Biology Commons^™

Investigating Dose-Dependent, Multi-Generational, And Strain-Specific Effects Of 17Α-Ethynylestradiol Exposure In Zebrafish (Danio Rerio), Decatur Mitochondria Foster

Dissertations and Theses

Endocrine disrupting chemicals (EDCs) pose a threat to biodiversity at the individual, population, and ecosystem level, as they can interfere with processes that are responsible for regulating metabolism, development, behavior, and reproduction in living organisms. 17α-ethynylestradiol (EE2) is a synthetic estrogen and EDC utilized in pharmaceutical and livestock industries, and contaminates waterways worldwide. This research explores the effects of dose-dependent and multi-generational exposure of EE2 in three strains of zebrafish. High dose (10-25 ng/L EE2) exposure led to complete reproductive failure, as well as significantly decreased survival and growth. A period in clean water (depuration) after exposure allowed for some …

Editor's Choice: Aldo Leopold Conservation Award, Luis A. Ruedas

Biology Faculty Publications and Presentations

Every year since 2003, the American Society of Mammalogists confers during its annual meeting the Aldo Leopold Conservation Award on a highly deserving individual. A consequence of the award for the awardee is the responsibility to write a feature article in the pages of this journal. Aldo Leopold, the namesake of the award, is considered by an overwhelming majority of biologists to be the father of contemporary conservation biology. Born in Burlington, Iowa, Leopold graduated with a Master’s degree from the Yale Forest School, which had been endowed in 1902 by the Pinchot family and was one of the first …

Pathology Findings And Correlation With Body Condition Index In Stranded Killer Whales (Orcinus Orca) In The Northeastern Pacific And Hawaii From 2004 To 2013, Stephen A. Raverty, Judy St. Leger, Dawn P. Noren, Kathy Burek Huntington, David S. Rotstein, Francis M.D. Gulland,, Deborah A. Duffield, Multiple Additional Authors

Biology Faculty Publications and Presentations

Understanding health and mortality in killer whales (Orcinus orca) is crucial for management and conservation actions. We reviewed pathology reports from 53 animals that stranded in the eastern Pacific Ocean and Hawaii between 2004 and 2013 and used data from 35 animals that stranded from 2001 to 2017 to assess association with morphometrics, blubber thickness, body condition and cause of death. Of the 53 cases, cause of death was determined for 22 (42%) and nine additional animals demonstrated findings of significant importance for population health. Causes of calf mortalities included infectious disease, nutritional, and congenital malformations. Mortalities in sub-adults were …

Novel Small Rnas Expressed By Bartonella Bacilliformis Under Multiple Conditions Reveal Potential Mechanisms For Persistence In The Sand Fly Vector And Human Host, Shaun Wachter, Linda D. Hicks, Rahul Raghavan, Michael F. Minnick

Biology Faculty Publications and Presentations

Bartonella bacilliformis, the etiological agent of Carrión’s disease, is a Gram-negative, facultative intracellular alphaproteobacterium. Carrión’s disease is an emerging but neglected tropical illness endemic to Peru, Colombia, and Ecuador. B. bacilliformis is spread between humans through the bite of female phlebotomine sand flies. As a result, the pathogen encounters significant and repeated environmental shifts during its life cycle, including changes in pH and temperature. In most bacteria, small non-coding RNAs (sRNAs) serve as effectors that may post-transcriptionally regulate the stress response to such changes. However, sRNAs have not been characterized in B. bacilliformis, to date. We …

Direct Binding Of Tfeα Opens Dna Binding Cleft Of Rna Polymeras, Sung-Hoon Jun, Jaekyung Hyun, Hoyoung Kim, Michael S. Bartlett, Hyun-Soo Cho, Katsuhiko S. Murakami

