Author Archives: Lillian Padgitt-Cobb

Stream ecosystems and a changing climate

Examining the effect of climate change on stream ecosystems

Oak Creek near McDonald Dunn research lab. The salamander and trout in the experiments were collected along this stretch of creek.

As a first year Master’s student in the lab of Ivan Arismendi, Francisco Pickens studies how the changing, warming climate impacts animals inhabiting stream ecosystems. A major component of stream ecosystem health is rainfall. In examining and predicting the effects of climate change on rainfall, it is important to consider not only the amount of rainfall, but also the timing of rainfall. Although a stream may receive a consistent amount of rain, the duration of the rainy season is projected to shrink, leading to higher flows earlier in the year and a shift in the timing of the lowest water depth. Currently, low flow and peak summer temperature are separated by time. With the shortening and early arrival of the rainy season, it is more likely that low flow and peak summer temperature will coincide.

A curious trout in one of the experimental tanks.

Francisco is trying to determine how the convergence of these two events will impact the animals inhabiting streams. This is an important question because the animals found in streams are ectothermic, meaning that they rely on their surrounding environment to regulate their body temperature. Synchronization of the peak summer temperature with the lowest level of water flow could raise the temperature of the water, profoundly impacting the physiology of the animals living in these streams.

 

 

How to study animals in stream ecosystems?

Salamander in its terrestrial stage.

Using a simulated stream environment in a controlled lab setting, Francisco studies how temperature and low water depth impact the physiology and behavior of two abundant stream species – cutthroat trout and the pacific giant salamander. Francisco controls the water temperature and depth, with depth serving as a proxy for stream water level.

Blood glucose level serves as the experimental readout for assessing physiological stress because elevated blood glucose is an indicator of stress. Francisco also studies the animals’ behavior in response to changing conditions. Increased speed, distance traveled, and aggressiveness are all indicators of stress. Francisco analyzes their behavior by tracking their movement through video. Manual frame-by-frame video analysis is time consuming for a single researcher, but lends itself well to automation by computer. Francisco is in the process of implementing a computer vision-based tool to track the animals’ movement automatically.

The crew that assisted in helping collect the animals: From left to right: Chris Flora (undergraduate), Lauren Zatkos (Master’s student), Ivan Arismendi (PI).

Why OSU?

Originally from a small town in Washington state, Francisco grew up in a logging community near the woods. He knew he wanted to pursue a career involving wild animals and fishing, with the opportunity to work outside. Francisco came to OSU’s Department of Fisheries and Wildlife for his undergraduate studies. As an undergrad, Francisco had the opportunity to explore research through the NSF REU program while working on a project related to algae in the lab of Brooke Penaluna. After he finishes his Master’s degree at OSU, Francisco would like to continue working as a data scientist in a federal or state agency.

Tune in on Sunday, June 24th at 7pm PST on KBVR Corvallis 88.7 FM, or listen live at kbvr.com/listen.  Also, check us out on Apple Podcasts!

Ocean sediment cores provide a glimpse into deep time

Theresa on a recent cruise on the Oceanus.
Photo credit: Natasha Christman.

First year CEOAS PhD student Theresa Fritz-Endres investigates how the productivity of the ocean in the equatorial Pacific has changed in the last 20,000 years since the time of the last glacial maximum. This was the last time large ice sheets blanketed much of North America, northern Europe, and Asia. She investigates this change by examining the elemental composition of foraminifera (or ‘forams’ for short) shells obtained from sediment cores extracted from the ocean floor. Forams are single-celled protists with shells, and they serve as a proxy for ocean productivity, or organic matter, because they incorporate the elements that are present in the ocean water into their shells. Foram shell composition provides information about what the composition of the ocean was like at the point in time when the foram was alive. This is an important area of study for learning about the climate of the past, but also for understanding how the changing climate of today might transform ocean productivity. Because live forams can be found in ocean water today, it is possible to assess how the chemistry of seawater is currently being incorporated into their shells. This provides a useful comparison for how ocean chemistry has changed over time. Theresa is trying to answer the question, “was ocean productivity different than it is now?”

