Student Spotlight: Dmitrii Krivorotko’s Zebrafish Research in the Talbot Lab

In March 2021, the Institute of Medicine (IoM) at the University of Maine requested proposals in the areas of health and life sciences for a seed grant program meant to support the goals and objectives of the institute.  This grant program required two or more full-time UMaine or University of Maine at Machias faculty to work together on a pilot project aimed at collecting preliminary data as proof of concept, leading to the submission of a related significant proposal by July 2022.

The awarded projects included:  “Advanced imaging of muscle fiber development” led by Jared Talbot, an assistant professor of developmental biology.  One of the students involved in the project,  Dmitrii Krivorotko, shared his experience doing research and completing his honors thesis while in the Talbot lab. Dmitrii graduated in May 2022 with a BS in Biology.

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For my Honors project at the University of Maine, I completed a year-long animal research project in Dr. Jared Talbot’s biology research lab. I had met Dr. Talbot through his Histology class, which I took in spring of 2021. I was excited to join his lab because his course was driven by questions – he taught us that there is no final answer to a question, but we can always keep digging to learn more than was known before. Last summer, I reached out to him, wondering if he would be interested in taking me to his lab for the thesis project. He invited me for an interview and told me about recently developed animal models that lack function of fast-contracting muscle types (fast-twitch muscle).

This animal is a zebrafish lacking function of two Mylpf genes, mylpfa and mylpfb, which have direct clinical relevance, because human MYLPF mutations cause a developmental disease called Distal Arthrogryposis. Mylpf protein is thought to stimulate muscle contraction by binding and stabilizing myosin proteins in fast-twitch muscle. This stabilization is important for the production of sarcomeres, which serve as the basic unit of muscle structure, however, the physiological effects of Mylpf gene knockout have been poorly studied to-date. In the summer of 2021, Jared Austin, a technician in the Talbot lab, did pilot analysis of spontaneous behaviors in Mylpf mutant zebrafish, and I picked up this project when I joined the lab. I completed 21 Trials of movement imaging so I could investigate what ranges of velocities each genotype group of zebrafish swam the most frequently at on their own. By combining my data of 149 fish and analyzing over 6 million data points, I differentiate between the velocity ranges that correspond to slow-twitch muscles and fast-twitch muscles in zebrafish. Surprisingly, I found that zebrafish can compensate for a lack of fast movement by increasing their slow-twitch behaviors. Such compensation suggests a mechanism to potentially restore movement in utero and prevent diseases like Distal Arthrogryposis, and the Talbot lab is interested in pursuing this possibility through future research.

During the school year, I spent around 20 hours per week working on this project. I have continued to work on it over the summer – but I could only succeed in these experiments because of training and support from Talbot lab members. For instance, Jared Austin taught me how to analyze zebrafish behavior, and provided a solid set of initial observations. Emily Tomak, a graduate student, coached me throughout the year, taught me how to genotype animals, and when I was running short on time, she genotyped many animals for me. I am also grateful to Henry Lab for the access to DanioVision and the support through my project and to my thesis committee for their support of my project. In particular, I would like to thank Dr. Talbot for his direct support. We had hour-long weekly meetings during my second semester, which he also held with each of the seniors in his group. We had productive conversations about my ongoing experiments, and he also dedicated himself to listening and truly understanding the struggles that I was going through both inside and outside of the lab. Through this training, I was able to elevate my research and writing until I felt that it is on par with a graduate student. To say that I appreciate Talbot Lab would be an understatement, as this experience has changed my life and truly boosted my ability to think and solve problems to levels that I would not reach without Dr. Talbot and my peers. I am also grateful to my thesis committee, for providing me guidance and awarding my project with Highest Honors.

I believe that the hard work that I have put in the lab has prepared me for future obstacles in my career. While being my project advisor Dr. Talbot has also provided tremendous support and guidance during my application process to grad schools. I am happy to say that these applications were successful; I was accepted to Boston University for the Master of Public Health program.