The 33rd edition of Soup and Science, a popular Faculty of Science event showcasing the diversity of research being conducted at McGill, aims to provide students with an opportunity to interact directly with professors from different disciplines. Held remotely this semester, the mini-lecture series took place from Jan. 10 to 14. As always, we at the The McGill Tribune compiled some of the highlights of the week.
What can we learn about antibiotic resistance? A super close-up view of superbugs might help — Madhura Lotlikar
Since the first antibiotic was used on humans in 1910, antibiotics have saved hundreds of thousands of lives. Today, however, 700,000 people die every year due to antimicrobial drug resistance (AMR). The overuse of antibiotics in people, animals, and food agriculture has given bacteria the chance to evolve rapidly and produce proteins that make these antibiotics ineffective, thus leading to antimicrobial resistance (AMR).
In his talk, Albert Berghuis, a professor in McGill’s Department of Biochemistry, explained how bacterial resistance arose against Plazomicin—a three-year-old drug that treats complicated urinary tract infections (UTI). Plazomicin attaches to ribosomes—the protein-making machineries of bacteria—and inhibits protein synthesis, eventually killing them.
Unfortunately, Plazomicin’s chemical structure resembles that of many naturally occurring antibiotics which, millions of years ago, many bacteria evolved to resist. Berghuis and their team discovered that the 3D atomic structures of Plazomicin bound to ribosomes. Within the bacteria that contributes to UTIs, they also discovered an enzyme that alters Plazomicin’s structure, rendering it ineffective.
Identifying these 3D structures is a huge leap forward in designing drugs that can evade antibiotic resistance. Berghuis’ next step is to tweak the structure of Plazomicin so that the drug will eliminate the binding site of drug-resistant enzymes while still being able to bind ribosomes, thus preserving its effectiveness.
Governments and private funders are budgeting millions of dollars to develop more antibiotics, curb AMR, and save lives. The World Health Organization lists AMR under the top 10 pressing global health issues.
Computational and mathematical biology in health and disease – Zoe Karkossa
It is possible to describe cellular and molecular processes in the human body using a wide array of modeling and computational approaches. Anmar Khadra, a professor in the Department of Physiology at McGill, uses quantitative techniques to investigate the dynamics of a variety of physiological and biological systems, from cellular receptors to neural connections.
“Typically we use quantitative methods to conduct this research […] using two different avenues. One of them is developing mathematical models or biophysical models,” Khadra said. “Or we could develop computational techniques or algorithms that analyze the experimental data that we have, or even fit this experimental data to the mathematical models that we develop.”
An important theme of the work being conducted at Khadra’s lab is tuning into biological rhythms. For example, the recording and modeling of electrical activity of individual neurons allows for insight into the behaviour of ion channels. Rhythmic patterns can be detected through fluctuations in membrane voltage, interactions between different channels, and effects on hormone release.
“We do all of this type of computational work to make predictions, to validate mechanisms, generate hypotheses, test hypotheses, and […] generate the technological tools that could allow us to manipulate these systems,” Khadra said.
Our universe as a particle physics experiment – Adam Matthews-Kott
First discovered when the calculated mass of galaxies repeatedly failed to line up with the observed mass, dark matter has drawn interest and speculation from much of the scientific community. It was also the subject explored by Katelin Schutz, an assistant professor in the Department of Physics, in her talk.
“We have a huge amount of evidence for the existence of dark matter,” Schutz said. “We have evidence across nine orders of magnitude in length.”
Schutz went on to explain that dark matter is extremely pervasive in the universe, being five times more abundant than regular matter. This means that the majority of the universe is made up of a form of matter that humans still do not understand.
“We know how much of it there is by mass,” Schutz said. “We know it’s cosmologically stable, […] but most of all, we know it to not be accounted for by known physics.”
With this nebulous concept being on the front lines of scientific discovery, Schutz’ talk successfully summarized a complex topic that humanity still knows little about.
From soils to the Great Lakes: Tracing phosphorus in the environment – Jackie Lee
Following World War II, the rate of fertilizer production rose dramatically, and has only continued to accelerate since. The same is true for the use of phosphorus, an element essential to all living organisms, which agricultural producers often apply to conventionally farmed fields—with a generous hand—to ensure high yields and food security.
However, this agricultural enhancement has proven to be a double-edged sword, explained Christian Von Sperber, a professor in McGill’s Department of Geography. Phosphate fertilizer inevitably seeps from the soil into freshwater bodies, wreaking havoc on ecosystems through eutrophication, a process whereby an excess of nutrients prompts toxic algal blooms. The algae chokes aquatic ecosystems of oxygen, exterminating entire fish populations and contaminating drinking water, among other ecological consequences. Wetland restoration may offer a solution.
“They actually retain phosphorus and other nutrients and contaminants in the solids and in the biomass,” Von Sperber said.
His team is currently mapping and quantifying sources and sinks of phosphorus in both natural and rehabilitated land. They also look specifically at the prairie pothole region in Manitoba, whose unique topography allows for thousands of shallow wetlands.
“We’re thinking that the restoration of wetlands might actually be a nature-based solution to the problem of eutrophication,” Von Sperber said.
Beyond the context of phosphorus, wetlands also sequester large amounts of CO2, and are integral to wildlife.
“[Wetlands] provide a habitat for endangered species like waterfowl, or assistant professors and PhD students at McGill,” Von Sperber joked.
The Cytoskeleton – Madison McLauchlan
Students may know Gary Brouhard, a professor in the Department of Biology, from his fascinating BIOL 201 (Cell Biology and Metabolism) lectures, where he introduces large swaths of biomedical undergraduates to the micro-workings of the cell. In his brief talk, Brouhard gave a digestible overview of the main protein players in our cells and why it is so important that researchers investigate subcellular behaviour.
Brouhard started out with a simple question: If every cell in our body contains the same DNA, how is it capable of making cells with a myriad of different shapes, from the arborized structure of a neuron to the flat pancake of an epithelial cheek cell? Rather, what internal elements allow them to specialize and perform their functions so well?
“Just as the shape of an organism is determined by its skeleton, […] cells have an internal skeleton underneath their plasma membrane that determines their shape,” Brouhard said. “We refer to this as the cytoskeleton.”
One component of the cytoskeleton are microtubules, cylinder-like polymers that flare out at the ends, assembled from individual proteins. They are constantly breaking down and reforming, lending these structures versatility in their function: Not only are they important for maintaining cell structure, but they also help form the mitotic spindle during cell division and even act as “cellular highways” to transport materials to key locations in the cell.
“[Proteins] assemble like magic lego building block[s] into this long structure, and that is how cells can reorganize their microtubules,” Brouhard explained. “[Cells] can break these tubes down, and rebuild them in different places.”
Beyond the basic research importance of Brouhard’s lab work, this domain has implications for understanding human health. Malfunctions in key proteins linked to microtubules, like doublecortin, have been associated with diseases such as type 1 lissencephaly, or a condition called “smooth brain syndrome” where the cerebral cortex is missing folds. By observing the behaviour of microtubules in the lab, researchers can understand what patterns are leading to disease phenotypes.