Examples of forams. For more pictures and information, visit the blog of Theresa’s PI, Dr. Jennifer Fehrenbacher: http://jenniferfehrenbacher.weebly.com/blog

Why study foram shells?

Foram shells are particularly useful for scientists because they preserve well and are found ubiquitously in ocean sediment, offering a consistent glimpse into the dynamic state of ocean chemistry. While living, forams float in or near the surface of the sea, and after they die, they sink to the bottom of the sea floor. The accumulating foram shells serve as an archive of how ocean conditions have changed, like how tree rings reflect the environmental conditions of the past.

Obtaining and analyzing sediment cores

Obtaining these records requires drilling cores (up to 1000 m!) into deep sea sediments, work that is carried out by an international consortium of scientists aboard large ocean research vessels. These cores span a time frame of 800 million years, which is the oldest continuous record of ocean chemistry. Each slice of the core represents a snapshot of time, with each centimeter spanning 1,000 years of sediment accumulation. Theresa is using cores that reach a depth of a few meters below the surface of the ocean floor. These cores were drilled in the 1980s by a now-retired OSU ship and are housed at OSU.

Theresa on a recent cruise on the Oceanus, deploying a net to collect live forams. Photo credit: Natasha Christman.

The process of core analysis involves sampling a slice of the core, then washing the sediment (kind of like a pour over coffee) and looking at the remainder of larger-sized sediment under a powerful microscope to select foram species. The selected shells undergo elemental analysis using mass spectrometry. Vastly diverse shell shapes and patterns result in different elements and chemistries being incorporated into the shells. Coupled to the mass spectrometer is a laser that ablates through the foram shell, providing a more detailed view of the layers within the shell. This provides a snapshot of ocean conditions for the 4 weeks-or-so that the foram was alive. It also indicates how the foram responded to light changes from day to night.

Theresa is early in her PhD program, and in the next few years plans to do field work on the Oregon coast and on Catalina island off the coast of California. She also plans to undertake culturing experiments to further study the composition of the tiny foram specimens.

Why grad school at OSU?

Theresa completed her undergraduate degree at Queen’s University in Ontario, followed by completion of a Master’s degree at San Francisco State University. She was interested in pursuing paleo and climate studies after transformative classes in her undergrad. In between her undergraduate and Master’s studies she spent a year working at Mt. Evans in Colorado as part of the National Park Service and Student Conservation Association.

Theresa had already met her advisor, Dr. Jennifer Fehrenbacher, while completing her Master’s degree at SF State. Theresa knew she was interested in attending OSU for grad school for several reasons: to work with her advisor, and to have access to the core repository, research ships, and technical equipment available at OSU.

To hear more about Theresa’s research and her experience as a PhD student at OSU, tune in on Sunday, June 10th at 7pm on KBVR Corvallis 88.7 FM, or listen live at kbvr.com/listen.  Also, check us out on Apple Podcasts!

When Fungus is Puzzling: A Glimpse into Natural Products Research

Ninety years ago, a fungal natural product was discovered that rocked the world of medicine: penicillin. Penicillin is still used today, but in the past ninety years, drug and chemical resistance have become a hot topic of concern not only in medicine, but also in agriculture. We are in desperate need of new chemical motifs for use in a wide range of biological applications. One way to find these new compounds is through natural products chemistry. Over 50% of drugs approved in the last ~30 years have been impacted by natural products research, being directly sourced from natural products or inspired by them.

Picture a flask full of microbe juice containing a complex mixture of hundreds or thousands of chemical compounds. Most of these chemicals are not useful to humans – in fact, useful compounds are exceedingly rare. Discovering new natural products, identifying their function, and isolating them from a complex mixture of other chemicals is like solving a puzzle. Donovon Adpressa, a 5th year PhD candidate in Chemistry working in the Sandra Loesgen lab, fortunately loves to solve puzzles.

Nuclear Magnetic Resonance (NMR): an instrument used to elucidate the structure of compounds.

