Sunday, August 16, 2009

The last two posts have clearly dealt with the theme “rock ‘n roll”, so we are due for a post about parasites. A very exciting experiment of ours came to an abrupt, unplanned end last week. Some background…As a model system we are working with a tapeworm that uses sticklebacks (small fish) as intermediate host. This worm invades the body cavity of sticklebacks and then grows voraciously. The mature worm is so large that it distends the abdomen of the fish and can account for up to 50% of the fish’s weight. A large size benefits the worm, because larger individuals produce more eggs in the next host, fish-eating birds. However, to achieve such prolific growth, worms seem to suppress the fish’s immune system. In a wormy world, this might be risky. By suppressing its host’s defenses, the worm potentially opens the door for other parasites, which might be competitors or on their way to different host’s (e.g. predatory fish). To test this scenario, we infected fish with two tapeworm strains that differed in their growth rates, and then placed the fish in cages in the lake. We intended to leave the fish in the lake until September, so that they would be exposed to a whole summer’s worth of parasites. However, two weeks ago, we observed a spike in fish mortality. So, before our whole batch of experimental fish died off, we decided to undertake an emergency dissection. Unfortunately, the majority of the institute’s technical staff has chosen mid-August for their holidays, so we had to process all these fish with less help than accustomed or expected. Here’s the rough procedure: kill the fish, check the skin, fins, and mouth for ectoparasites, weigh and measure the fish, take a fin clip for DNA identification of the fish, open the body cavity and check for our nasty tapeworm, weigh any worm that is present, take the spleen and head kidneys for possible gene expression studies, dissect the eyes for flukes, squeeze the liver, gonads and intestine for endoparasites, and, finally, freeze the rest of the carcass so the muscles and gills can be checked later. Each little fish requires a lot of work; just checking the eyes can take up to an hour. We had to put in some night-shifts, but we managed to finish the last fish late Friday night. After this dissection-marathon, I’m looking forward to resting my back and not opening another fish eye for some time. I am convinced that the whole effort will yield some very interesting data. Which brings me to a metaphor: big experiments are like binge drinking. We tend to remember the positive parts of it (good data or a nice buzz), but not the negative (an aching back or a wicked hangover).

On another, less-interesting work theme, much of my time has been consumed by report-writing. Every two years, the institute is evaluated by a board of international experts. Essentially, it is the board’s job to assess whether all that government money produced some high-quality research, and it is our job to convince them that we have done lots of spectacular research. In a long, boring report, we detail our work, results, and future plans. I imagine that most of the board members barely read the report, instead browsing through the publication list, checking in which journals we published and how often. Nonetheless, the time devoted to this is excessive. We had two epically long (3-hour) and boring meetings (shoot me) to discuss the content and outline of the bloody thing. And guess who was elected to proofread the 40 page report? Yeah, damn my good English.

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