DNA

DNA

~ A guest blog post by GIS student Christie Rajtar

DNA, the genetic “fingerprint” of all life, can be thought of as a barcode for any species. Genes are encoded in our DNA and have specific functions—ever heard of the bonobo? It’s a human’s closest extant relative, based on common “gene relatives”.  DNA barcoding can easily determine a species from a sample in the field. A gene called the cytochrome coxidase I is a common gene among Animalia and has uniquely evolved to each species.  Plant and Mold DNA barcoding use different genes as a reference barcode in order to determine different species of plants and molds.

DNA techniques such as sequencing can identify the DNA nucleic acids (A, C, G, and T) encoding a gene. They can be visually represented as colourful bands that are referenced to determine a species. The image below is an illustrative barcode based on the four nucleic acids of the Molossus rufus COI

bar code of life

bar code of life

The Barcode of Life Data Systems (BOLD) database provides provides both specimen informatics such as GenBank sequence data, and geographic data including GPS coordinates.

The benefits of adding geographic information to specimen data can allow us to expand our knowledge of diversity patterns and physically visit these locations for specific field studies or research work.   An interesting study by Stahlhut et al. in 2013 used DNA barcoding to identify over 900 species in Manitoba, CA. The diversity of parasitoids in their study sites implied a high level of host diversity in the same range since parasitoids cannot reproduce without hosts.

bar code of life

bar code of life

Geographically relevant areas for diversity studies can be chosen based on clues to the presence of cryptic host-parasitoid interactions offered by DNA barcoding (Stahlhut et al., 2013). University of Guelph has a BIOBus (Biodiversity Institute of Ontario) which is a mobile field research vehicle. It visits biodiversity hotspots where students and researchers can collect specimen samples for molecular analysis at the Canadian Center for DNA Barcoding and identification by taxonomists.  The International Barcode of Life project (iBOL) is creating the digital identification for life—it has an updated list of species with barcodes. The barcode library is still growing…is there a limit?

Butterflies and bar codes

Butterflies and bar codes