Donovon’s thesis research involves isolating novel compounds from fungi. Novel compounds are identified using a combination of separation and analytical chemistry techniques. Experimentally, fungi can be manipulated into producing compounds they wouldn’t normally produce by altering what they’re fed. Fungi exposed to different treatments are split into groups and compared, to assess what kind of differences are occurring. By knocking out certain genes and analyzing their expression, it’s possible to determine how the compound was made. Once a new structure has been identified and isolated, Donovon moves on to another puzzle: does the structure have bioactivity, and in what setting would it be useful?

Donovon’s interest in chemistry sparked in community college. While planning to study Anthropology, he took a required chemistry course. Not only did he ace it, but he loved the material. The class featured a one-week lecture on organic chemistry and he thought, ‘I’m going to be an organic chemist.’ However, there were no research opportunities at the community college level, and he knew he would need research experience to continue in chemistry.

At Eastern Washington University, Donovon delved into undergraduate research, and got to work on a few different projects combining elements of medicinal and materials chemistry. While still an undergrad, Donovon had the opportunity to present his research at OSU, which provided an opportunity to meet faculty and see Corvallis. It all felt right and fell into place here at OSU.

As a lover of nature and hiking in the pacific northwest, Donovon has always had a soft spot for mycology. It was serendipitous that he ended up in a natural products lab doing exactly what interested him. Donovon’s next step is to work in the pharmaceutical industry, where he will get to solve puzzles for a living!

Tune in at 7pm on Sunday, March 18th to hear more about Donovon’s research and journey through graduate school. Not a local listener? Stream the show live.

Exploring a protein’s turf with TIRF

Investigating Otoferlin

Otoferlin is a protein required for hearing. Mutations in its gene sequence have been linked to hereditary deafness, affecting 360 million people globally, including 32 million children. Recently graduated PhD candidate Nicole Hams has spent the last few years working to characterize the activity of Otoferlin using TIRF microscopy. There are approximately 20,000 protein-coding genes in humans, and many of these proteins are integral to processes occurring in cells at all times. Proteins are encoded by genes, which are comprised of DNA; when mutations in the gene sequence occur, diseases can arise. Mutations in DNA that give rise to disease are the focus of critical biomedical research. “If DNA is the frame of the car, proteins are the engine,” explains Nicole. Studying proteins can provide insight into how diseases begin and progress, with the strategic design of therapies to treat disease founded on our understanding of protein structure and function.

Studying proteins

Proteins are difficult to study because they’re so small: at an average size of ~2 nanometers (0.000000002 meters!), specific tools are required for visualization. Enter TIRF. Total Internal Reflection Fluorescence is a form of microscopy enabling scientists like Nicole to observe proteins tagged with a fluorescent marker. One reason TIRF is so useful is that it permits visualization of samples at the single molecule level. Fluorescently-tagged proteins light up as bright dots against a dark background, indicating that you have your protein.

Another reason why proteins are hard to study is that in many cases, parts of the protein are not soluble in water (especially if part of the protein is embedded in the fatty cell membrane). Trying to purify protein out of a membrane is extremely challenging. Often, it’s more feasible for scientists to study smaller, soluble fragments of the larger protein. Targeted studies using truncated, soluble portions of protein offer valuable information about protein function, but they don’t tell the whole story. “Working with a portion of the protein gives great insight into binding or interaction partners, but some information about the function of the whole protein is lost when you study fragments.” By studying the whole protein, Nicole explains, “we can offer insight into mechanisms that lead to deafness as a result of mutations.”

Challenges and rewards of research

Nicole cites being the first person in her lab to pursue single molecule studies as a meaningful achievement in her graduate career. She became immersed in tinkering with the new TIRF instrument, learning from the ground up how to develop new experiments. Working with cells containing Otoferlin, in a process known as tissue culture, required Nicole to be in lab at unusual hours, often for long periods of time, to make sure that the cells wouldn’t die. “The cells do not wait on you,” she explains, adding, “even if they’re ready at 3am.” Sometimes Nicole worked nights in order to get time on the TIRF. “If you love it, it’s not a sacrifice.”

