 | |
Barcodes can tell us what species an animal is
|
Why do scientists need an easy sure fire way to identify animal species? Sometimes very similar looking species can be very different; poisonous species sometimes look like harmless ones, rare and endangered species sometimes look like common ones, species that may contain valuable compounds for medicine or industry may look like ones that don't. So, knowing the exact species of an animal is important for environmentalists, consumers, and researchers.
Taxonomists (scientists who specialize in naming and describing species) often train for years to learn to identify difficult specimens. Unfortunately, each year fewer young scientists are being trained as taxonomists. And sometimes, if a specimen is very young or very damaged, even an expert taxonomist can't identify it to species just by looking at it. For example, it is sometimes important to know whether the fillet in your grocer's freezer is really from a sustainably farmed Arctic Char, as the label states, rather than from some cheaper overfished or illegally caught species. Problems like these point to the need for a new way to identify species, one that does not require experts and intact, well-preserved specimens. One solution: use DNA sequences as a "barcodes" for identifying species.
DNA sequences differ among species. Once differences are identified, they can be used as diagnostic traits to identify species, just like the color of an animal may be a diagnostic. Scientists at the Barcode of Life project (www.barcodeoflife.org) have chosen a segment of DNA called the mitochondrial COI (pronounced "see-oh-one") gene as the specific barcode for all organisms.
Researchers all over the world are sending tissues from expert-identified organisms to the Canadian Center for DNA Barcoding (CCDB; www.dnabarcoding.ca), and other Barcoding centers around the world, to serve as DNA references. CCDB reads the sequences of COI genes from all of these tissues and is creating a database of sequences (which can be found at www.boldsystems.org). Now, if a researcher collects an animal she cannot identify, she can sequence the COI gene and compare it to the sequences in the database. If the DNA sequence from the unknown animal matches the sequence of an identified animal, the mystery is solved, just like in the example below!
 | By comparing COI sequences from an unknown animal to those of known animals, the identify of the unknown animal can be determined.
NOTE: These are examples, not real COI sequences.
|
Our colleagues at the CCDB are leading a project called the Marine Barcode of Life Initative or MarBOL (www.marinebarcoding.org). MarBOL's goal is to find DNA barcodes for all marine species. OGL is aiding this global iniative by providing DNA from our collection of expert-identified marine animals. OGL has already submitted almost 1,700 samples to this project! We are proud to be taking part in this important global initiative and thank all of our collaborators and depositors for contributing to this exciting project! |
