Today’s tip is on a TARGeT. TARGeT is, as the the paper’s title in the this year’s NAR’s issue states, “a web-based pipeline for retrieving and characterizing gene and transposable element families from genomic sequences.” There are several things you can do at TARGeT. Using BLAST, PHI BLAST, MUSCLE and TreeBest ,the main function of TARGeT is to quickly obtain gene and transposon families from a query sequence. The tip today is a quick intro to the tool and a search on an R1 non-LTR transposon.
Barcoding Plant DNA (I hope the embed of the audio file works, first time I’m trying that…)
It is a discussion with Dr. Damon Little, a curator of bioinformatics from the New York Botanical Garden. The focus of the discussion is the recent publication of the CBOL Plant Working Group which has settled on the regions that will be used for barcoding plants.
If you aren’t familiar with barcoding efforts yet, you can check out Jennifer’s prior post with some background and great links. Essentially a small snippet of DNA sequence is used to (hopefully) uniquely identify a given species. This can be stored in a database–Dr. Little of the NY Botanical Garden refers to GenBank at NCBI, but there are other sites as well. I was just reading about the web interface for barcoding called iBarcode.org for analyzing and managing this sort of data.
The Consortium for the Barcode Of Life Plant Working Group summary press release of this work can be found here. The paper that describes the work is Open Access in PNAS here. The paper describes the genes that had been candidates for the barcode, and the ones that were selected (rbcL + matK). They described primer selection and sequencing results for the series they examined. They evaluate which ones meet the barcoding standard criteria and provide the selections. They use MUSCLE to examine the sequence alignments.
This is an excellent effort on many fronts. Just assessing and cataloging biodiversity is useful itself, but this can also help to identify plants that are claimed to be used in food or medicine products to see if that is what’s really in there. It can help combat poaching of protected species–for example, it can identify wood harvested that shouldn’t have been taken for lumber.
Glad to see this work moving forward and getting out in front of the public!
Podcast direct page: http://www.wnyc.org/shows/lopate/episodes/2009/07/29/segments/137623
Barcode blog: http://phe.rockefeller.edu/barcode/blog/
Scientific American article on the topic: http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=botanists-agree-on-dna-barcode-for-2009-07-29
Consortium for the Barcode of Life (CBOL): http://www.barcoding.si.edu/
CBOL Plant Working Group (2009). A DNA barcode for land plants PNAS, 106 (31), 12794-12797 : 10.1073/pnas.0905845106
Singer, G., & Hajibabaei, M. (2009). iBarcode.org: web-based molecular biodiversity analysis BMC Bioinformatics, 10 (Suppl 6) DOI: 10.1186/1471-2105-10-S6-S14
Edgar, R. (2004). MUSCLE: multiple sequence alignment with high accuracy and high throughput Nucleic Acids Research, 32 (5), 1792-1797 DOI: 10.1093/nar/gkh340
So, you’ve got your sequences aligned using Clustal, Muscle or T-Coffee (or other program), you’ve created a tree data file using PAUP, Phylip or one of the other many algorithms out there, now you want to draw and visualize those relationships. A good place to go to find a list of tools to do that is at the huge list of phylogeny tools at Department of Genome Sciences at the University of Washington (there is a lot more than just tree drawing of course!). Many of these tools are downloaded and feature rich, one might suit your needs, so check them out. One this tip points out is Phylodendron, which you can download, but also has a web interface. This will allow you to quickly draw a tree for viewing.