Category Archives: BSURF 2017

Blogs for the Biological Sciences Undergraduate Research Fellowship 2017

I never realized bird songs could be so interesting…

I have to say, the seminars have been incredibly interesting and a great start to my mornings. I like that we have been able to listen to a wide breadth of science being done a Duke and learn about all different types of fields and research being done. In our labs, we have been getting a very in depth look into one subject, but through the seminars we have been able to learn about all different types of research.

One of my favorite seminars was on something very unexpected: bird songs. Dr. Nowicki studies how birds communicate and how their songs evolve, and then uses birds as a model system to better understand human language and communication. This lab does not relate to anything I am studying and the field work they do is pretty different from the bench work I do in the lab every day. Quite honestly, I really did not think that bird songs could be very interesting. However, I walked out of Dr. Nowicki’s talk suddenly incredibly interested in bird songs! The way that Dr. Nowicki presented his research was engaging and easy to understand, so I felt like I had a good idea about what was going on in his lab without being overwhelmed. Additionally, I was interested in learning more.

All the talks have been incredibly interesting and got me thinking about all the different types of research out there. I do think the most influential parts of the talks, though, were the parts where the faculty told us about their career journeys and how they got to where they are today. Those stories really gave me a good understanding of what my career path may look like if I choose to go to grad school. They also let me know that there are many ways to get to the same place, and let me know that there is still time for me to figure out what I want to do in the future. Doing lab work right now is really awesome for whatever I may choose to do, but I still have time to explore my interests and find my path.

Looking Ahead

All summer we’ve had the opportunity to meet and learn from distinguished faculty which was super cool. One of my favorite talks I think this summer was from Dr. Christopher Kontos. Dr. Kontos is the director of Duke’s MD-PHD program. I really enjoyed this talk because before the program I was really contemplating striving for a MD-PHD. Listening to him talk really opened my perspective about everything. Especially because I work in a lab where people have all different types of academic backgrounds I think I’ve learned a lot! I really appreciated this talk because we got to ask lots of questions and learn more about the program. This has allowed me to explore my future even more which I was thankful for as BSURF comes to an end.

Science with a Story

Throughout the program we’ve had the opportunity to hear from a variety of researchers at Duke. They have studied everything from CRISPR to bird song varieties, but have all shared one thing: their passion. Everyone who spoke had a clear passion for their work and a true love of science. It was inspiring to hear how so many people made successful careers for themselves that include their personal interests of discovery and innovation.

One talk that really struck me was from Dr. Anne West. Dr. West’s research was interesting to me from the start because it is in my intended field, but she also delivered such a powerful presentation on the importance of basic science research. Her presentation talked about the serendipity of finding CRISPR in archaea in the 1980s and how that discovery has led to a massive revolution in research today. Those findings will be able to alter medical treatment for a myriad of diseases, including Duchene’s Muscular Dystrophy. Dr. West made a convincing, easy to follow, and powerful case for funding basic science research. She communicated with the audience in a way that many people would relate to, by bringing up how a disease affected a child. She gave her audience hope at the end, a clear understanding of how basic science research that was completely unrelated to a disease could become applicable to its treatment, and she did it all without using scientific jargon. I was impressed with her project idea and her future plans to collect these stories and turn them into a book. Her ability to use research that she was working on, science that she knew, personal experiences that she had, and an opinion that she believed in all at once was impressive. I was already planning on getting a Science and Society certificate from Duke, but now I might have an avenue by which to pursue my interests in conveying the importance of science to the general public. I hope that Dr. West’s project turns into a book that educates the public and our politicians about the importance of basic science and how drastically basic science can impact our society.

