Keratocytes — Wishing Harvard Taught Fishing
My sister works with fish. She spends a large part of her time sloshing around in a fish tank trying to catch the lab pets. I figure that her Harvard degree makes her one of the world’s better educated bare-hand fishers.
Some of these pets are rather rambunctious. One, for instance, decided that it’d be nice to jump out of her tank and say hello to the post-doc who sits next to her. While this was a nice thought, it only resulted in scaring the hell out of the post doc, which turned out to be lucky, because the fish was swiftly and safely returned to her tank.
As endearing as these fish are and as much fun as it can be to splash around in a fish tank, my sister isn’t studying the fish. She’s studying the creatures in the slime on their scales. Apparently, there are these rather alien invader looking cells that live in the slime covering the scales of these fish. The neat thing about these cells is that they crawl around in the slime.
Since nobody wants to do boring science, my sister is focusing on this neat crawling action. It’s even more interesting because nobody really understands how the cells manage to crawl about. Oh sure, they can talk your ear off about actin polymerization, myosin contraction, and the wobble the cells exhibit as they move inexorably towards their goal. However, they have no idea how they pick their direction. (Some other types of cells move up or down chemical gradients, but keratocytes do not.) So, how does the cell actually control it motion? Or pick where to head? Apparently only the cells know, and they lack high level communication.
So, Erin has to resort to experiments. For example, she’s interested in that wobble that the cells have. As they move, they tend to get a little off course, then, when they get far enough off course, they correct themselves and wobble a bit in the other direction. So my sister, being a good scientist, watches these cells zig and zag, wobbling about as they head wherever the chemical imbalance leads them. Watch one of these keratocytes wobble about in the movie below.
And like you, she wondered, “The hell with a little wobble, will the cells positively stagger if I get them drunk?” So, she adds various chemicals and otherwise tinkers with the medium, hoping to learn something about the internal workings of the cells based on their responses to environmental changes.
The little feller below is crawling along when my sister introduces him to the keratocyte equivalent of tequila. This really knocks him for a loop, but he eventually adapts and continues his crawl.
So what does this have to do with anything? Well, as it turns out, of the mammal cells that move, there is only that doesn’t crawl: sperm. All other cells, like white blood cells, crawl. It might be rather nice to have a better understanding of how the little things involved in wound healing and the immune system function.
Happy birthday Erin. I had a great time hanging out in California with you and Rick. I always have a great time talking geek with my sister.