ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Marishia Agard is an author on ‘ Another fly diuretic hormone: tachykinins increase fluid and ion transport by adult Drosophila melanogaster Malpighian (renal) tubules’, published in JEB. Marishia is a PhD Candidate in the lab of Jean-Paul Paluzzi at York University, North York, investigating how the endocrine system regulates salt and water balance in insects.
Marishia Agard
How did you become interested in biology?
I have always been fascinated by how different physiological systems interact with each other and how they affect various organ systems. Throughout high school and my undergraduate studies, it became my goal to investigate deeper into physiological systems in animals. This included taking courses and reading papers all related to physiology. I became greatly interested in endocrinology, specifically in the function of hormones and their ability to target tissues, thereby affecting the overall physiology of animals to maintain homeostasis. Now, I am fortunate enough to conduct research that involves investigating the role of diuretic hormones on the excretory system in invertebrates, such as insects.
Describe your scientific journey and your current research focus
I began my scientific journey during my third year of undergraduate studies at York University. I joined Dr Jean-Paul Paluzzi's lab as a research practicum student and worked with graduate students on rearing Aedes aegypti (mosquitoes). In my fourth year, I completed an Honour Thesis project on comparative neuroendocrinology by using fruit flies to study the role of neuropeptides in the Malpighian ‘renal’ tubules. My undergraduate research experience inspired me to pursue graduate studies to expand my research in invertebrate neuroendocrinology.
I am currently a PhD candidate at York University, working with Dr Paluzzi where my research investigates the role of the neuroendocrine system in coordinating the functions of the excretory system to maintain salt and water balance under different osmoregulatory challenges utilizing the fruit fly.
Conducting the ion-selective microelectrodes to measure ion concentration from the adult fruit fly Malpighian tubules.
Conducting the ion-selective microelectrodes to measure ion concentration from the adult fruit fly Malpighian tubules.
How would you explain the main findings/message of your paper to a member of the public?
Animals need to keep their body water content in balance, especially when dealing with different environmental stresses like desiccation. Insects, for example, use hormones to help maintain this balance. In our study, we looked at how a hormone called tachykinin affects the kidneys of fruit flies, known as the Malpighian tubules. We isolated the fruit fly Malpighian tubules and treated them with tachykinin to see how it affected the urine droplet formation and ion composition, compared to untreated Malpighian tubules. We found that tachykinin acts as a diuretic hormone, increasing urine production by interacting with a specific cell type in the fruit fly Malpighian tubules called the stellate cells. Additionally, we discovered that interaction of tachykinins with the stellate cells reduces the lifespan of the fruit fly during desiccation, showing its role in maintaining water balance in these animals.
What do you enjoy most about research, and why?
I really enjoy the journey of research. From the initial stages where we formulate all the research questions and plans for experiments to uncovering all the answers to the unknowns, which is so fascinating when all put together. You also get to collaborate with fellow researchers, which is super beneficial as you can learn new techniques to discover more findings. At the end of the journey, you get to share the research findings with peers in your research field. This all fuels further exploration and advances the discovery of scientific findings.
What do you like to do in your free time?
During my free time, I find it best to spend time with family and friends. It is important to enjoy these moments after a long day in the lab. I really like nature walks as it helps stimulate my mind. I have also taken up hobbies such as yoga and tennis to refocus and relax. It is essential to enjoy your free time, as it is crucial for recharging and maintaining a healthy work-life balance, especially with the demands of research.
Marishia Agard’s contact details: Department of Biology, York University, 4700 Keele St, North York, ON M3J 1P3.
E-mail: [email protected]