Why grad school?

As an undergraduate student studying Agricultural Biochemistry at the University of Missouri, Nicole worked in a soybean lab investigating nitrogen fixation, and knew she wanted to pursue research further. She had worked in a lab work since high school, but didn’t realize it was a path she could pursue, instead convinced that she wanted to go to medical school. Nicole’s mom encouraged her to pursue research, because she knew that it was something she enjoyed, and her undergraduate advisor (who completed his post-doc at OSU) suggested that she apply to OSU. She feels lucky to have found an advisor like Colin Johnson, and stresses the importance of finding a mentor who is personally vested in their graduate student’s success.

Besides lab work…

In addition to research, Nicole has been actively involved in outreach to the community, serving as Educational Chair of the local NAACP Chapter. Following completion of her PhD, Nicole intends to continue giving back to the community, by establishing a scholarship program for underrepresented students. Nicole remembers a time when she was told and believed that she wasn’t good enough, and while she was able to overcome this discouraging dialogue, she has observed that many students do not find the necessary support to pursue higher education. Her goal is to reach students who don’t realize they have potential, and provide them with resources for success.

Tune in on December 3rd  at 7pm to 88.7 KBVR Corvallis or stream the show live right here to hear more about Nicole’s journey through graduate school!

Thanks for reading!

You can download Nicole’s iTunes Podcast Episode!

Earlier in the show we discussed current events, specifically how the tax bill moving through the House and Senate impact students. Please see our references and sources for more information.

Tracing Goethe’s influence on botany and plant morphology

As a History of Science PhD student in the School of History, Philosophy, and Religion, Andy Hahn studies how botanists and plant morphologists in the 20th century were influenced by Goethe, a famed German writer and naturalist during the 19th century. Goethe is well known for his rendition of Faust, as well as his novel, The Sorrows of Young Werther. Although historians and philosophers have studied Goethe extensively, his influence on subsequent generations of botanists and plant morphologists has not been fully explored. Goethe wrote a book called Metamorphosis of Plants, which provided early foundational insight into morphology, the study of plant structure and appearance of plant features such as leaves and petals. For his PhD work, Andy has visited institutional archives in Switzerland, England, and Scotland to study the letters and writings of 20th century botanists and other scientists influenced by Goethe’s science.

Goethe’s science was characterized by taking account appearance and structure of plants as a whole entity, as opposed to focusing only specific parts of the plant, a method employed in the taxonomy of Linnaeus, a prominent 18th century natural historian. As the 19th century progressed, Goethe’s approach towards morphology was well-integrated in botanical science in Germany, France, and England. However, the rise of Darwinism, genetics, and experimental methods in the late 19th and early 20th centuries was accompanied by a decreased role for Goethe’s style of morphology. In the early 20th century, plant morphologist community split into two groups: new morphology based in Darwinian thought, and old morphology based in Goethe’s principles. The influence of Goethe’s writing can be seen among botanists in the 20th century, including Agnes Arber, a plant morphologist who translated Goethe’s Metamorphosis of Plants into English.

Andy was introduced to Goethe’s scientific work as he continued to follow his interests that arose from his as an undergraduate in philosophy. He appreciated Goethe’s and current Goethean scientists’ approach to plant morphology as a means to understand the natural world. By visualizing a plant through the course of its life, he was able to develop a stronger connection to the natural world, awakening his own senses by meditating on the form of plants. Andy found himself wondering what happened to the ideas of Goethe, and why Goethe’s ideas weren’t recognized more commonly in biological education. He became interested in philosophical questions surrounding why we think the way we do, as well as the accumulation of knowledge; in particular, how we produce scientific knowledge, and how we can be certain about it. During his Masters studies at OSU, Andy first began researching the botanical work of Goethe, and has continued to study the influence of Goethe on 20th century botanists for his PhD work. Following completion of his graduate studies, Andy would like to teach history of science at the university level and pursue science writing.

