DNA barcoding

I tried to understand what DNA barcoding is, as everyone is talking about it. And I tried reading a couple of papers about it - I am a biologist, so I should have understood them, but nope, I was still in the dark.

So, what does one do? Waits for a science blogger to explain it. And so it happens, Karen explained it yesterday. I read it. Slowly and carefully. Only once. And I grokked it all!

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Ah-ha!
I too had encountered the barcode terminology without a clear explaination- that's a great post. Glad you helped me find it.

I use barcoding techniques to solve a pesky problem regarding insect-parasite associations. I've had to identify unique host-parasite combinations within a community, but don't have the taxonomic expertise to identify the host species, at least not below the family level. Farming the critters out to taxonomists would take years, and would also require preservation methods that would ruin the specimens for molecular work. Also, putting a definitive species name on the host is not absolutely necessary for me.

So, I use the COI barcoding sequence, not to put a definitive ID on my insect specimens, but as evidence of whether two similar insects are likely to belong to the same species. Won't say much more until the paper comes out, but let's say that COI identification has been very useful, and in my work its results are supported by at least one independent line of evidence.

As for barcoding databases, they're like GenBank in the early days. They will become more and more useful as more information is added to them, and they will complement rather than replace traditional taxonomy. Before you can use a COI sequence to show that the ants you collected are Camponotus novaboracensis, a reference sequence has to be obtained from one or more specimens that were identified by someone who has expertise in morphological determination of ant species.

By Julie Stahlhut (not verified) on 19 Feb 2008 #permalink