by Chris Hawk ’16
During the summer of 2015, I have been studying strategies to detect fungal pathogens of Humulus lupulus, commonly referred to as hops. The hops crops of Virginia have been threatened in recent years by a number of microbial pests, making studies of the ways in which hops and microbes interact both scientifically and commercially interesting. In order to do so, I have been growing live tissue in our greenhouse, by means of steam propagation and the transplanting of rhizomes from live tissue. Currently, I have a few varieties and species of Hops in the greenhouse, including Cascade, Mt. Hood, Willamette, an unknown variety found locally, and Humulus japonicas—an invasive hop.
Setting up the hops lines in the greenhouse at the start of the summer
Using the greenhouse to grow these plants has, for the most part, kept the fungal pathogens Pseudoperonospora humuli (downy mildew) and Podosphaera macularis (powdery mildew) from infecting the plants. However, I have been purposefully infecting the hops with the two fungal pathogens to determine how quickly the plants become infected before they show phenotypic signs of infection. Understanding how these fungal pathogens best develop and spread on hops will allow me to better understand how they can be effectively controlled.
Working with mature hops at the end of the summer
This work will be a central part of Hampden-Sydney’s introductory biology lab course in the Fall of 2015. Here, several students will build on the results I find to try and better understand how hops can be most effectively grown and managed in Virginia.
by Mason Luck ’16
Ecosystems are complex. Between thousands of years of symbiotic relationships a given system becomes stable. That is not to say that each facet is perfect, but it works. When one piece of the system is thrown off the whole system will inevitably feel the effects and could collapse as a result. Invasive species throw off the natural balance. Centaurea stoebe, otherwise known as the spotted knapweed, is an invasive species of flora close to home. It affects natural systems by outcompeting natives, causing all sorts of problems. Fields of wild grass can be taken over completely by Centaurea in effect disrupting livestock feeding grounds. In the more natural sense it may completely replace the native species, taking out the first level of a stable trophic chain. If you knock out the base of a building it is bound to collapse, much like the base of the food chain.
The goal of my research is to discover particulars about how Centaurea survives-especially as it pertains to substrates and watering schemes. Thus far I am working with roughly 715 Centaurea seedlings. The substrates I am using are sand and soil. I plan to analyze how fast/how well plants grow in each substrate, giving me a glimpse into their competitive abilities in a nutrient poor and nutrient rich environment. If they can grow in sand they may have an advantage in utilizing a substrate that is hard to be used by others. If they grow in soil, they still show that they can compete in an environment fit for other flora. The plants will receive three different watering treatments: low, medium, and high. Depending on survival and growth we can see if Centaurea has the competitive advantage of being able to withstand harsh conditions, as well as normal and high watering conditions. Once the plants are reproductively active the amount of seeds they produce will show us how well they are able to adjust to each treatment. If they produce many seeds they did very well, as they were able to devote energy to making seeds instead of growing more roots or leaves to counterbalance our treatements.
Mason with a sample of Centaurea stoebe collected locally from the High Bridge Trail.
In May, Dr. Goodman assisted a group of ecologists working on a unique island system in Great Abaco, Bahamas. For 10 days, she and Amber Wright
of University of Hawaii caught, marked, and measured Anolis sagrei
lizards derived from populations introduced to 16 tiny islands two years ago. These islands will be compared to 16 additional islands that did not receive lizard introductions to determine the impact of “top down” predator effects on these ecosystems. Plant growth and invertebrate populations are being monitored by ecologists Jonah Piovia-Scott
, Louie Yang
, and David Spiller
. This island system is also being used to determine the impact of “bottom up” effects of resource subsidies, in the form of hundreds of pounds of seaweed delivered to 16 of the 32 islands.
Every June, representative from institutions participating in the Howard Hughes Medical Institute (HHMI) Science Education Alliance-Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) program gather for a student symposium at HHMI’s Janelia Farm Research Campus in Ashburn, VA. Hampden-Sydney has participated in SEA-PHAGES since 2011, with students isolating bacteriophages from the environment and performing molecular and bioinformatic characterization as part of a national project on bacteriophage evolution based out of the University of Pittsburgh. This year’s H-SC student representatives were Joshua Dimmick ’15 and Taylor Meinhardt ’16.
