We can
thank Paul Hebert for my corny title of this week’s blog. In 2003 Paul Hebert's
research group were the first to introduce DNA Barcoding. So, what exactly is
DNA Barcoding? Well its exactly what it sounds like. DNA Barcoding is a system
used to identify species. It allows identification by using a short section of
DNA from a standardized region of the genome. The gene responsible for this amazing
discovery is a 648 base-pair region in the mitochondrial cytochrome c oxidase 1
gene ("CO1"). CO1 has been proven to be very effective, which is good
because it is cheap and can be sequenced quickly and easily. The only fault the
COI barcode has is in regard to plants. However, an alternative has been found
and scientist can use two gene regions in the chloroplast, matK and rbcL for
plant barcoding.
DNA
Barcoding can be broken down into four main components. These four components include
the specimens, the laboratory analysis, the database, and the data analysis.
DNA Barcoding of course starts with a specimen. Specimens can be collected from
a variety of places including an aquarium, a zoo, or even a museum. Once the
specimen is collected, it is brought back to a molecular biology lab and the
second part of DNA Barcoding can begin; the laboratory analysis. The first step
in laboratory analysis is tissue sampling. A tiny piece of tissue is taken from
the specimen in order to extract its DNA. Once the DNA has carefully been
extracted, PCR is used to amplify the Barcode region. During PCR, the genes are
isolated, replicated, and sequenced. Once the Barcode region is sequenced, it
is time to enter it into the Database. There are two databases that can be used.
They include, The International Nucleotide Sequence Database Collaborative and
The Barcode of Life Database. Once the data is entered, the barcoding process
is near completion and on to its final step, the data analysis. Specimens can
be identified by comparing it to the matching refences in the database.
To give a
visual example:
The
barcode sequence of an Arctic warbler (Phylloscopus
borealis), is:
CCTATACCTAATCTTCGGAGCATGAGCGGGCATGGTAGGC....
And its image looks like this:
As you can
see, the above image is very similar to that of what the cashiers scan at your
local grocery store. It is so amazing to me to learn that we can identify
unknown species by using the barcoding system!
Sources
Let me start off by saying that I enjoyed the title of your post lol. I never knew what a bar code consisted of or how they were derived. Your post was extremely informative. Great post!
ReplyDeleteI really enjoyed your post! Although we hear about most of these steps in many of our labs, I have never heard of DNA Barcoding. What I found most interesting is how the barcode sequence literally looks like a barcode! I loved your title by the way!
ReplyDeleteI personally find this topic interesting. I did my blog on this last week. It's crazy how an animal can be determined simply by DNA barcoding. I really like how you added visuals to show what they actually looked like. It helps readers understand what exactly you are talking about.
ReplyDeleteI really liked the topic you chose to write about. I never really knew too much about DNA barcoding, so it was interesting to learn about. I also really liked your visuals, it's pretty cool that it looks like an actual barcode.
ReplyDeleteReally thoughtful and entertaining. You are generating a lot of interest, and that is the purpose of a blog. Keep it up.
ReplyDelete