To hear more from Andy about the influence of Goethe’s science on botany and plant morphologists, tune in to Inspiration Dissemination on Sunday, October 22 at 7pm on 88.7 KBVR Corvallis. Or stream it online here!

You can download Andy’s iTunes Podcast Episode!

Breaking the Arctic ice

 

Thermal AVHRR image with land masked in black. Can see the lead coming off of Barrow Alaska very bright. The arrows are sea ice drift vectors.

Cascade over mossy rocks near Sol Duc Falls, Olympic National Park, WA.

When you hear about fractures in sea ice, you might visualize the enormous fissures that rupture ice shelves, which release massive icebergs to the sea. This is what happened back in July 2017 when a Delaware-sized iceberg broke off from the Larsen C ice shelf in Antarctica. However, there are other types of fractures occurring in sea ice that may be impacted by atmospheric conditions. Our guest this week, CEOAS Masters student Ben Lewis investigates how interactions between the atmosphere and sea ice in the Beaufort Sea (north of Alaska in the Canadian Archipelago) impact the formation of fractures. His research involves mapping atmospheric features, such as wind and pressure, at the point in time when the fractures occurred and provides insight into the effect of the atmosphere on the formation and propagation of fractures. Utilizing satellite imagery compiled by the Geographical Information Network of Alaska from 1993 to 2013, Ben has conducted a qualitative analysis to determine the location and time when these ice fractures occurred and what type of physical characteristics they possess.

Southern Alps from the summit of Avalanche Peak, New Zealand.

While fractures appear small on the satellite image, the smallest fractures that Ben can observe by are actually 250 meters wide. Fractures can span hundreds of kilometers, and the propagate very quickly; Ben cites one example of a fracture near Barrow, Alaska that grew to 500 kilometers within 6 hours!

Fractures are potentially deadly for people and animals hunting in the Arctic. As weather flux in the fragile Arctic ecosystem has become more erratic with climate change, it has been difficult for people to predict when it was safe to hunt on the ice based on patterns observed in prior seasons. Additionally, it has been problematic to track weather in the Arctic because of its harsh conditions and sparse population. A well-catalogued record of weather is not available for all locations. Modeling atmospheric conditions, such as pressure and wind, based on what has been captured by satelliteimagery, will facilitate better prediction of future fracture events.

Sunset over Sandfly Beach, New Zealand.

While pursuing an undergraduate degree in physics at the University of Arkansas, Ben was able to study abroad James Cook University in Australia, where he gravitated towards environmental physics, while taking advantage of incredible opportunities for nature photography. He also did a semester abroad in New Zealand, where he studied geophysical fluid dynamics and partial differential equations. Ben came to OSU as a post-baccalaureate student in climate science, and while at OSU, he became acquainted with his future PI, Jennifer Hutchings,  and his interest in Arctic research grew. He cites learning about snowball earth, glaciology, and the cryosphere, as providing the basis for his desire to pursue Arctic climate research. Eventually, Ben would like to pursue a PhD, but in the immediate future, he plans to keep his options open for teaching and research opportunities.

 

Using sediment cores to model climate conditions

In the lab of Andreas Schmittner in the College of Earth, Ocean, and Atmospheric Sciences, recently-graduated PhD student Juan Muglia has been developing a climate model to understand ocean current circulation, carbon cycling, and ocean biogeochemistry during the last ice age, focusing on the Southern Ocean surrounding Antarctica.

Juan has developed a climate model using data gathered from sediment cores, which are samples from the ocean floor that provide researchers with a glimpse into the elemental and organic composition of the ocean at different points in time. Scientists can acquire insight into the characteristics of the Earth’s past climate by analyzing the geologic record spanning thousands of years. Modeling the conditions of the last ice age, which occurred 20,000 years ago, allows researchers to better understand how the Earth responds to glacial and interglacial cycles, prompting the transition between cold and warm phases (we are currently in a warm interglacial period).

