WHAT THEY LEARNED: Alana Engelbrecht and Sarah Waldis

The biology majors collaborated on related senior thesis projects on the role of fruit fly genes in mosquito embryo development.

Sometimes in the natural sciences, thesis topics carry over from year to year as a new group of students grapple with questions central a specific professor’s lab. For example, Associate Professor of Biology Rachel Hoang studies morphogenesis, and students in her lab explore how cells change during embryonic development using fruit flies. And two of her students, Alana Engelbrecht and Sarah Waldis (both Class of 2016), collaborated on related projects that picked the thread of work done by Hoang’s previous students.

“We chose an ongoing project that had already made some progress in answering its central question,” says Engelbrecht, who is looking towards a career in public health. “A lot of our work involved improving procedures for the next students picking up the project.”

That question involves the role of two fruit fly genes in the early development of the mosquito embryo.

“The fruit fly and mosquito are closely related, so eventually this kind of comparative analysis could help to shed light on how some of the most critical mechanisms of embryonic development evolved,” explains Waldis.

Though the two women wrote separate theses—Engelbrecht’s was “Investigating the role of Drosophila melanogaster genes t48 and mist in Anopheles gambiae gastrulation” and Waldis’ was “Understanding the role of twist and fog in Anopheles gambiae gastrulation”—their work was closely linked, and the collaboration and cooperation they provided to each other was a key component of their work.

“This project taught me a lot about how valuable collaboration is to scientific research,” says Waldis, an aspiring developmental pediatrician who is currently working in a lab at Children’s Hospital of Philadelphia. “Alana and I often talked through obstacles and successes together and came to conclusions I don’t think either of could have come to alone.”


What did you learn from working on your thesis?

AE: I really enjoyed learning about the subject matter of our field of research, embryonic development, as well as about the lab techniques that we performed that I hadn’t had experience with beforehand. I also found learning about the research process itself to be very interesting! There are so many subtle nuances to completing a research project that you wouldn’t even think about before being immersed in it yourself.

SW: One of the biggest takeaways I have from my thesis experience is a deeper appreciation for the creativity inherent in the scientific research process. Because our thesis project involved a less well-studied organism—the mosquito—a lot of our work revolved around designing experimental protocols so that data could be collected. We frequently would search for protocols used with better-studied organisms—like the fruit fly—and then find ways to optimize those protocols for the mosquito. Along the way, we had to brainstorm how to tweak and adapt each step to better suit our purposes, and all of those small but really important adjustments relied on thinking outside of the box. I think that skill of taking a problem and thinking about it from many different angles will serve me well as both a future researcher and physician.

What are the implications for this research, and how could it help other researchers going forward?

AE: Our research is most directly relevant to the field of embryonic development. We aim to better understand the role of certain genes in the development of the mosquito Anopheles gambiae to advance our understanding of the evolution of animals’ most basic yet essential molecular mechanisms. These genes that we know are in the fruit fly Drosophila melanogaster are, as of yet, completely uncharacterized in Anopheles gambiae, and their existence is actually not established in any published literature. The Hoang Lab is, therefore, doing some incredible pioneering work for the field of evolutionary embryonic research! The molecular mechanisms involved in this work are also more broadly related to the cellular movements during cancer cell metastasis, formation of aspects of the central nervous system, among other critical biological functions. Our research would, therefore, help us better understand how these processes have developed and changed over time. Since mosquitos spread diseases such as malaria, Zika virus, and dengue, targeting the genes involved in these early developmental stages could help control their spread.


“What They Learned” is a blog series exploring the thesis work of recent graduates.

Photo by James Gathany/CDC