sequence analysis
sporte | September 25, 2008Do mosquitoes get the mumps? Part V. A general method for finding interesting things in GenBank
This is the last in a five part series on an unexpected discovery of a paramyxovirus in mosquitoes and a general method for finding other interesting things.
In this last part, I discuss a general method for finding novel things in GenBank and how this kind of project could be a good sort of discovery, inquiry-based project for biology, microbiology, or bioinformatics students.
I. The back story from the genome record
II. What do the mumps proteins do? And how do we find out?
III.…
sporte | September 24, 2008Part IV. Assembling the details and making the case for a novel paramyxovirus
This is the fourth in a five part series on an unexpected discovery of a paramyxovirus in a mosquito. In this part, we take a look at all the evidence we can find and try to figure out how a gene from a virus came to be part of the Aedes aegypti genome.
image from the Public Health Library
I. The back story from the genome record
II. What do the mumps proteins do? And how do we find out?
III. Serendipity strikes when we Blink.
IV. Assembling the details of the case for a novel mosquito paramyxovirus
V. A…
sporte | September 23, 2008Every fall, we had to confront it. People would let their dogs run around on the field in the morning and by the time soccer practice started, the field would be full of deadly doo.
There's nothing that hurts soccer practice more than a soccer ball or shoes that went through a pile of dog poo.
That's why I'm so exciting to see this new application for DNA testing. That's right. Kids will be able to play soccer without worry and dog owners will be held responsible for cleaning up after their pets.
The forward thinking city that's going to implement this plan is Petah Tikva, in Isreal.…
sporte | September 23, 2008Part III. Serendipity strikes when we Blink
In which we find an unexpected result when we Blink while looking at the mumps polymerase.
This is the third in a five part series on an unexpected discovery of a paramyxovirus in mosquitoes. And yes, this is where the discovery happens.
I. The back story from the genome record
II. What do the mumps proteins do? And how do we find out?
III. Serendipity strikes when we Blink.
IV. Assembling the details of the case for a mosquito paramyxovirus
V. A general method for finding interesting things in GenBank
To paraphrase Louis Pasteur,…
sporte | August 25, 2008A few days ago, I wrote about a cool project that some high school students did where they used DNA sequencing to identify seafood.
One question that came up from one of my commenters was how a school would start a project like this. I'm totally biased, but I think DNA sequencing (well, actually the data analysis) is one of the most interesting things that a class can do as part of a research project. These days, getting started with this kind of project, wouldn't be so hard.
Here's are some ways that I would get started:
Find an existing project where my students could collaborate and…
sporte | August 21, 2008One of the things that drives me crazy on occasion is nomenclature. Well, maybe not just nomenclature, it's really the continual changes in the nomenclature, and the time it takes for those changes to ripple through various databases and get reconciled with other kinds of information. And the realization that sometimes this reconciliation may never happen.
One of the projects that I've been working on during the past couple of years has involved developing educational materials that use bioinformatics tools to look at the isozymes that metabolize alcohol. As part of this project, I've been…
sporte | August 12, 2008Ancestry tests aren't just for humans anymore. We went to Petco this weekend to buy dog food and found brochures for doggy DNA testing. Now, those of you with dogs of uncertain parentage need puzzle no longer. According to Petco, their SNP test (what is a SNP?) can identify over 100 different breeds and they'll tell you which breeds are represented in your dog and whether your dog's breeding is mixed (or pure).
The brochure from Petco also claims that knowing something about your puppy's parentage could be helpful in understanding their behavior and potential health risks. That's probably…
sporte | August 6, 2008This the third part of case study where we see what happens when high school students clone and sequence genomic plant DNA. In this last part, we use the results from an automated comparison program to determine if the students cloned any genes at all and, if so, which genes were cloned. (You can also read part I and part II.)
Did they clone or not clone? That is the question.
But first, we have to answer a different question about which parts of their reads are usable and which parts are not. (A read is the sequence of bases obtained from a chromatogram file.)
How does our data get…
sporte | August 5, 2008This the second part of three part case study where we see what happens when high school students clone and sequence genomic plant DNA. In this part, we do a bit of forensics to see how well their sequencing worked and to see if we can anything that could help them improve their results the next time they sequence.
How well did the sequencing work?
Anyone who sequences DNA needs to be aware of two kinds of problems that afflict their results. We can divide these into two categories: technical and biological.
Technical problems are identified using quality values and the number of bases…
sporte | August 4, 2008What happens when high school students clone and sequence genomic DNA?
Background
DNA sequencing is a wonderful tool for discovery and a great technique for getting students involved in molecular science. This fall, Bio-Rad will officially begin selling their DNA cloning and sequencing kit. Now, students across the country will have the tools in hand to begin their own projects cloning and sequencing plant genes.
Of course, without bioinformatics there's no way to know what's been cloned or sequenced.