The process of generating an accurate climate model consists of tuning parameters embedded in the physics equations and fortran code of the model, to reproduce characteristics directly observable in modern times. If researchers can validate their model by reproducing directly observable characteristics, the model can then be used to investigate the climate at points in time beyond our direct observational capacity.

Since it’s not possible to directly measure temperature or nutrient composition of the ocean during the last ice age, Juan uses an indirect signature that serves as a proxy for direct measurement. Three isotopic sediment tracers, including 15Nitrogen, 14Carbon, and 13Carbon, are incorporated into Juan’s climate model as proxies for biological productivity and current circulation in the ocean. Investigating changes in the elemental composition of the ocean, also known as biogeochemistry, is important for understanding how climate and biology have transformed over thousands of years. The ocean serves as an enormous reservoir of carbon, and much more carbon is sequestered in the ocean than in the atmosphere. The exchange of carbon dioxide at the interface of the ocean and atmosphere is important for understanding how carbon dioxide has and will continue to impact pH, ocean currents, and biological productivity of the ocean.

Even as a kid, Juan dreamed of becoming an oceanographer. He grew up near the ocean in Argentina, surrounded by scientists; his mom was a marine botanist and his dad is a geologist. During his undergraduate studies, he majored in physics with the goal of eventually becoming a physical oceanographer, and his undergraduate thesis consisted of building fortran code for a statistical physics project. After finishing his post-doctoral studies at OSU, Juan plans to return to his hometown in Argentina, where he hopes to develop a model specific to the Argentinian climate.

Heliconia: plants with personality

Orange-hatted Dusty Gannon’ (my hummingbird name) visiting Heliconia tortuosa

In the Department of Botany and Plant Pathology, first year graduate student Dusty Gannon is studying how Heliconia tortuosa, a tropical plant with long, tubular flowers and vividly-colored bracts (modified leaves that house the flowers), maintains its unique relationship with pollinating hummingbirds. Although hummingbirds universally love nectar, they have diverged into a few distinct functional groups that are characterized by behavior: traplining hummingbirds repeatedly and circuitously visit flowers, often traveling long distances, while territorial hummingbirds are aggressively possessive of flowers in a home range. It turns out that Heliconia tortuosa is picky about which of these groups contributes to its pollination, and preferentially accepts pollen from traplining hummingbirds, specifically those featuring a long, curved bill. Presumably, their bill shape facilitates maximal nectar extraction which is used as a cue by the plant to become receptive to pollen.  Many hummingbirds visit the Heliconia tortuosa flower, but few induce pollination because of the straight shape of their bill. The shape and size of the Heliconia tortuosa flower in relation to the shape and size of the beak of the pollinator hummingbird constitutes the emergence of a complex plant behavior.

Heliconia wagneriana

Heliconia wagneriana

 

 

 

 

 

 

 

 

 

Dusty’s research is focused on trying to understand how Heliconia tortuosa evolved the capacity to recognize and preferentially invest in pollination by certain pollinator hummingbirds. His work consists of testing for ‘pollinator recognition’ of pollinators across a select subset of species across the Heliconia genus, comprised of 200-250 species, and subsequently using molecular techniques to infer the presence or absence of pollinator recognition across
 the family. Among these several hundred different species of Heliconia, the flowers are morphologically distinct and vary in size from short to long,  straight to curved (even up to a 90-degree angle!). Dusty’s objective is to determine if pollinator recognition is a common trait among morphologically distinct Heliconia species, and uncover the evolutionary significance of this cryptic specialization. While conducting fieldwork at Las Cruces Biological Station in Costa Rica, which featured a garden full of Heliconia, Dusty collected over 1,000 styles (the female reproductive organ in flowering plants) to assay pollen-tube growth rates across various treatments by epi-fluorescence microscopy back at OSU.

Tropical montane forest

Unraveling the tangled evolutionary biology of plants and pollinators is critical for understanding how the loss of certain pollinators might impact plant pollination. If a flower is visited by a variety of different pollinators, the loss of one pollinator might not seem like a big deal. However, if only a small number of the total number of pollinators visiting the flower are capable of inducing pollination, the loss of a true pollinator might be devastating for a plant’s ability to reproduce.

