit K Bag, Virendra Shukla, Sribash Roy, Rakesh Tuli
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2010-01-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC2924895?pdf=render

BACKGROUND: DNA barcoding refers to the use of short DNA sequences for rapid identification of species. Genetic distance or character attributes of a particular barcode locus discriminate the species. We report an efficient approach to analyze short sequence data for discrimination between species. METHODOLOGY AND PRINCIPAL FINDINGS: A new approach, Oligonucleotide Frequency Range (OFR) of barcode loci for species discrimination is proposed. OFR of the loci that discriminates between species was characteristic of a species, i.e., the maxima and minima within a species did not overlap with that of other species. We compared the species resolution ability of different barcode loci using p-distance, Euclidean distance of oligonucleotide frequencies, nucleotide-character based approach and OFR method. The species resolution by OFR was either higher or comparable to the other methods. A short fragment of 126 bp of internal transcribed spacer region in ribosomal RNA gene was sufficient to discriminate a majority of the species using OFR. CONCLUSIONS/SIGNIFICANCE: Oligonucleotide frequency range of a barcode locus can discriminate between species. Ability to discriminate species using very short DNA fragments may have wider applications in forensic and conservation studies.