Mitochondria (green) in the distal dendrites of a neuron (pink) of the fly visual system. Photo credit: Avi Adler
Around campus, when chatting research, I often say that my hours in the lab are spent “messing with flies.” While this is perhaps a stretch, it is not far from the truth. Most days begin with fly work: the necessary housekeeping of working in a Drosophila biology lab. Although I started using this line with a good sense of humility, to my own surprise my peers in the classroom, dining hall and various social events are sincerely intrigued by it. When pressed further, I explain my expertise in sorting flies by their eye color, wing shape, hair length, etc. This usually leads to a tangent about genetics, and naturally a comment about ordering flies from Bloomington, Indiana. After I’ve thoroughly explained how to mate flies such that the next generation of flies has red eyes and not curly wings, I am usually then asked what I am actually researching.
Over the past few semesters, I have had the incredible opportunity to study not fruit flies, but mitochondria. My project has focused on mitochondrial turnover: a necessary and vital mechanism that helps cells maintain a stable, healthy population of mitochondria in every cell. Although essential, the dynamics that control it are not well understood. To better understand this process, and specifically how it fits into the larger picture of cell-homeostasis, we utilize fruit flies. My lab, the Barnhart lab, is a hardcore Drosophila (fruit fly) lab (big surprise!). Everything we investigate occurs in-vivo(“within the living”). We study various factors and proteins that govern mitochondria in live, living fruit flies. To investigate basic biological processes, these are the ideal model organism; from extreme genetic mailability, to easily trackable life cycles and ages. While it is unquestionably more challenging to study intracellular dynamics in organisms themselves (even fruit flies), the results one draws are insightful and often more telling that experiments that occur outside a living, breathing system.
To gain insight into the life and times of mitochondria, one must first illuminate them—literally. To do so, my lab has developed a technique by which we dissect out the brain of a fruit fly. Utilizing grade-A tweezers, especially sharpened for our purposes, the bulk of my day is often spent staring down a microscope carefully pulling out the brains of fruit flies. If successful, I then must follow a complex and exact set of steps to ensure the precious mitochondria (what this whole thing is for, anyways) do not degrade. After subsequent baths in formaldehyde, goat serum, and antibodies (ironically often made in goats), the brains are ready for the microscope, where the fluorescence truly begins.
The first lesson in confocal microscopy is that one must have the microscope objective within a fraction of a millimeter of the sample—yet never touch it. After my heart briefly stops as I lower the objective, the brains are ready for fluorescence. As the lasers go on, the mitochondria (tagged with a fluorescent protein) begin to shine, and the fruit flies fade into recent memory. This is the first moment when remember I am studying mitochondria. As the images themselves turn into data, the flies become figments of the past.
Just as fruit flies are essential to our study of mitochondria, they are equally so a path to discussing cell biology in just about any conversation, a skill I’ve honed and become particularly fond of. These conversations have become a moment of inflection as I realize someone formerly unengaged in any scientific pursuit has suddenly become interested—because of fruit flies. They are amongst my favorite points of conversation exactly for this reason: they are engaging and insightful in both my world of mitochondria and the greater campus community.