12 December 2005

Going to the Dogs

My heart leapt last week upon seeing the latest issue of Nature magazine. The front cover showed the iconic picture of Watson and Crick, with the latter pointing at their model of DNA's double helix. A rather striking addition was the boxer dog next to Crick, also gazing up at the DNA: inside the journal was a report on the first high-quality sequencing of the dog genome (a boxer, naturally).

This is big news. Think of the genome as a set of software modules that form a cell's operating system. Every change to a genome is a hack; like most hacks, most changes cause malfunctions, and the cell crashes (= dies/grows abnormally). Some, though, work, and produce slight variants of the original organism. Over time, these variations can build up to form an entirely new species. (In other words, one way of thinking about evolution is in terms of Nature's hacking).

Mostly, the changes produced by these hacks are small, or so slow as to be practically invisible. But not for dogs. Humans have been hacking the dog genome for longer than any other piece of code - about 100,000 years - and the result can be seen in the huge variety of dog breeds (some 400 0f them).

Getting hold of the dog genome means that scientists have access to this first Great Historical Hack, which will tell us much about how genomic variation translates to different physical traits (known as phenotypes). Even better - for us, though not for the dogs - is that all this hacking/interbreeding has produced dogs that suffer from many of the same diseases as humans. Because particular breeds are susceptible to particular diseases, we know that there must be a strong genetic element to these diseases for dogs, and so, presumably, for humans (since our genomes are so similar). The different breeds have effectively separated out the genes that produce a predisposition to a particular disease, making it far easier to track them down than in the human code.

That tracking down will take place by comparing the genomes for different breeds, and by comparing dog genomes against those of humans, mice, apes and so on. Those comparisons are only possible because all this code is in the public domain. Had the great battle over open genomics - open source genomes - been lost at the time of the Human Genome Project, progress towards locating these genes that predispose towards major diseases would have been slowed immeasurably. Now it's just a matter of a Perl script or two.

Given this open source tradition, and the importance of the dog genome, it's a pity that the Nature paper discussing it is not freely available. Alas, for all its wonderful traditions and historic papers, Nature is still the Microsoft of the science world. The battle for open access - like that for open source - has still to be won.

No comments: