This summer, I had the privilege of working with the Mourkioti lab on characterizing the steady-state conditions of muscle stem cells. Muscle stem cells play a major role in muscle regeneration. Many muscle diseases, including Duchenne muscular dystrophy, are associated with stem cell dysfunction following continual cycles of injury and repair. Following muscle injury, muscle stem cells become active, proliferate, and fuse with the surrounding tissue, allowing for complete regeneration within a few days. Pax7 is a marker of muscle stem cells that is conserved across many species, including humans. To look at live muscle stem cells, our lab generated a Pax7EGFP mouse model by inserting an enhanced green fluorescent protein (EGFP) cassette in the Pax7 gene. This allowed for the expression of EGFP driven by endogenous promoter and regulatory elements. Using two-photon microscopy, we were able to visualize muscle stem cells for the first time in vivo and then analyze them for their characteristics under steady-state conditions.
Throughout my research experience, I greatly enjoyed witnessing how concepts I had learned in the classroom, such as cell differentiation, fluorescent proteins, and transcription factors, are actively being used in research labs to tackle real-world questions. Not to mention, I was able to build immensely on my classroom knowledge, learn genotyping, cell culture, and imaging techniques, as well as better appreciate the mind-bogglingly complex world that researchers seek to elucidate. I am so grateful for my experience getting to participate in an engaging research community, and I look forward to continuing my project in the upcoming months, when I will use the data I have gathered thus far to examine how muscle stem cells change under injured and diseased conditions.