A sample of the morphological diversity in Heliconia flowers

As an undergrad at Colorado State University, Dusty studied Ecosystem Science, which consisted of learning about how nutrients and energy flow through an ecosystem. Dusty cites his high school AP Biology teacher as having a major influence on his desire to study science in college. During the first week of his freshman year, Dusty applied to work in a lab doing DNA barcoding; over the span of 4 years, he conducted over 10,000 PCR reactions! Following completion of his undergrad, Dusty planned to climb mountains in South America for a year, but unexpected circumstances expedited his enrollment in graduate school at OSU to pursue research related to pollinator recognition. Following completion of graduate school, Dusty would like to continue in academia as a professor, and possibly open a bread shop featuring a wood-fired oven, equipped with statistical models to ensure a perfect loaf of bread.

Join us on Sunday May 21st at 7PM on KBVR Corvallis 88.7FM or stream live to hear more about Dusty’s pollinator recognition research and journey through graduate school.

Elucidating protein structure with crystals

Kelsey in the lab pipetting one of her many buffers!

Proteins are the workhorse molecules of the cell, contributing to diverse processes such as eyesight, food breakdown, and disabling of pathogens. Although cells cannot function without helper proteins, they’re so small that it’s impossible to view them without the aid of special tools. Proteins are encoded by RNA, and RNA is encoded by DNA; when DNA is mutated, the downstream structure of the protein can be impacted. When proteins become dysfunctional as part of disease, understanding how and why they behave differently can lead to the development of a therapy. In Andy Karplus’ lab in the Department of Biochemistry & Biophysics, PhD candidate Kelsey Kean uses a technique known as protein x-ray crystallography to study the relationship between protein structure and function.

Protein crystals. On the left, each blade making up this cluster is an individual crystal that needs to be separated before we can use them.

Protein diffraction. An individual crystal is placed in front of an x-ray beam and we collect the diffraction resulting from the x-ray hitting each atom in the protein crystal . Using the position and darkness of each spot (along with some other information), we can figure out where each atom in the crystal was originally positioned.

An electron density map. After collecting and processing our diffraction images, we get an electron density map (blue)- this shows us where all the electrons for each atom in the protein are- and this guides us in building in the atomic coordinates (yellow) for each part of the protein. It’s like a puzzle!

Crystallization of protein involves many steps, each of which presents its own unique challenges. A very pure protein sample is required to form an ordered crystal lattice, and hundreds of different buffer solutions are tested to find the ideal crystallization conditions. Sometimes crystals can take weeks, months, or a year to grow: it all depends on the protein. Once a crystal is obtained, Kelsey ships it to the synchrotron at Lawrence Berkeley National Laboratory, which provides a source of ultra powerful x-ray light beams. Exposure of the protein crystal to x-ray light results in a diffraction pattern, which is caused by the x-ray light diffracting off of all the atoms in the crystal. A map of electron density is generated from the diffraction pattern, and then the electron density map is used to determine where the atoms are located in the protein, like a complex puzzle. X-ray protein crystallography is really amazing because it allows you to visualize proteins at the atomic level!

In addition to her lab work, Kelsey is extensively involved in teaching and STEM outreach. For the past 3 summers, she has organized a week-long summer biochemistry camp through STEM Academy, with the help of a group of biochemistry graduate students. Kelsey has also been involved in Discovering the Scientist Within, a program providing 150 middle school girls with the opportunity to perform science experiments, including isolation of strawberry DNA and working with mutant zebrafish.

Kelsey completed her undergraduate degree in biochemistry with a minor in math at the University of Tulsa, where she was also a Division I athlete in rowing. She attributes her work ethic and time management skills to her involvement in Division I athletics, which required a significant commitment of time and focus outside of lab and coursework. During one summer when she wasn’t busy with competitive rowing, she performed experiments related to protein crystallography at the Hauptman-Woodward Medical Research Institute associated with the University at Buffalo.