“I’m Squawkin’ Here!”: The New York Accent of the Bird World

Dr. Stephen Nowicki lied to us. While I’m not a fan of lying, this lie was ~for science~, which made it acceptable. This lie, while small in size, made a big difference. The difference was between “pa” and “da” – a miniscule change of breath. This difference, clear to us, shows our categorical thinking: something is “pa” because its not “da”. Birds also, amazingly, display categorical thinking in their song. If it is not the correct song, the song has no meaning, just like how saying “dause” means nothing to humans (while the word “pause” makes sense). Birds from Pennsylvania do not understand the songs of birds from New York because of these slight changes (who knew birds had accents?). Throughout the faculty seminars this summer, I have noticed a trend: discovering connections in the world. I thought Dr. Nowicki’s research was incredibly cool because it uncovered more interconnectedness in the natural world. Additionally, I have been working in an animal behavior lab and Dr. Nowicki’s research sparked my interest into another side of animal behavior research I had never seen before!

“Why do you do science?”

“To learn stuff…about the world.”

That was the first answer to Dr. Kathleen Donohue’s opening seminar question, given by yours truly. A soft round of chuckles rippled backwards through the seats of the classroom and I lowered my hand sheepishly. Okay, not my most eloquent response given that it was early morning (aka 9am) and I was still processing the much-needed sugar provided by some granola bars.  But still, that was basically the summary of the excited pull I felt in my gut when considering Dr. Donohue’s question. After all, learning new things about the world around us constitutes the very core of science, right?

However, as Dr. Donohue called on other BSURFers, people began giving answers like, “to find cures” or “to solve x problem in society.” Oops. I mean, those are really important too, but I’d be lying if I said they were the first things that came to mind. I felt slightly ashamed. Was I being selfish and, more importantly, impractical with my intentions in research?

It turns out, at a recent convention Dr. Donohue had asked several hundred evolutionary biologists the same question…and many of them had sided with pure curiosity. Dr. Donohue explained that whether you are in basic or applied sciences, it is vital to have the desire to learn things for the sake of learning things, because this is what motivates scientists on a daily basis. “You could be searching for the cure for cancer,” she said, but you’re not going to find it in a single day. Your curiosity and investment in your current tasks, even if what they reveal isn’t the game-changing discovery you ultimately hope to make, is what will carry you in the long run. In other words, pure curiosity is what sustains people who can work years and years on something, and then finally come up for a solution to an important problem. When I heard Dr. Donohue’s words, my shoulders relaxed in relief, and I felt a glimmer of happiness and hope. So I wasn’t going crazy: doing science simply to learn things about the world wasn’t such a bad thing.

However, Dr. Donohue also reminded us of the reality that, while curiosity may motivate scientists, practical applications are what interest most of society—including many funding organizations. So it’s really important to be able to communicate the value of your work to non-scientist contacts. That’s when Dr. Donohue said something that struck me: “whomever you are talking to is perfectly capable of understanding you, if you are perfectly capable of communicating to them.” Communicating science needs to be a dialogue: you need to know what the other party cares about, what they already know (or think they know), what their concerns are, and more. If you know this, you’ll know what to say and do in order to engage them in your work. This was good food for thought for me, because I’m interested in communicating science to the public but am sometimes unsure how to go about it. Understanding where the other party is coming from, and integrating these insights into how I explain science, is a tactic I’ll be keeping in the forefront of my mind from now on.

I know a major aspect of these faculty seminars is learning about each scientist’s specific research topics. But honestly, I think that Dr. Donohue’s more general discussion about the nature of scientific research and communication made one of the strongest impacts on me. It didn’t just reassure me that curiosity still plays a key role in driving science forward, but also acknowledged that the desire for practical solutions cannot be ignored and must also be satisfied. I think a good scientist has to be able to balance both of those motivations when doing research, and I hope that’s what I’ll be able to do in the future.

Happy Accidents

Happy accidents are those moments of sheer luck and coincidence in life that we’ve learned to cherish whenever they should pop up. We don’t really think about them though. We never take the time to reflect on them, to think where we might be in life should they have never occurred. Dr.Mohamed Noor made me think critically about happy accidents and for that reason I’d like to talk about what I gathered from his talk.

