Did you know small fragments of DNA are circulating in your blood stream?
These short pieces of DNA are left behind after cells self-destruct. This self-destruction, or apoptosis, is a normal process. In the case of fetal development, certain cells in our hands die, leaving behind individual fingers. Immune system cells leave traces of DNA behind after they’ve tackled invading microbes. DNA can also appear in the blood when people have cancer.
I had the good fortune, last Monday, to hear Matthew Snyder describe this cell-free DNA in a fascinating talk and learn why DNA in the blood can be a ... Read more
A few weeks back, we published a review about the development and role of the human reference genome. A key point of the reference genome is that it is not a single sequence. Instead it is an assembly of consensus sequences that are designed to deal with variation in the human population and uncertainty in the data. The reference is a map and like a geographical maps evolves though increased understanding over time.
Getting an accurate genome sequence requires that you collect the data at least twice argue Robasky, Lewis, and Church in their recent opinion piece in Nat. Rev. Genetics [1].
The DNA sequencing world kicked off 2014 with an audacious start. Andrew Pollack ran an article in the New York Times implying that 100,000 genomes will be the new norm in human genome sequencing projects [2]. The article focused on a collaboration between Regeneron and Geisinger Health in which they plan to sequence the exomes (the ~2% of the genome that encodes proteins and some non-coding RNA) of 100,000 individuals ... Read more
One of the interesting things I learned today was that many people are calling for the genome sequences of the chimps and Macaques to be finished.
This is especially amusing because the human genome isn't quite done. We're primates, too! Why not finish our genome?
[I blame these new-found revelations on Twitter. Despite my youngest daughter's warning that only old people use Twitter, I've joined my SciBlings and taken the plunge. (you can even follow me! @digitalbio).
Now, I get to indulge my geeky tendencies while waiting ... Read more
We'll have a blast, I promise! But there's one little thing we need to discuss first...
I want to explain why I'm going to use nucleotide sequences for the blast search. (I used protein the other day). It's not just because someone told me too, there is a solid rational reason for this.
The reason is the redundancy in the genetic code.
Okay, that probably didn't make any sense to those of you who didn't already know the answer. Here it is. ... Read more
Let's play anomaly!
Most of this week, I've written about the fun time I had playing around with NCBI's Blink database and finding evidence that at least one mosquito, Aedes aegypti, seems to have been infected at some point with a plant paramyxovirus and that the paramyxovirus left one of its genes behind, stuck in the mosquito genome.
During this process, I realized that the method I used works with other viruses, too. I tried it with a few random viruses and sure enough, I found some interesting things.
You've got a week to give it a try. Let's see ... Read more
Lots of bloggers in the DNA network have been busy these past few days writing about Google's co-founder Sergey Brin, his blog, his wife's company (23andme), and his mutation in the LRRK2 gene.
I was a little surprised to see that while other bloggers (here, here, ... Read more
Do 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 ... Read more
Part 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.
Part 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. ... Read more
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