Kelsey knew she wanted to pursue science from an early age. She grew up surrounded by scientists: her mom is a biochemist and her dad is a software engineer! She recalls playing with Nalgene squirt bottles as a kid, and participated in the Science Olympiad in middle school, where she engineered a Rube Goldberg machine. She cites early exposure to science from her family as one reason why she feels strongly about STEM outreach to students who might not otherwise receive encouragement or support. In the future, Kelsey would like to teach at a primarily undergraduate institution.

Please join us this Sunday, April 23rd on KBVR Corvallis 88.7FM at 7 pm PST  to hear much more about x-ray protein crystallography, STEM outreach, and to hear an awesome song of Kelsey’s choosing! You can also stream this episode live at www.kbvr.com/listen.

Searching for viruses that make plants sick

Ripening sweet cherries in Mosier, Oregon. Photo credit: Lauri Lutes

When plants get sick, they can’t be treated or cured in the same way as people who receive medicine for an illness.  Plants require specialized care by scientists who are uniquely equipped to study and treat their diseases.  As a graduate student in the lab of Dr. Jay Pscheidt in the Department of Botany and Plant Pathology, Lauri Lutes is a plant doctor looking for viruses that infect sweet cherry trees in Oregon. She is able to identify an infected sweet cherry tree by looking at symptoms, including yellow rings or discolored mottling on the leaves, or fruit that is smaller than normal. To pinpoint the identity of the virus, further tests in the lab are performed.

Mottling and ringspot symptoms on sweet cherry, Prunus avium, in Umpqua Valley, Oregon. Photo Credit: Jay W. Pscheidt

Sweet cherries are one of Oregon’s top commodities, with 12,300 acres of sweet cherry production near the Dalles and Hood River, and 3,200 acres in the Willamette valley. There are a few viruses that the Oregon Department of Agriculture looks for each year, including Plum pox virus, a quarantine pathogen in the United States. However, if sweet cherry trees are infected with something other than the most common or most damaging viruses, they may never receive a diagnosis! Lauri works with the Oregon Sweet Cherry Commission to determine where diseased sweet cherry trees are located in Oregon. During her time at OSU, Lauri has discovered a virus infecting sweet cherry trees in the Dalles region that had never been reported in Oregon!

Lauri Lutes collecting leaf samples from sweet cherry trees in The Dalles, Oregon. Photo credit: Lauri Lutes

As an undergraduate student majoring in biology at Indiana University South Bend, Lauri discovered her passion for plant biology after taking a plant systematics course. Her undergraduate research consisted of studying fungal pathogens in a native waterleaf plant that grows in the forest floor of Indiana. Lauri attributes her positive experiences in undergraduate classes and research to female professors who provided encouragement and strong mentoring. After the birth of her daughter during her senior year of college, Lauri’s path toward attending grad school diverged, and she began working at a plant pathogen diagnostics company, Agdia, Inc. There, she used magnetic particles to purify viruses from plant material and co-developed a Technical Support Department. Curiosity driven, she found that she still wanted a deeper foundation in plant pathology, which led her to pursue graduate work at OSU.

View of Mount Hood from sweet cherry orchard in Parkdale, Oregon. Photo credit: Lauri Lutes

In addition to her work with sweet cherry tree viruses, Lauri is enrolled in the Graduate Certificate in College and University Teaching (GCCUT) program, and is active in science communication, having recently been selected to attend ComSciCon-PNW (Communicating Science Conference) in Seattle. After grad school, Lauri is considering teaching at the university level and continuing her involvement in science communication. As the first person in her family to complete an advanced degree, she hopes to inspire and expose her daughter to educational opportunities she might not have had otherwise.

Please join us this Sunday, April 2nd on KBVR Corvallis 88.7FM at 7 pm PST, to hear much more about Lauri’s journey through grad school, and her research about sweet cherry tree viruses. 

You can also stream this episode live at www.kbvr.com/listen.

View from a sweet cherry orchard in the Hood River, Oregon. Photo credit: Lauri Lutes