Dr.Mohamed’s talk woke me up from a deep sleep. Literally. I was face-down on the table when he walked in rambling about evolution and genetics. He went on to give a riveting talk about his path he followed as a scientist, the theory of evolution in the context of today’s society, and his own work. As a group we discussed possible solutions for communicating the theory of evolution to lay audiences in a way that they could be receptive to. He played us some example recordings of fly courtship ‘songs’ that were part of some of the work hs has done in speciation. However, the part about his talk that I really resonated with was the happy accident that occurred during the research project he was undertaking during graduate school.

Dr.Noor told us about amazing data he was able to produce during a graduate project that put him in the spotlight as an evolutionary biologist. He discussed it with humility and humor as he described how the amazing results were almost all sheer luck, a happy accident if you will. I found it interesting that Dr.Noor was so open about this. Where would he be if it hadn’t been for this happy accident. Would I be calling him ‘Dr.’ today? If someone had not sent me a snapchat of the Duke application two days before it was due, would I even be here today? I don’t have the answers to these questions or how my life would be different today but I do know it doesn’t matter. I’m so grateful for having been able to follow the path that I was set on by a trail of happy accidents. However, even if I hadn’t been ended up at Duke and at this program I would still know my future lies in science. I would have come to this realization in some other way in some alternate timeline. The paths we follow and the lives we live can seem so haphazard and random but what we can control is what we feel and know on the inside. No happy accident can change that.

Breakfast Tunes

As I mentioned in a previous blog post, my schedule revolves around my meals. To me, seminars primarily mean the time of day where I drag myself up ten million flights of stairs to French Family and finally get to reenergize with some granola bars, fruit, OJ, and yogurt (thanks for the new yogurt, Jason!)

While I love having seminars because it means getting to eat, there’s an added bonus of going: learning about other research that faculty members are doing. The seminar that struck me the most was Dean Steve Nowicki’s. Steve is my academic advisor, and I’ve heard a lot of his stories including his research. I’m not sure if it’s because I wasn’t eating when I first heard it, but I never fully understood the research he was doing until he came and presented to us — and wow am I glad I finally understand it!

Steve’s research investigates how birds communicate using various biological approaches. After taking genetics and evolution in the Spring, I was able to have the capacity to fully understand his presentation. It was amazing how he was able to connect how birds learn to communicate with humans. One anecdote that he brought up was the inability to hear certain phonemes and growing up bilingual, I completely understood. I remember my parents trying to pronounce Walmart and not being able to enunciate the l’s and the r’s.

Another interesting point he brought up was the difference between songs of birds from Pennsylvania and New York. I asked a question about how this affects mating, and Steve said that birds in Pennsylvania won’t even recognize the songs of birds from New York. This led me to think about how the Biological Species Concept is applied. If females won’t pick up the courtship songs of males, when are the regional birds considered different species?

Coming full circle

One of the faculty talks that stood out the most to me was Dr. Charles Gerbasch’s talk. After his talk I realized that his name had sounded pretty familiar. It then hit me that back when I was researching universities to attend, Dr. Gerbasch’s lab had struck my interest back then as well. Research like his had been one of the reasons I later decided to attend Duke.

One thing that really stood out to me about Gerbasch is that he places a strong emphasis on the overlap of the various fields of science. Gerbasch emphasized that as science becomes more advanced, the more intermixed the various disciplines of science become with each other. Thus while Gerbasch majored in chemical engineering, he is also well versed in other fields of science such as genetics and molecular biology. Seeing how various fields of science intermingle with each other is something I find very interesting and hope to find in a career.

Cutting-edge research is currently being conducted at the Gerbasch lab. The lab is using various genetic-engineering methods to research ways to improve treatment for patients of an abundance of diseases and disabilities. I really enjoyed hearing how open-minded the Gerbasch lab is to experimenting with various methods.

Overall, I really enjoyed the faculty seminars. Being an undergraduate who has little idea what type of career I want to pursue, it was interesting seeing the journey these various faculty members took to end up in their careers. I also enjoyed hearing all of the life lessons and perspectives on science the various faculty members shared and I learned a lot from the insights they had to share.

