Monthly Archives: April 2017

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.

Beetle-Seq: Inferring the Phylogeny of Clivinini

We humans are far outnumbered by organisms that are much smaller and “less complex” than ourselves. The cartoon above depicts representatives of major groups of organisms, and each organism is drawn such that its size reflects the number of species contained within its group. The bird, the fish, and the trees look as expected, but you may notice the enormous beetle. No, beetles are not generally larger than trees or elephants, but there are more species of beetles than any other group of organisms. Beetles are a wonderful representative of the biodiversity of the earth because they can be found in almost every terrestrial and non-marine aquatic environment!

Examples of carabid beetles of the tribe Clivinini (top row; photos with ‘HG’ – Henri Goulet, otherwise – David Maddison). Male genitalia of a clivinine species, Ardistomis obliquata, with possible ‘copulatory weapons’ (right) and several examples of clivinine female genitalia (bottom row) modified from Zookeys 2012;(210):19-67 shared under CC BY 3.0.

Our guest this week, Antonio Gomez from the Department of Integrative Biology, studies a group of beetles called clivinines (pronounced kliv-i-nīnz) which has 1,200 species, and potentially more that have yet to be discovered. Antonio is also particularly interested in the morphological diversity and evolution of clivinine beetle sperm. Antonio wants to know: What is the evolutionary history of clivinine beetles? What is the pattern of morphological diversity of sperm in clivinine beetles, and how are sperm traits evolving? The objective is to collect beetles, study their form, sequence their DNA, and understand their diversification.

Several examples of sperm conjugates (cases where two or more sperm are physically joined and travel together) in carabid beetles. Conjugation is considered rare, but in carabid beetles, it’s the rule and not the exception to it. In many carabids, sperm leave the testis but do not individualize. Instead, they remain together and swim as a team.

This is no small task, but Antonio is well equipped with microscopes to dissect and describe beetle anatomy, a brain geared to pattern recognition, and some fresh tools for genome sequencing. All of this is used to build an evolutionary tree for beetles. This is kind of like a family tree, but with species instead of siblings or cousins. Antonio and other students in the lab of David Maddison are adding knowledge to the vastness of the beetle unknown, bit by bit, antenna by antenna, gene by gene.

Antonio Gomez collecting beetles near a really bright light (a mercury vapor light trap) near Patagonia, Arizona.

Like many of our graduate students at Oregon State, a group of great mentors can make all the difference. Before working with Dr. Kelly Miller at University of New Mexico, he never knew beetle phylogenetics meant exploring exotic locations around the world to collect and potentially discover new species. As an undergraduate, Antonio even named a species of water beetle, Prionohydrus marc, after the undergraduate research program that go him started as a beetle systematist, the Minority Access to Research Careers (MARC) program. Pretty amazing. That was not his first or last research project with insects before he joined ranks at Oregon State, he also was participated in a Research Experience for Undergraduate program at the California Academy of Sciences and completed a Master’s at University of Arizona. Now he has ample experience working with beetles and is maybe a little overwhelmed but still excited by the unknown beetle tree of life. Next on his list of questions: did the ancestor of all clivinines likely have sperm conjugation?

You’ll have to tune in on Sunday April, 16 at 7 pm to hear more about that evolutionary arms race!
Not in Corvallis? No sweat! Stream the show live.

Can’t get enough? Follow this link to learn about Stygoprous oregonensis, a blind subterranean diving beetle that had not been seen in 30 years. Recently, a team of researchers that included Antonio Gomez reported the discovery of more specimens, which allowed them to place Stygoporus in an evolutionary tree.

Just keep swimming or don’t! Curiously following Zebrafish

People often think of science as focusing on very specific questions or rigorous hypothesis testing. However, some of the most exciting advancements were the result of general curiosity of seemingly disparate ideas, and a sprinkle of creativity. For example, the beginnings of how electricity was discovered started by poking frog legs with different types of metals. The modern zero-calorie sugar (saccharin) was discovered by playing creative-chef with coal tar products in the 1870’s when the chemist accidentally tasted his chemical concoction.

Sarah Alto

Our guest this week is using young zebrafish to investigate how environmental factors affect their behavior, and whether behavioral changes can be attributed to specific brain activity. Why zebrafish you may ask? They are a model organisms or they tend to be well studied, relatively easy to breed and maintain in lab settings, and as vertebrates, they share some characteristics with humans. The more we know about zebrafish, the more clues we may have into our own neurobiology. Sarah Alto is exposing these model organisms to different levels of oxygen and carbon dioxide stress. She monitors their swimming with infrared cameras and examines their brain to get an idea of how they respond to stress physically and mentally. This is no easy task because the young zebrafish are only a few millimeters long!

Oxygen, nitrogen, and carbon dioxide gas is bubbled into the tank holding the larvae.
The entire set-up is enclosed in a light-tight box so the larval behavior is more connected to the environment changes and not human interaction.

Curious Sarah is asking: Are low oxygen or high carbon dioxide concentrations changing the swimming behavior of zebrafish? What happens in the brain of a zebrafish when it experiences environmental stress? What can we learn about how environmental factors shape the brain’s connections and influence behavior? Sarah has a long road ahead of her, one that is unpaved with many junctions, but she is performing the exploratory work that may inspire future investigations into the affects of stress on the brain.

The second part of Sarah’s research will be investigating the neural activity when the larvae are exposed to the same gas concentrations as studied in the behavioral experiments.
Image courtesy of Ahrens et al. (2013)

Prior to Sara’s interest in biology, she was always drawn to art as an escape and a method of expression. When choosing which colleges to attend, she didn’t want to choose between art and science. So she chose to pursue both! Sarah enrolled at UC Berkeley as double major including Molecular and Cellular Biology, as well as Practice of Art. The San Francisco art scene was highly accessible, and Berkeley is a top-flight university for the sciences. Needless to say she flourished in this environment and her love of science grew but her love of art continues to this day. Finishing her schooling she began working at UC San Francisco, a premier medical research university, investigating the role of stem cells in facial development to for possible medical treatments for facial reconstruction. She was involved in a variety of projects but her gut feeling led her to continue schooling at Oregon State.

Sarah is now a part of Dr. James Strother’s lab in the College of Science within the department of Integrative Biology focusing the behavioral neurobiology of zebrafish. Be sure to tune in Sunday April 9th at 7PM PST on 88.7FM or listen live.

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