Hi, I’m Faith! This is my first year in college, and I’m the new kid in the Lizard Lab. I have never worked in a lab before or even touched a lizard, so this is very new and exciting for me. One day I’ll have my own project, but for now I am learning and helping Michelle, another student in the lab, with her research. (You can see a picture of Michelle and me working together above.) We are looking at lizard arm muscles so we can better understand how they move. Some lizards don’t move a lot, but when they do it happens in short, quick bursts. Other lizards move all the time, but at a very slow pace. We want to know why!
The first step of our study is to catch the lizards and get samples of their muscle fibers. Once we have the samples, we go back to the lab, cut the muscles into very thin slices, and place them on slides so we can look at them under a microscope. The samples are way too small for us to view closely with just our eyes!
Next, it’s staining time! We use one stain to measure how many cells in a muscle can make it contract quickly (these are “fast twitch” cells), and how many contract slowly (or, “slow twitch” cells). The slow twitch cells don’t have a lot of force, but it takes a long time for them to get tired. We use a second stain to measure how fast the muscle cells can make energy. These stains make different kinds of muscle cells have different colors – some are really dark, while some are really light.
After the two stains are complete, we get to use the microscope to count the cell types. We look at each fiber closely and take pictures of the cells. For each muscle, we put the pictures of the two stains right beside each other. Now it’s all one big matching game! We pick one cell on the first picture and then we have to hunt down the same cell in other picture. We have to look at 50 cells for each muscle to count the types of cells in that muscle.
We use our cell type data to test our prediction that lizards that use fast movements have muscles with lots of cells that contract quickly, and lizards that use slow movements have fewer of these cells, but more slow twitch cells.