Biology Faculty Publications and Presentations

Opening of the DNA binding cleft of cellular RNA polymerase (RNAP) is necessary for transcription initiation but the underlying molecular mechanism is not known. Here, we report on the cryo-electron microscopy structures of the RNAP, RNAP-TFEα binary, and RNAPTFEα-promoter DNA ternary complexes from archaea, Thermococcus kodakarensis (Tko). The structures reveal that TFEα bridges the RNAP clamp and stalk domains to open the DNA binding cleft. Positioning of promoter DNA into the cleft closes it while maintaining the TFEα interactions with the RNAP mobile modules. The structures and photo-crosslinking results also suggest that the conserved aromatic residue in the extended winged-helix …

Landscape Genetics Of Plants: Challenges And Opportunities, Mitchell Cruzan, Elizabeth C. Hendrickson

Biology Faculty Publications and Presentations

Dispersal is one of the most important but least understood processes in plant ecology and evolutionary biology. Dispersal of seeds maintains and establishes populations, and pollen and seed dispersal are responsible for gene flow within and among populations. Traditional views of dispersal and gene flow assume models that are governed solely by geographic distance and do not account for variation in dispersal vector behavior in response to heterogenous landscapes. Landscape genetics integrates population genetics with Geographic Information Systems (GIS) to evaluate the effects of landscape features on gene flow patterns (effective dispersal). Surprisingly, relatively few landscape genetic studies have been …

Gaba Metabolism Is Crucial For Long-Term Survival Of Anoxia In Annual Killifish Embryos, Daniel E. Zajic, Jason Podrabsky

Biology Faculty Publications and Presentations

In most vertebrates, a lack of oxygen quickly leads to irreparable damages to vital organs, such as the brain and heart. However, there are some vertebrates that have evolved mechanisms to survive periods of no oxygen (anoxia). The annual killifish (Austrofundulus limnaeus) survives in ephemeral ponds in the coastal deserts of Venezuela and their embryos have the remarkable ability to tolerate anoxia for months. When exposed to anoxia, embryos of A. limnaeus respond by producing significant amounts of γ-aminobutyric acid (GABA). This study aims to understand the role of GABA in supporting the metabolic response to anoxia. To explore this, …

A Rapid Caspase-11 Response Induced By Ifng Priming Is Independent Of Guanylate Binding Proteins, Sky W. Brubaker, Susan M. Brewer, Liliana M. Massis, Brooke A. Napier, Denise M. Monack

Biology Faculty Publications and Presentations

In mammalian cells, inflammatory caspases detect Gram-negative bacterial invasion by binding lipopolysaccharides (LPS). Murine caspase-11 binds cytosolic LPS, stimulates pyroptotic cell death, and drives sepsis pathogenesis. Extracellular priming factors enhance caspase-11-dependent pyroptosis. Herein we compare priming agents and demonstrate that IFNγ priming elicits the most rapid and amplified macrophage response to cytosolic LPS. Previous studies indicate that IFN-induced expression of caspase-11 and guanylate binding proteins (GBPs) are causal events explaining the effects of priming on cytosolic LPS sensing. We demonstrate that these events cannot fully account for the increased response triggered by IFNγ treatment. Indeed, IFNγ priming …

Best Practices For Successfully Writing And Publishing A Genome Announcement In Microbiology Resource Announcements, Julie C. Dunning Hotopp, David A. Baltrus, Vincent M. Bruno, John J. Dennehy, Steven R. Gill, Julia A. Maresca, Jelle Matthijnssens, Irene L. J. Newton, Catherine Putonti, David A. Rasko, Antonis Rokas, Simon Roux, Jason E. Stajich, Kenneth M. Stedman, Frank J. Stewart, J. Cameron Thrash

Biology Faculty Publications and Presentations

Microbiology Resource Announcements (MRA) provides peer-reviewed announcements of scientific resources for the microbial research community. We describe the best practices for writing an announcement that ensures that these publications are truly useful resources. Adhering to these best practices can lead to successful publication without the need for extensive revisions.