Piercing Alarms & Morning Meetings

7:50am… 8:00… 8:10… 8:20… 8:30… 8:35… These are all the alarms my roommate had to suffer through on a daily basis as I tried to convince myself to wake up for our morning faculty seminars. Although dragging myself out of bed and then rushing to get ready because I was running late (again) is not my idea of fun, the speakers made it worth it. Apart from learning about interesting research, it was reassuring to hear about the zigzagging career paths that many of the speakers had taken.

Two talks stood out in particular. The first was Provost Sally Kornbluth’s talk on research misconduct. I’ve grown up loving shows like CSI, Law & Order and White Collar, and the case study of Anil Potti, a former Duke medical researcher, sure felt like the academia version! Her talk also struck a chord because I’ve been thinking a lot about the failings of biomedical research after reading the book Rigor Mortis by Richard Harris (shout-out to Dr. Brian Hare for the recommendation). I’m not saying that basic science research is unnecessary—it has resulted in many life-changing (literally) discoveries. However, it isn’t perfect. The lack of severe repercussions for Anil Potti is a case in point (he is still a practicing doctor and will be allowed to conduct research again after 2020).

The second talk that caught my attention was that of Dean Stephen Nowicki who spoke about learning and mate selection in song birds. Having taken his class last semester, I knew some of the information but listened with newfound appreciation for the evolutionary perspective. It was especially fascinating to hear about his research on geographically comparing song repertoires between groups of male swamp sparrows. Song types varied between groups with groups farther away from each other being more distinct. Females tended to respond preferentially to males singing songs typical of their group with their responsiveness diminishing as songs from groups further away were played. This indicates that females’ notions of a ‘good song’ are learned through experience and exposure. Who would have guessed that songbirds are such an ideal species to study language and learning!

Moist Toilet Paper

Dr. Charles Gersbach wakes up each morning motivated and excited by the thought that he can discover something new and fresh with his passion and hard work.

He didn’t feel he could find such motivation through moist toilet paper, an idea proposed by Kimberly Clark, or through transfecting cells everyday to protect toddlers from RSV infections.

Of course, both moist toilet paper and cell transfections are important in their own ways, but Dr. Gersbach felt like he was simply “one little cog in a bigger machine.”

However, once he tasted the side of academia by experiencing a bone growth product, he found a new love and freedom for lab. His idea of what “engineering” meant shifted, especially for cutting edge research.

Now, Dr. Gersbach works with CRISPR and Genome Editing to decipher the dilemma of muscular dystrophy and attempts to differentiate between gene editing and gene therapy to capitalize, understand, and edit the dystrophin protein holding together muscle cells. As an aspiring engineer fascinated with CRISPR and genome editing myself, I was extremely interested in how he tackled the gene editing portion and how he found the balance between engineering and biology.

Dr. Gersbach fought a dilemma that I find myself facing; industry v.s. academia. His insight into how he felt with his experiences in industry versus the freedom he finds through academia proves extremely helpful as I attempt to figure out what I want from the future. Thank you Dr. Gersbach for a wonderful faculty talk!

Science and More Science

I thoroughly enjoyed these seminars. Not only did I learn more about other research that I might not have thought of exposing myself to, but I also got to know how these researchers became…researchers. To be completely honest, it’s nice hearing from the researchers who didn’t see themselves as researchers from their early undergraduate years.

Out of all of the seminars, it was really difficult to choose only one to talk about, so I’ve decided to pick two! I promise to keep it short-ish.

First up, Dr. Anne West, since her seminar is still fresh in this forgetful brain of mine. One question that she brought up was why she wanted to be a basic scientist. There are so many people who really look for research that will show immediate/direct benefits in real world applications. However, like what Dr. West explained through her captivating storytelling, basic science is so essential. Without it, we wouldn’t be able to progress as much as we have thus far. The fact that CRISPR was essentially discovered 30 years before it became popular in the science world is just mind blowing. Research that might seem pointless at first, might have a very important role in the future. On top of that, her research is really interesting. I wasn’t aware that neurons could change so much so quickly.

She really reminded me of why I like science so much; why I want to become a researcher. My love for epigenetics just keeps increasing!