This is where we come in. As part of an agreement with Bio-Rad, we adapted a version of…
sporte | June 17, 2008In its simplest sense, we imagine that learning occurs through a series of positive and negative rewards. Some actions lead to pleasure, others to pain, and it seems reasonable to expect that people will repeat the actions with pleasurable results and avoid those that ended in pain. Yet, we all know people who aren't deterred by the idea of punishment. We all know people who never seem to learn.
Could there be a physical reason, hidden in their genes?
In December 2007, Science published a study by Klein et. al. (1) where they asked if a specific genotype at a location called "DRD2-TAQ-IA"…
sporte | June 4, 2008Have you ever wondered what kinds of viruses can be found in human waste?
Mya Breitbart and team have been sequencing nucleic acids from fecal samples in order to find out. You might expect that we'd find viruses that infect humans or viruses that infect the bacteria in our gut.
I wouldn't have expected to learn the result that they found.
A large number, 60% of the viral DNA sequences were from unknown viruses. That's not a surprise. The surprise came when they looked at the RNA viruses.
Instead, the viral sequences most often came from a plant pathogen called the pepper mild mottle…
sporte | June 4, 2008I'm in Berkeley right now at the annual Bio-Link Summer Fellows forum. We're getting to hear talks from people in the biotech industry, listen to enthusiastic instructors describe their biotech programs and ideas, and try out new educational materials.
Yesterday, two speakers (Damon Tighe and Jason Baumohl) from the Joint Genome Institute in Walnut Creek, CA, gave a fun talk about DNA sequencing and sequence assembly.
They also showed some very nice Flash animations, made by Damon Tighe, at the JGI, that illustrate how DNA sequencing is done. There's no sound, but the animations are…
sporte | May 29, 2008I got my copy of "A short guide to the human genome" by Stewart Scherer today from Cold Spring Harbor Laboratory Press (2008, ISBN 978-087969791-4). Usually, I would wait until after I've read a book to write a review, but this book doesn't require that kind of study. As soon I skimmed through it and read some of the questions and answers, I knew this would be the kind of quick reference that I would like to have sitting above my desk.
Scherer has compiled a wonderful text that not only answers many of the kinds of questions that I can think to ask about the human genome, but the kinds of…
sporte | May 8, 2008Dave Robinson and Joann Lau from Bellarmine College in Kentucky are going to be describing their student project in a free webinar next Friday, May 16th. Their students clone GAPDH (Glyceraldehyde 3-Phosphate Dehydrogenase) genes from new plants, assemble the DNA sequences, and submit them to the NCBI. Here's an example.
Plus, since GAPDH is a highly conserved, it's a great model for looking at evolution.
You can get more information and register here.
The cool thing about plants is that there's lots of material to work with.
sporte | April 27, 2008A potential link between lung cancer and human papilloma virus may make parents even more glad about vaccinating their children with Gardasil®. Not only are the children protected against viruses that commonly cause cervical cancer, they may be protected against some forms of lung cancer as well.
The April 25th version of Nature News reports (1) that two viruses, HPV (Human papilloma virus) and measles virus, have been found in lung tumors.
From Nature News:
Samuel Ariad of the Soroka Medical Center in Beer Sheva, Israel, and his colleagues began by analyzing tumours taken from 65 lung…
sporte | April 24, 2008Bill Gates, Eric Lander, Maynard Olson, Leena Peltonen, and George Church fielded questions last night at a fascinating panel discussion on personal genomics at the University of Washington.
We were fortunate to be in the audience. I'll share some of the questions and answers, in some cases shortened and paraphrased.
The room in Kane Hall at the UW was already warm when we arrived last night (yes, I do go to evening seminars). A student handed us cards and cute little pencils for writing our questions and we sat down. We fought the impulse to write "What's the air speed velocity of a coconut-…
sporte | April 22, 2008One of my favorite web 2.0 technologies is the webinar. When you work at a company and not a University, with constant seminars, it gets a bit harder to hop on a bus and travel across town to learn about new things. Webinars are a good way to fill that gap. I grab my coffee cup, put on my headphones, and I get to listen to someone tell me about their work for an hour and show slides over the web. It's nice.
Our company is even going to be involved in two webinars in the next two months. One of us is giving an Illumina webinar tomorrow on managing Next Generation Sequencing data. A…
sporte | April 17, 2008In the class that I'm teaching, we found that several PCR products, amplified from the 16S ribosomal RNA genes from bacterial isolates, contain a mixed base in one or more positions.
We picked samples where the mixed bases were located in high quality regions of the sequence (Q >40), and determined that the mixed bases mostly likely come from different ribosomal RNA genes. Many species of bacteria have multiple copies of 16S ribosomal RNA genes and the copies can differ from each other within a single genome and between genomes.
Now, in one of our last projects we are determining where…
sporte | April 11, 2008I know some of you enjoy looking at data and seeing if you can figure out what's going on.
For this Friday's puzzler, I'm going to send you to FinchTalk, our company blog, to take a look at lots of data from a resequencing experiment that was done to look for SNPs and count alleles. The graph is at the end of the post.
The graph shows data from 4608 reads (sequenced from both strands, forward and reverse). And there are some interesting patterns. Can you figure them out?