From Theory To Practice: Gathering Evidence For The Validity Of Data Collected With The Interdisciplinary Science Rubric (Idsr)., Brie Tripp, Erin E. Shortlidge

Biology Faculty Publications and Presentations

In a world of burgeoning societal issues, future scientists must be equipped to work inter-disciplinarily to address real-world problems. To train undergraduate students toward this end, practitioners must also have quality assessment tools to measure students' ability to think within an interdisciplinary system. There is, however, a dearth of instruments that accurately measure this competency. Using a theoretically and empirically based model, we developed an instrument, the Interdisciplinary Science Rubric (IDSR), to measure undergraduate students' interdisciplinary science thinking. An essay assignment was administered to 102 students across five courses at three different institutions. Students' work was scored with the newly …

Battle Of The Buttercups: Investigating Hybrid Zone Dynamics In A Ranunculus Species Complex, Jessica Persinger

Dissertations and Theses

Plants pose a well-known challenge to the biological species concept because hybridization is a common occurrence. Range dynamics have a crucial role in determining whether species are given the opportunity to interbreed or not. Successful hybridization can be of particular concern when considering range-limited species and their persistence. In my thesis research, I examine the apparent hybrid zone between the southern Oregon endemic Ranunculus austro-oreganus, a candidate threatened species due to its limited range, and its widespread congener, Ranunculus occidentalis, whose range spans from California to Alaska. The discovered contact zone was recognized in populations which contained apparent …

No Water, No Problem: Stage-Specific Metabolic Responses To Dehydration Stress In Annual Killifish Embryos, Daniel E. Zajic, Jonathon P. Nicholson, Jason Podrabsky

Biology Faculty Publications and Presentations

Annual killifish survive in temporary ponds by producing drought-tolerant embryos that can enter metabolic dormancy (diapause). Survival of dehydration stress is achieved through severe reduction of evaporative water loss. We assessed dehydration stress tolerance in diapausing and developing embryos. We measured oxygen consumption rates under aquatic and aerial conditions to test the hypothesis that there is a trade-off between water retention and oxygen permeability. Diapausing embryos survive dehydrating conditions for over 1.5 years, and post-diapause stages can survive over 100 days. Diapausing embryos respond to dehydration stress by increasing oxygen consumption rates while post-diapause embryos exhibit the same or reduced …

Metabolomics Analysis Of Annual Killifish (Austrofundulus Limnaeus) Embryos During Aerial Dehydration Stress, Daniel Zajic, Jason Podrabsky

Biology Faculty Publications and Presentations

The annual killifish, Austrofundulus limnaeus, survives in ephemeral ponds in the coastal deserts of Venezuela. Persistence through the dry season is dependent on drought-resistant eggs embedded in the pond sediments during the rainy season. The ability of these embryos to enter drastic metabolic dormancy (diapause) during normal development enables A. limnaeus to survive conditions lethal to most other aquatic vertebrates; critical to the survival of the species is the ability of embryos to survive months and perhaps years without access to liquid water. Little is known about the molecular mechanisms that aid in survival of the dry season. This study …

Assessing Well-Being Of Asian Elephants (Elephas Maximus) Through Major Events And Transitions, With Development And Aging, And Husbandry Changes, Sharon Stuart Glaeser

Dissertations and Theses

In this body of research, reproductive and adrenal hormones and behavior were used to evaluate individual and group responses to physiological, social, and environmental changes in zoo-housed Asian elephants, considering factors of sex, age, and life stage. Animals experience physiological, social, and environmental changes as part of their natural history and individual life experience. Measures of both positive and negative states are needed to assess the impact of these changes at the individual and group level. Such measures can help us better understand how animals cope with a changing environment, and can help inform management decisions. Through longitudinal analyses of …

Energy Stores And Life-History Transitions In Red-Sided Garter Snakes (Thamnophis Sirtalis Parietalis), Rachel Catharine Wilson

