Tuesday, August 18, 2009

In defense of big genetics   posted by p-ter @ 8/18/2009 08:19:00 PM

Greg Mayer, filling in for Jerry Coyne, has a post up on a somewhat odd objection to the appointment of Francis Collins as director of NIH: that he's a geneticist. The argument seems to be that diseases are complicated and not entirely genetic, and that Collins isn't hip to non-genetic subtleties. To be frank, this is silly--while it's sometimes a revelation to non-biologists that the "gene for X" way of framing things is inaccurate, Collins is not incompetent. If I had to guess what direction he's planning on taking the NIH, I'd look to what he's actually written.

In the comments to the post, there's the additional worry that Collins represents "big science", which I suppose is considered to be a bad thing (apparently Collins thinks it would be nice to catalogue all the transcripts in a cell, which for whatever reason really pissed off this dude). It's not a bad thing at all; in many cases, big, relatively hypothesis-free science is actually really nice for rationally choosing which "little science" projects to pursue.

Let's take a couple recent examples from genome-wide association studies (these studies over the past few years have exponentially increased our understanding of complex disease; whether that exponential increase is enough for you depends on your prior expectations). First, a little over two years ago, an association was found between a genetic variant in the FTO gene and obsesity in humans. At the time, the gene had unknown function. Now, there's a mouse model and focused biochemical analysis being done on this gene, and we're light years closer to understanding what it does and how nearby variation influence obesity. Would all of this been done without the "hypothesis-free" GWAS? Not anytime soon.

Second, consider the genome-wide association studies in several cancers that all pointed to the same, gene-free region on chromosome 8. In the last few weeks, three separate groups have published their "small-scale" molecular biology work establishing that the associated region appears to be an enhancer important for either proper temporal or spatial gene expression. How does it work? It's not clear, but that's the point--this is an interesting question. Much of "small-scale" molecular biology is done in a few model systems, or on a few "popular" genes. There's a very good reason for this--these systems or genes are already known to be interesting either scientifically or medically. One efficient way to identify novel, potentially interesting systems is through large-scale work.

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