Next up: Dr. Gersbach. His lab really interested me because he said that even though he’s known to be fiddling around in biomedical engineering, his colleagues don’t really consider him and his lab to be “biomedical engineering”. Instead, his lab and interests lie in many different fields, which is completely relatable. Who is only interested in one very specific topic their whole life? (okay, probably quite a few people, but I rest my case) He doesn’t want to limit himself. Out of all of this research this summer, I’ve kind of learned that each lab is a bit isolating. You could become lost within the narrow scope that your lab focuses on and not know what’s going on in the rest of the researching world. The fact that Dr. Gersbach is so willing to explore other fields and defy, I guess, labels is pretty cool. His research itself is very interesting because, even though I have absolutely no knowledge about engineering, I become completely intrigued whenever gene editing or genetic engineering is brought up (I’m a genome/epigenome freak, what can I say). It’s just so interesting to me, that I’d be willing to read articles upon articles on it (maybe).

Can you sense how interested and excited I am with all of this science? Can you? Because I think I can.

I guess all this proves that…science is cool.

The Origins of Dr. Amir Rezvani

Credits: Duke DIBS

Dr. Amir Rezvani is a professor of Psychiatry and Behavioral Sciences and Associate Director of Addiction Division at Duke University in addition to being one of the PI in the lab that I am working in this summer. One of the first things I noticed about him when I met him was his amazing sense of humor, which makes working in his lab joyful. He is definitely not the stereotypical scientist that we all imagine in our heads; one that never smiles or jokes, and is about science 24/7. In fact, he is quite the opposite. This week I decided to give him a short interview so I can learn more about him and his journey in the scientific world.

Dr. Rezvani was born in Persia (Iran) where he did his undergraduate at the prestigious University of Tehran which is the best and oldest university in the Middle East. He received his undergraduate degree in biology then got his masters in teaching biology. Although he was accepted in medical school and even put down a deposit for his tuition so that his spot could be saved, at the end he decided to go into biology instead of going to medical school. When I asked him why he chose to give up medicine to be a scientist, he replied that his high school science teacher was the main force in convincing him to pursue biology and the life sciences. That teacher had so much passion for the life sciences that became contagious that Dr. Rezvani caught it. After high school, he decided that he wanted a more science-based career so he gave up medicine to pursue something he loved more.

For graduate school, he came to the United States and landed in Missouri where he received another Master degree in Physiology. As if he didn’t have enough degrees, Amir Rezvani became Dr. Amir Rezvani, receiving a Ph.D. in Neurophysiology from the University of Illinois at Urbana- Champaign. He said he was drawn to neurophysiology because there was so much unknown in the field and there were great opportunities for discoveries. He was also interested in human behavior and neurophysiology encompassed that. At that time, his research looked at the effects of beta endorphins, a newly discovered endogenous peptide, on temperature regulation in rabbits. He then went to University of North Carolina at Chapel Hill for his postdoc (which explains his loyalty to UNC). After finishing his postdoc, he was recruited as a faculty in the department of Psychiatry at UNC where he became interested in addiction to alcohol by using alcohol drinking rats and monkey. In 1999, he finally came to Duke University and began working with Dr. Edward Levin. However, his unfaltering loyalty to UNC did not change (even though he is working at Duke which is kind of like enemy territory for him).

His advice for budding scientist is to be curious as much as you can about everything and read as much as you can. Read literature and then talk to other scientists, expose yourself to other scientists by going to talks and seminars and meetings and conferences. Doing all of this will help you find what you really love and what excites you. At the end of the day, you have to love it. Because you don’t want to wake up in the morning and hate what you’re doing. Life is too short for that. And last but not least, you need to be passionate about helping other people especially for medicine but also for science. Because every addition to the human knowledge, no matter how small, can eventually help someone somewhere in the world.

