Previous Research
Graduate School Rotations
In the first year of graduate school, students rotate in three labs for ~6 weeks each. At the end of the school year, the student selects a lab to reside in during the duration of their PhD.
I am rotating in three different labs in the Biochemistry & Cellular and Molecular Biology department.
1st Rotation: Lab of Dr. Gladys Alexandre - Chemotaxis in the nitrogen-fixing bacteria Azospirillum brasilense
2nd Rotation: Lab of Dr. Francisco Barrera - Biophysics and cell biology of lipid membranes
3rd Rotation: Lab of Dr. Brad Binder - Ethylene signaling in plants and microbes
Flocculation Behavior in Azospirillum brasilense and it's Connection to Chemotaxis
October - December 2019 | University of Tennessee, Knoxville
For my first rotation in graduate school, I chose to work with Dr. Gladys Alexandre. Her lab studies a bacterium called Azospirillum brasilense. This bacteria forms a symbiotic relationship with plants in the rhizoshpere by fixing nitrogen for the plant in exchange for sugars and organic acids. The lab studies the motility strategy of this bacteria, but that can mean many things. Bacteria don't sense their environment like humans do, so they require different machinery to evade toxins and find food sources.
My project focused on a specific behavior that A. brasilense executes called flocculation. Flocculation is a common behavior in bacteria that is characterized by a decrease in motility, change in cell morphology, and secretion of extracellular polysaccharides and proteins. In A. brasilense, flocculation is triggered by metabolic stresses, like increased aeration and altered carbon/nitrogen sources. I'm trying to find a way to quantify the physical "floccs" that A. brasilense generates and then seeing if different chemotactic mutants vary in their flocculation behavior. This could potentially help elucidate which set of chemotactic genes control flocculation, which could lead to insight of how A. brasilense colonizes the roots of plants.
Understanding the Phosphorylation of a Putative Ethylene Receptor in Azospirillum brasilense
February - May 2020 | University of Tennessee, Knoxville
I rotated in the Binder lab for my last rotation during my first year. Having worked in this lab before (see below), I was excited to see what I would be able to do during my time here having learned so much more since summer 2018. The Binder lab studies ethylene signaling in plants and microbes. Understanding this mechansm is important due to the role that ethylene has in plant growth and development, and thus agriculture. The ethylene receptor in Arabidopsis thaliana is well characterized, but recently a homologous receptor that binds to ethylene in Azospirillum brasilense has been discovered (AzoETR1). ETR1 contains a histidine-kinase (HK) domain that resembles two-component signaling systems in bacteria, which are responsible for signal transduction into the cell. Originally, my goal for the rotation was to establish an assay that would characterize the phosphorylation behavior of AzoETR1. However, I did not go back into lab after March 13th as the Covid-19 pandemic shut down non-essential research. I spent the rest of my rotation writing a reveiw about ETR1 and it's signaling abilities (which can be found in the "Presentations and Publications" tab.
Undergraduate Research
Characterization and Quantification of Fibrinogen and TLT-1 Binding Properties
January 2017 - May 2019 | Maryville College
I began working under the guidance of my advisor, Dr. Angelia Gibson, in the January of my sophomore year of college. At the moment my career goal was to attend medical school and become a Physician, and getting research was just going to be another notch on my application. After working on this project for less than a year, I changed my career direction towards Academia and Research in Biochemistry.
Our lab studies a small platelet protein called TREM-Like-Transcript-1, or TLT-1 for short. This small protein mediates platelet aggregation, affects bleeding times in mice, acts as a bioindicator in the progression of Sepsis, and interacts with many coagulation factors in the blood. This brings me to the goal of my research, which was to characterize and quantify the binding relationship of TLT-1 and Fibrinogen, the zymogen of Fibrin (which makes up the mesh-like network of a blood clot). This project eventually became the topic of my senior thesis, a requirement for graduation from Maryville College. I used Fluorescence Spectroscopy and Co-Immunoprecipitation to study the binding properties of these two proteins. Another aim of my thesis, which I acquired quite the fancy for, was to optimize a method for purification in our laboratory. Previously, we were sent TLT-1 from our collaborators in Puerto Rico. Now we have the capabilites to purify TLT-1 in house using a traditional purification method utilizing IMAC for purification.
Laboratory Skills
> SDS-PAGE
> Western Blotting
> Fluorescence Spectroscopy
> Immunoprecipitation
> Protein purification
> Plating and maintenance of bacterial cell culture
> DNA Gel Electrophoresis
> Histology
> Protein Assays
> Microscopy
> Microdissection
Software Experience
> Microsoft Office Suite
> JsMOL
> Expasy
Characterizing the Ethylene Receptor in Azospirillum brasilense
Summer 2018 | The University of Tennessee Knoxville
After having over a year of research experience under my belt, I wanted to spend the summer before my senior year doing something that would hopefully help my career move forward (and boy did it). After my advisor graciously reached out to her colleagues from her alma mater, UTK, I connected with the Binder Laboratory and conducted research on the ethylene receptor found in Azospirillum Brasilense, a bacteria found in soil known to help plants grow. Ethylene is a gas that acts as a plant hormone to promtoe processes like growth and fruit ripening. The ethylene receptor in the common model plant, Arabidopsis thaliana, is well characterized. Recently, a homologous receptor has been identified in soil-residing bacteria and could, hypothetically, perform a similar function in bacteria, aid in the understanding of the symbiotic relationship between plants and soil-residing bacteria, and could even elucidate an evolutionary link between plants and their bacteria.
My work involved a lot of buffer and media preparation, bacterial culture maintainence, and western blots. I did much work under the guidance of a graduate student who showed me many DNA methods that I was not acustomed to. I gained experience in DNA gel electrophoresis, PCR, and Genome Sequencing. I also got to learn about plant-based biochemical research as well as getting insider information and advice about being a Graduate Student.
Histological and PAGE Analysis of Xenopus laevis Tadpole Eyes
Spring 2019 | Maryville College | BIO 414
In one of the last science courses I would take at Maryville College, Developmental Biology, our last lab project was a group project of which we were able to pick a topic, but it had to be based around an environmental contaminant that would affect an organism's development. My group based our study on an old senior thesis that examined the effects of UV radiation on the histological structure and protein composition of zebra fish, Danio reriro. Our class had an abundance of Xenopus laevis tadpoles, so we did a similar study on that organism. The assignment involved a project proposal, experimental design, and a final presentation of our results.
This project was special to me because I was able to use two techniques that I had fallen in love with over the course of my college career, SDS-PAGE and histology. I had been doing SDS-PAGE for years in my TLT-1 research, but histology was a technique I learned the previous semester in a similar course taught by the same professor. Histology is a technique that involves a lengthy process of preparation, maticulous and detailed hand work, and qualitative analysis.
This project was not only a testament to the variety of lab techniques that I was exposed to in undergraduate, but also a confirmation of how anthropogenic impacts are detrimental to our natural world. UV radiation is not something that humans create, but the amount that we are exposed to is perpetuated by our production of atmospheric greenhouse gasses and destruction of the O-Zone layer.