A DNA microarray for identification of selected Korean birds based on mitochondrial cytochrome c oxidase I gene sequences.

DNA barcoding with the gene encoding cytochrome c oxidase I (COI) in the mitochondrial genome has been proposed as a standard marker to identify and discover animal species. Some migratory wild birds are suspected of transmitting avian influenza and pose a threat to aircraft safety because of bird strikes. We have previously reported the COI gene sequences of 92 Korean bird species. In the present study, we developed a DNA microarray to identify 17 selected bird species on the basis of nucleotide diversity. We designed and synthesized 19 specific oligonucleotide probes; these probes were arrayed on a silylated glass slide. The length of the probes was 19-24 bps. The COI sequences amplified from the tissues of the selected birds were labeled with a fluorescent probe for microarray hybridization, and unique hybridization patterns were detected for each selected species. These patterns may be considered diagnostic patterns for species identification. This microarray system will provide a sensitive and a high-throughput method for identification of Korean birds.

DNA barcoding Korean birds.

DNA barcoding, an inventory of DNA sequences from a standardized genomic region, provides a bio-barcode for identifying and discovering species. Several recent studies suggest that the sequence diversity in a 648 bp region of the mitochondrial gene for cytochrome c oxi- dase I (COI) might serve as a DNA barcode for identify- ing animal species such as North American birds, in- sects and fishes. The present study tested the effective- ness of a COI barcode in discriminating Korean bird species. We determined the 5' terminus of the COI bar- code for 92 species of Korean birds and found that spe- cies identification was unambiguous; the genetic differ- ences between closely related species were, on average, 25 times higher than the differences within species. We identified only one misidentified species out of 239 specimens in a genetic resource bank, so confirming the accuracy of species identification in the banking system. We also identified two potential composite species, calling for further investigation using more samples. The finding of large COI sequence differences between species confirms the effectiveness of COI barcodes for identifying Korean bird species. To bring greater reliability to the identification of species, increased in- tra- and interspecies sampling, as well as supplementa- tion of the mitochondrial barcodes with nuclear ones, is needed.