Mahmoud El-Saadi, M.Sc Candidate, Environmental Physiologist

Hello! My name is Mahmoud, a master’s student at Carleton University in Ottawa, Canada. After completing my undergrad at Carleton, I stayed to pursue an M.Sc in Biology in Dr. Heath MacMillan’s lab.

What is your favorite part about being a scientist and how did you get interested in science in general?
I would say my favorite part of being a scientist is the constant excitement of asking questions and having the freedom to try things out. In a constantly changing world, new evidence is always popping up which can occasionally change the way we look at pre-existing theories and data. I really enjoy meeting other scientists and bouncing ideas off of them, as well as communicating science to people.   

As for my interest in insects, it started with an upper-year biology course on insects which involved going out and collecting different species of insects. I was hooked after the course, in large part due to simply appreciating how diverse these animals are in their biology. The world of insects is massive!

What is your research about?
My research is currently looking at how insects are injured by low temperatures, and if there is any connection to their gut. The majority of insects, such as flies, locusts, crickets, and bees to name a few, do not do very well at low temperatures, and this can result in them becoming injured or dying. The exact driving forces behind these injuries are not exactly known, but they are thought to be driven by water and ion balance becoming dysregulated due to the insect’s gut losing most of its ability to control water and ion flow between the inside and outside of the gut. However, similar to us, insects also have a diverse community of bacteria in their gut! This leads me to my main question: if insects suffer injuries at low temperatures, is that partly because gut bacteria are finding their way outside and into tissues? If that is the case, then the resulting infection could be another factor behind the tissue damage which would provide better insight as to why most insects cannot handle the cold very well.

What are your data, and how do you obtain them?
To see if low temperatures lead to bacterial leak from the gut, I am feeding a fluorescent strain of E. coli bacteria to locusts, my model insect of choice. After they eat the bacteria, I expose them to a low temperature and extract a sample of their hemolymph, or “blood”. I then place the hemolymph in agar gel plates that allow any bacteria to grow overnight. I would then confirm the presence of the fluorescent bacteria by shining a UV lamp on the plates, which would show a strong yellow fluorescence. If bacteria are finding their way out of the gut, then I would see the fluorescent bacteria in the plates.

A unique strain of bacteria that emits a yellow glow under an ultraviolet lamp.

How does your research contribute to the bigger picture?
When it comes to the spread of insects across the globe, their ability to handle low temperatures is a very strong predictor for their survival and distribution. In other words, insects that are better able to survive cold environments are more likely to spread further than insects that are less able to survive the cold. This is particularly important when it comes to the issue of climate change, as greater and more frequent extremes in temperatures can expose many insect species to a different environment than what they are normally used to. In the context of pests that may damage agricultural crops, trees in forests, and pose a risk to our health, knowing how insects are physiologically affected by the cold can provide valuable information that we can use to predict their movement and future distribution. I would say that my work is just a small piece of the much grander puzzle of why insects do not like the cold!

What advice do you have for aspiring scientists?
The advice I always give aspiring scientists is to never be afraid to ask questions. In a way, asking questions is what defines us! If you are an undergraduate student in STEM who is interested in research, try to take the first step to email a professor if you are interested in their work, because that first step can definitely go a long way. No matter your research background or experience, there is a field out there for everyone. Embrace your passion for science and go forth!

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