Studying the Site Specificity of Spastin: Subject for Speculation

This summer, Shibani and I are working in the lab of Dr. Nina Tang Sherwood studying the spastin gene, which plays a role in microtubule severing. With a long history that began in 2004 when Dr. Sherwood’s lab identified the gene in a screen, the specific site of action of spastin is yet to be discovered. Previous studies consisted of ubiquitous mutation of spastin, which means every cell in the body had spastin missing or knocked down. Dr. Sherwood found that spastin null fruit flies have bunched, irregular synapses in the neuromuscular junction along with reduced motor function and lifespan (2004). However, we don’t know if this result was caused by the knockout of the gene in neurons, glia, or if it has to be ubiquitous to see this phenotype. Therefore, one of our projects is to determine where this deletion really matters in order to find the site of action of spastin!

To determine this, we have to make a bunch of complicated crosses. In our self efficacy program on Wednesday, we were asked to write a challenge that we needed to overcome in the lab, and I chose understanding crosses. I am happy to say that the next day I was designing my own crosses on the white board with Shibani! What is so complicated about these crosses is that you need so many factors in the final product and multiple lines to get to your desired outcome. What will set our final lines apart will be the tissue specific drivers, which make sure your mutation is only in the tissue type you want. We plan on using glial specific drivers, neuronal specific drivers, and ubiquitous drivers. Our next step will be to look at the neuromuscular junctions by dissecting larva! 

My first day of practice dissections was rough, and if I try to dissect for too long, I start to feel sick to my stomach. Dissections are especially difficult since larvae are tiny, so we have to use tiny scissors and dissect under the microscope. The hardest part for me is pinning the larva down, because the pins can slip in my forceps. However, after a little practice each day for a few days, I have strongly improved my dissection and am ready to do the real thing! After comparing the glial, neuronal, and ubiquitous knockouts, we hope to learn more about where spastin functions. I’m already proud of the progress Shibani and I have made with the support of Dr. Sherwood, and can’t wait to see where our project ends up!

My first dissection (left) vs my most recent dissection (right)!

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