As you can see, Dr. Rezvani has lived a very dynamic and science-filled life, always ready to learn more. One can learn a lot from his life and experiences. I think the thing that I learned from listening to him is to always be prepared to learn (because he wouldn’t have collected so many degrees if he didn’t like learning) and to not be afraid to go against the tide and do things that you really enjoy. This lesson not only applies to budding physician/scientists like me but also everyone in the world.

 

Abstract

Limitations to dopamine D2 ligands for antipsychotic efficacy.

The D2 receptor has often been examined as the target for antipsychotic drugs due to its distribution in critical areas of the brain involved in movement and reward. Beta-arrestin biased drugs such as UNC9994 function as antagonists through G-protein signaling and partial agonists through beta-arrestin signaling, which has been shown to decrease psychotic properties while minimizing unwanted side effects. Of the five dopamine receptors, D2 closely mirrors D3 and D4. Therefore, it has been proposed that these novel therapeutics may be having an effect on the dopamine D3 and D4 receptors. Using BRET assays with HEK293 cell lines, aripiprazole and its congener UNC9994 have been tested on the dopamine D2-D4 receptors, and their effects were recorded as dose-response curves. By comparing the effect of the drugs to the effect of the natural ligand dopamine, it has been discovered that these agents do have an effect at the D3 and D4 receptors. Due to the role of non-D2 dopamine receptors in contributing to many of the symptoms of schizophrenia, novel therapeutic agents remain to be developed that could have the receptor specificity needed to attenuate psychotic phenotypes while minimizing unwanted side effects.

Chalk Talk Reflections

In the Caron lab, my project has largely been testing new schizophrenia drugs on the dopamine receptors. Because my interests in the sciences have largely revolved around pharmacology and cell biology, I have usually approached the concept of neuropsychiatric disorders as a dysregulation of neurotransmitter systems that can be fixed by the administration of a molecular substance (i.e. drug). This would involve knowledge of the receptor and the subsequent effects it has on the cell. This approach to these disorders focuses on abating symptoms once they are present in a patient (or forced in an animal model), and does not truly examine the causes of such disorders (but merely the effects). Thus, I was quite fascinated to hear about some of my colleague’s labs which focus on proposed causes for certain disorders, like the role of gut microbiota in contributing to depression.

One chalk talk that really grabbed my attention was the one given by Annika Sharma. In the talk, she stressed that experiments transferring fecal matter from a depressed mouse (mice eat poop) into a healthy mouse was able to induce depression in the healthy mouse, suggesting a role for the gut microbiota in facilitating connections with the brain (i.e. the gut-brain access). It is also known that Major Depressive Disorder (MDD) patients have altered microbial compositions and many metabolites which play a role in depression are byproducts of gut microbiota. I was also rather shocked by the way in which her lab generates what it calls the social defeat paradigm. Essentially, to create a depressed mouse, it is left in the company of older, more aggressive mice that beat it up. The lab then extracts fecal matter from the depressed mouse and is able to run any series of tests that they want to determine, for instance, the presence or absence of certain metabolites. Overall, I was just interested in learning the many different ways in which researchers have approached certain disorders.

A Day in the Life

For me, each day of the week in the Caron lab is dedicated to a different procedure with the overall goal of generating data for my project. Thanks to my dedicated mentor who goes to lab on Sunday, I am able to run three rounds of BRET in a week.

On Mondays, I transfect the cells that my mentor split the day before. I also split cells for transfections on Tuesdays. On Tuesdays, I split the transfected cells to a 96 well plate for BRET and transfect the cells split on Monday. On Wednesday, I am able to finally use the BRET machine and see if my transfections and plating reveal any interesting results. Like is expected for good science, I try to achieve many rounds of similar results with BRET assay to assure that the data is not due to error on my part. Thus, I run BRET on Thursdays and Fridays as well.

While the BRET assay is my main objective in lab, it is not the only thing I do. Each time I transfect, I have to use some DNA from the stocks we keep in the fridge. After many rounds of BRET, the DNA starts to run low. Therefore, I occasionally engage in cloning projects in order to make more DNA. Sometimes, I am lucky that other people in the lab have glycerol stocks of the DNA I need. If so, I am able to utilize a Qiagen MidiPrep in order to extract more DNA. However, if no glycerol stocks are available, I have to transform the DNA in bacteria and let the bacteria grow up copies for me.