Taylor Meinhardt ’16, Joshua Dimmick ’15, and Professor Mike Wolyniak with the H-SC research poster
Dimmick and Reinhardt were both in Professor Mike Wolyniak’s Molecular and Cellular Biology class in the Fall 2014 semester in which the class discovered several Bacillus-based bacteriophages, including one isolated by Stephen Woodall ’15 called Archie14 that was the subject of further investigation for the symposium.
Dimmick and Meinhardt present their poster
The symposium attracted students and faculty from ~80 institutions nationwide that participate in the SEA-PHAGES initiative and was keynoted by Eric Betzig, co-recipient of the Nobel Prize in Chemistry in 2014 for his work in microscopy.
Associate Professor of Biology Dr. Kristian M. Hargadon ’01 recently published a major research article on melanoma-altered function of dendritic cells in the journal Immunology and Cell Biology. Published by Nature Publishing Group, one of the leading publishers of scientific and medical journals, Immunology and Cell Biology places particular emphasis on the cellular biology of the immune system. Dr. Hargadon’s article, entitled “Melanoma-derived factors alter the maturation and activation of differentiated tissue-resident dendritic cells,” includes 5 Hampden-Sydney College student co-authors who have worked on various aspects of this project in his lab over the past 3 years. These student authors are Drake Bishop, Jay Brandt, Charlie Hand, Yonathan Ararso, and Osric Forrest. Osric Forrest is currently a Ph.D. candidate in the Immunology Graduate Program at Emory University, Drake Bishop and Jay Brandt are both pursuing an M.D. at Eastern Virginia Medical School, and Yonathan Ararso is in the process of applying to M.D./Ph.D. programs. The research reported in their article (http://www.nature.com/icb/journal/vaop/ncurrent/abs/icb201558a.html
) describes how aggressive melanomas compromise the function of dendritic cells in a way that may ultimately promote tumor escape from host immune responses. Dr. Hargadon’s research program is currently funded by a grant from the Commonwealth Health Research Board.
This summer two H-SC students, Jefferson Thompson ’16 and Travis Goodloe 16′, are conducting melanoma research in the laboratory of Associate Professor of Biology Dr. Kristian M. Hargadon ’01. In addition to support from the College’s Honors Council and a Commonwealth Health Research Board grant to Dr. Hargadon, both students have also received external funding for their work. Travis Goodloe received a Sigma Xi Grant-in-Aid of Research for a project entitled “Validation of a Quantitative Polymerase Chain Reaction (qPCR)-based Method for Detecting Lymph Node Metastasis by Melanoma Cells.” He is developing an assay to measure the spread of regional melanomas into tumor-draining lymph nodes, and this work will serve as a foundation for future studies that aim to investigate how lymph node involvement by melanoma cells impacts the induction of immune responses to this tumor. Jefferson Thompson received a Virginia Foundation for Independent Colleges Undergraduate Science Research Fellowship for a project entitled “Generation of a Foxc2 Gene Knockout Murine Melanoma Cell Line via CRISPR-Cas9 Genome Editing Technology.” CRISPR-Cas9 gene editing has revolutionized the field of genetic engineering since its discovery in 2013, and Jefferson is the first student to employ this technology at Hampden-Sydney College. He will be editing the nucleotide sequence of the Foxc2 gene in a mouse melanoma cell line so that the protein encoded by this gene is no longer produced. This “knockout” cell line will be used in future studies to investigate the role of the FOXC2 transcription factor in regulating melanoma metastasis, and those studies will utilize the metastasis assay being developed by Travis. If the FOXC2 protein is shown to promote melanoma spread to lymph nodes, it may serve as both a clinical marker for the progression of this cancer as well as a novel therapeutic target for cancer treatments designed to eradicate metastatic melanoma. Both Jefferson and Travis plan to attend medical school upon their graduation from H-SC!
Jefferson Thompson ’16 (right) and Travis Goodloe ’16 (left) hard at work in the lab!
Jefferson has become a pro at gel electrophoresis!
