April 25th (4/25) is national DNA day. Digital World Biology ™ celebrates by sharing some of our favorite DNA structures. We created these photos with Molecule World ™ Molecule World is a tools for exploring molecular and chemical structures on an iPhone or iPad.
A key concept in science is molecular scale. DNA is a fascinating molecule in this regard.
While we cannot "see" DNA molecules without the aid of advanced technology, a full length DNA molecule can be very long. In human cells, other than sperm and eggs, six billion base pairs of DNA are packaged into 22 pairs of chromosomes, plus two sex chromosomes. Each base pair is 34 angstroms in length (.34 nanometers, or ~0.3 billionths of a meter), so six billion base pairs (all chromosomes laid out head to toe) form a chain that's two-meters long. If we could hang this DNA chain from a hook, it ... Read more
In our series on why $1000 genomes cost $2000, I raised the issue that the $1000 genome is a value based on simplistic calculations that do not account for the costs of confirming the results. Next, I discussed how errors are a natural result of the many processing steps required to sequence DNA and why results need to be verified. In this and follow-on posts, I will discuss the four ways (oversampling, technical replicates, biological replicates, and cross-platform replicates) that results can be verified as recommended by Robaskyet. al. .
Previously , I introduced the idea that the $1000 genome has not been achieved because it is defined in simplistic terms that ignore many aspects of data completeness and verification. In that analysis, I cited a recent perspective by Robasky, Lewis, and Church  to present concepts related to the need to verify results and the general ways in which this is done. In this and the next few posts I will dig deeper into the elements of sequence data uncertainty and discuss how results are verified.
In simple Mendelian genetics, a single change in one gene can produce a large change in mortality. The National Human Genome Research Institute (NHGRI) will be funding genomics studies on Mendelian traits using a similar strategy.
NHGRI will fund a small number of centers, dominant centers you might say, and look for large changes. The sequencing centers that will benefit are the Broad Institute, Washington University, and Baylor College of Medicine. For the next four years, the big three will be dividing $86 million a year according to a press ... Read more
An NSF post on Twitter this morning described an interesting study from the University of Pennsylanvia and Cornell University, that found that some people who call themselves "African Americans" may only be 1% West African, according to their DNA.
The University of Pennsylvania press release contains other interesting findings as well. 365 individuals were studied and 300,000 genetic markers were examined.
Some of the findings were:
If you're African American, the genes most likely to have an African origin are those on your
For the past few months, the shake-up that began with Next Generation DNA Sequencing has been forcing me to adjust to a whole new view of things going on inside of a cell. We've been learning things these past two years that are completely changing our understanding of the genome and how it works and it's clear we're never going back to the simple view we had before.
What's changed? The two most striking changes, to me at least, are the new views of the way the genome is put together and what the cell does with the information.
They just don't assemble chromosomes like ... Read more
Cofactor Genomics is offering to sequence a genome for a few classes for free using Next Generation DNA Sequencing technology (either Illumina GA or via AB SOLiD).
Quoting from their site:
Cofactor will ask course organizers for a 1 page description of how their ~700Mb sequencing project could be used as an effective teaching aid in their class. We will review and choose the best entries during the month of May. Those entries will be awarded a free sequencing project ... Read more
Maybe you did it for the extra cash. Maybe you wanted to be part of the sperm cube public art project. Whatever the reason, it's possible, just possible, your sperm took on a life of it's own, once you left it.
And now that a genome is no longer an entirely personal bit of information, you may be in for a surprise meeting someday, with the end result.
Male adoptees are getting their DNA tested and getting information about their possible surnames.
According to ... Read more