Wednesday, June 9, 2010

It's not all fun and games; or, what I'm actually doing here

Fig. 1: the morning commute. 

You might think, based on the few posts so far this season, that "field" work for this marine-biologist-cum-entomologist consists entirely of traipsing happily through tick-infested woods, merrily climbing trees and peeing in all sorts of containers. And if my work day ended in the mid-afternoon, you'd be right. (I would dearly like for this to be the case, but alas!)

Oh no -- there is so much more fun to be had. Behold: the lab!

Fig. 2: pit of eternal despair lab station

The real reason I've flown halfway around the world, instead of just asking friendly scientists like Scott for some spare ants, is that I'm hoping to look inside the ants at the communities of microbes inhabiting their gastrointestinal tracts. Recent research by the fantastic Jake Russell, Corrie Moreau, and others suggests that ants with a mostly-vegetarian lifestyle (like yours truly!) have evolved unique partnerships with certain microbes. These microbes (some of which, incidentally, seem to be closely related to the bacteria that fix nitrogen in legumes) may be important in providing the ants certain nutrients -- such as nitrogen in the form of essential amino acids -- that are limited or absent in their plant-based diets. We humans also have important communities of microbes in our guts, that provide us all sorts of services that we're only just begging to understand and appreciate. I'm interested in how relationships in these microbial communities have evolved in concert with their host animals: have certain microbes evolved in parallel with their hosts over millions of years, or is it a big free-for-all with frequent partner swapping? Do the communities in ants look similar to those in humans and other vertebrates, and do they behave the same way? Are there some over-arching rules we can piece together governing these kinds of complex relationships?

Ants, for a bajillion different reasons that I won't go into right now, make really cool systems in which to study these questions. And we happen to have, at my research institution, the world's largest collection of ant specimens (really!). The thing is, most of these specimens aren't really any good for the questions I'm asking. When people like my office-mate E.O. Wilson (ed. note: I still have a hard time believing this) collected ants over the years, they spent a lot of time making sure the specimens were useful for ant taxonomy, and not a lot of time thinking about the microbes within.

While there's still a lot you can do with 'normal' ethanol-preserved specimens (Profs. Russell and Moreau's recent PNAS paper was done using mostly these kinds of samples), after a certain point you'd like to start using samples that were collected with microbes in mind. That's when things start to get crazy.

If you've ever hung out with a microbial ecologist, you'll get what I mean. Microbiologists are cut from something of a different cloth than your typical entomologist. Where insects might seem to be everywhere, microbes really are everywhere. As in, literally, everywhere. One must got to extreme, perverse lengths to try and manufacture places where microbes aren't. So if your questions is "which microbes are present in this sample?" and you'd like not to answer instead "which microbes are present in this sample, and on my hands, and in my hair, and on this bench, and just kind of floating around in the air, and also apparently thumbing their noses at Louise Pasteur and spontaneously generating from the aether" then you have to start being a new kind of anal.

Fig. 3: a new kind of anal. As in, an ant's dissected GI tract. a: ileum (where the magic microbes live). b: rectum. c: other bits.

So that's why I'm here, in person, with $400 worth of tweezers. In addition to catching a whole bunch of different ants, I'm also preparing them in all sorts of extra special ways in the hopes of getting good, clean information on the microbes living within. That means coming back from the field, washing up, sitting down in front of a microscope with my extreme tweezers, and dissecting the guts out of hundreds of ants (pictured above).

Hey, it beats flipping burgers...

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