Travis dissecting a melanoma tumor-bearing mouse!
Five Hampden-Sydney College sophomore students were recently accepted into medical schools through Early Assurance Programs that the College has established. James Lau ’17 was accepted at Eastern Virginia Medical School, Brant Boucher ’17 and Will Echols ’17 were both accepted at Virginia Commonwealth University’s School of Medicine, and Benjamin Lam ’17 and Robert Kerby ’17 were both accepted at the George Washington University School of Medicine and Health Sciences. Through articulation agreements established between Hampden-Sydney College and each medical institution, competitive students apply during their sophomore year for admittance into medical school. Once accepted, successful students complete their 4 years of undergraduate work at H-SC and have guaranteed admission to medical school following their graduation. Congratulations to this year’s successful applicants and future doctors!
The H-SC Biology Class of 2015 has been especially productive when it comes to original research. Below are a list of the topics covered by this class in their Departmental Honors and Senior Fellowship projects that gives a flavor for the wide array of research opportunities for present and future students in the Biology Department.
“Effects of herbicides and ranavirus, an emerging infectious disease, on juvenile Red-Eared Slider turtles (Trachemys scripta elegans)”–Davis Carter ’15
“Analysis of substrates on growth performance of Centaurea stoebe ssp. micranthos (Asteraceae) using field and lab studies”–Erik Kellogg ’15
“Greenhouse and Field Studies of the Invasive Aster Centaurea stoebe (Asteraceae) and a Native Competitor Lespedeza capitata (Fabaceae)”–Sean Kellogg ’15
“RNAi analysis of Lag-1 Isoform D in Caenorhabditis elegans, a homolog of Suppressor of Hairless (Su(H))”–Daniel Osarfo-Akoto ’15
“Genetic Engineering of the Murine Melanoma D5.1G4 to Express a Model Antigen for Evaluation of Anti-tumor CD8+ T Cell Responses”–Stephen Woodall ’15
“Synthesis and Application of Small Cationic Peptides as Potential Antibiotics”–Jay Brandt ’15 and Christopher Ferrante ’15 (in cojunction with the Department of Chemistry)
“The Generation of Trichromatic Vision via Adeno-Associated Virus (AAV) Vector Expressing Red-Shifted Channelrhodopsin (ReaChR)”–Aaron Gilani ’15 (in conjunction with the Department of Psychology)
“Evolution of the Eye and its Extreme Capabilities”–Jeffrey Gray ’15 (in conjunction with the Department of Physics and Astronomy)
Each spring, the College of William and Mary invites Virginia participants in the Howard Hughes Medical Institute Science Education Alliance-Phage Hunters Advancing Genomics and Evolutionary Science (HHMI SEA-PHAGES) project to their campus for a meeting for students to share their research work on the isolation and characterization of novel bacteriophages from the environment. This year, Hampden-Sydney students Josh Dimmick ’15, Grayland Godfrey ’15, and Taylor Meinhardt ’16 accompanied Professor Mike Wolyniak to Williamsburg and gave the College’s presentation on Archie14, a Bacillus thuringiensis
bacteriophage discovered by Stephen Woodall ’15 on the H-SC campus.
Taylor Meinhardt ’16, Josh Dimmick ’15, and Grayland Godfrey ’15 give their presentation to the William and Mary audience
The SEA-PHAGES program has expanded to include over 70 institutions nationwide and more than 4,800 undergraduates conducting original research on bacteriophage genomics and evolution based out of the University of Pittsburgh. Participating institutions include small liberal arts colleges like Hampden-Sydney, Smith, and Gettysburg and large research universities like Brown, Ohio State, and Washington State working towards a common research goal of a better understanding of bacteriophage diversity. In Virginia, the SEA-PHAGES project is done at Hampden-Sydney, William and Mary, Mary Washington, James Madison, Virginia Commonwealth, and Old Dominion.
Dimmick, Godfrey, Thomas Jefferson, and Meinhardt on the central campus of William and Mary. Given as a gift by the University of Virginia, Jefferson’s statue at William and Mary, his alma mater, faces Charlottesville and the university he would eventually found in the latter years of his life.