In addition to all of these small mini cloning projects, I did partake in a fairly lengthy cloning project that lasted an entire week. I attached a fluorescent probe to the D3 receptor.

So, this is how I have been keeping busy in lab. Sometimes, if I finish everything I have to in a day (or if there ends up being too few cells to split), my mentor will keep me busy with random projects that usually involve new techniques. One thing is for sure, there is never a boring day in the Caron lab.

Investigating the Role of PTPRZ1 in Astrocytes

Astrocytes are a non-neuronal cell population in the brain which perform many important functions, including regulating synapse formation and function and helping to form the blood brain barrier. Despite the importance of these cells in vivo, little is known about how they carry out these critical functions. Protein Tyrosine Phosphatase Receptor Z1 (PTPRZ1) is a transmembrane protein which is heavily expressed in astrocytes and oligodendrocytes, another non-neuronal cell in the brain. While some function has been found for PTPRZ1 in controlling oligodendrocyte maturation, little is known about the function of the protein in astrocytes. The present study investigates the role of this protein by determining its location of action, its expression across development, and finally what it is doing in astrocytes. To determine the location in which PTPRZ1 is acting, immunohistochemistry (IHC) was used on mouse brain sections. These tests showed expression of PTPRZ1 along the branches of astrocytes, with a co-localization between the PTPRZ1 and our astrocyte marker GFP. We also found the protein to be present on western blot in the brains of mature animals. We plan to continue this work by investigating PTPRZ1 levels over different developmental time-points using western blot and quantitative PCR analysis.

Abstract Draft (199 words)

Identifying the endoreplication pathway in Cryptococcus neoformans

Aaliyah Davy                                                                                                                     Mentors: Ci Fu, PhD., Joseph Heitman, MD., PhD.                                             Department of Molecular Genetics and Microbiology

Cryptococcus neoformans is an opportunistic fungal pathogen that affects the immunocompromised and rarely, the immunocompetent. The fungus has two different sexual cycles- that is, bisexual and unisexual. Central to bisexual reproduction is cell and nuclear fusions that are indicative of ploidy duplication and the yeast-hyphal morphology transition. In this study, we investigated the currently unidentified endoreplication cycles that these cells go through to attain ploidy replication in the unisexual cycle. We hypothesized that one of six cell cycle genes we have chosen, that have differential expression throughout unisexual reproduction, will have some impact on the pathway. To test this, we generated gene deletion constructs with dominant selectable marker neomycin (G418), and conducted biolistic transformation on the unisexual strain XL280α. Transformants were streaked on additional G418 plates and verified by PCR. We tested whether deletion of these genes impact unisexual reproduction. This endoreplication pathway has also been linked to the formation of titan cells (greatly enlarged versions of the pathogen) in host infection, so we tested the significance of these genes in titan cell formation as well.

Abstract Draft

Randomly self-assembling copolymers have repeatedly demonstrated great promise toward eliciting therapeutic immune responses, and specifically for autoimmune diseases. However, their mechanisms of action are not yet fully understood. Many factors such as pH and temperature can affect the nature of the self-assembly of copolymers thus influencing immunogenicity. We tested the hypothesis that factors such as pH and temperature can be manipulated to optimize the self-assembly of copolymers thus eliciting a more desirable immune response through shifting the nature of the T-cell response. This was implemented by analyzing the effect of pH, temperature, and sonication on the stability of the copolymers dissolved in solution. According to our results, increasing heat and pH were the most effective methods to optimize the formation of fibers. We next plan to use these copolymer solutions to vaccinate mice and use methods like ELISA to analyze the nature of their immune responses. This will help us gain a better understanding of the ideal steps to be taken to increase the solubility of these copolymers while simultaneously optimizing their immunomodulatory actions. Through exploring different methods to increase the solubility of copolymers in solution, we can work to better understand how to optimize the immunogenicity of copolymers in vaccinations.