Dissertations and Theses

All organisms must prioritize investment in either reproductive or self-maintenance activities. Despite this established paradigm, our understanding of how organisms choose to prioritize certain behaviors and physiologies over others remains limited. It is likely that an organism's energy status not only influences variation in reproductive effort, but also transitions to and from reproductive activities. My dissertation aims to investigate how energy metrics (body condition index, adipocyte follicle size, and liver glycogen) relate to reproduction and associated life-history stages in red-sided garter snakes (Thamnophis sirtalis parietalis). Chapter two examines if energy metrics differ with migratory status and sex in …

Short- And Long-Term Impacts Of A Deliberative Pedagogy In Introductory Biology And Chemistry Courses, Liz Rain-Griffith

Dissertations and Theses

There have been multiple national calls for curricular reform in college-level science, technology, engineering, and mathematics (STEM), including a need to instill democratic skills in students. Democratic skill building can be embedded in STEM classrooms through intentional "deliberative pedagogies" which include skills in: communication, collaboration, and application. We developed and implemented a deliberative pedagogy, Deliberative Democracy (DD), across introductory majors and non-majors biology courses and a majors chemistry course. In two separate studies, I took a longitudinal, qualitative research approach to understand introductory biology and chemistry students' experiences and perceptions of DD. For the first study, I tracked a cohort …

No Oxygen, No Water: The Unique Physiology Of Annual Killifish Embryos Across Development, Daniel Erik Zajic

Dissertations and Theses

For most vertebrates, an abundance of oxygen is necessary for the production of ATP and the maintenance of cellular homeostasis. The absence of oxygen, even for brief periods, quickly leads to ATP depletion which can lead to irreparable damages to sensitive organs, such as the brain and heart. However, certain vertebrates demonstrate an extraordinary ability to thrive and recover fully from periods of no oxygen (anoxia). The annual killifish (Austrofundulus limnaeus) lives in ephemeral ponds in the Maracaibo basin of Venezuela and their embryos have the remarkable ability to not only survive anoxic periods for months, but also …

Sensing Malignancy: Expanding Upon The Nematode Scent Detection Test, Morgan Alexandra Thompson

Dissertations and Theses

With the growing prevalence of cancer worldwide, research has increasingly focused on methods of early detection since the early detection of cancer can dramatically improve health outcomes for affected individuals. Ideally, early detection systems would be highly reliable yet cost-effective and easy to use. Toward development of such a system, Hirotsu et al. (2015), developed a "Nematode Scent Detection Test" (NSDT) that capitalizes upon the attraction of Caenorhabditis elegans nematodes to various tissue samples from cancer patients to detect multiple types and stages of cancer. However, it is currently unknown which G-protein coupled receptors (GPCRs), and/or ligands interacting with theses …

Morphology, Taxonomy, And Ecological Niche Modeling Of The Cochabamba Grass Mouse, Akodon Siberiae Myers & Patton, 1989, James George Dunn

Dissertations and Theses

The Cochabamba Grass Mouse, Akodon siberiae, is a small mouse (mean head+body length: 103 mm, N = 22) that occurs in a spatially restricted range in the Bolivian Yungas forests, the cloud forest transition zone between lowland Amazonia and the Andean Altiplano. Like many species in the genus, their appearance is very similar to that of other species in the genus: they are difficult to distinguish from their congeners, and are challenging to identify. In the absence of molecular data, A. siberiae specimens require a thorough and careful analysis of external and cranial features for identification. Furthermore, Akodon …

Biogeography, Morphology, And Systematics Of The Mountain Cottontail, Sylvilagus Nuttallii (Bachman, 1837), Mammalia: Lagomorpha: Leporidae, Johnnie H. French

Dissertations and Theses

Widespread species often present taxonomic conundrums: are they truly a single panmictic species, or, is the widespread species in fact a polytypic species complex constituted by independently evolving, morphologically or otherwise cryptic species? One such broadly distributed taxon is Sylvilagus nuttallii, with distribution across the western United States, ranging from South Dakota to California, and from Canada to Arizona. The three subspecies constituting S. nuttallii are, however, geographically isolated and it has been hypothesized that they likely constitute independent, species level taxa. However, that study examined only two of the three holotypes, rather than broader geographic and non-geographic variation. …

Host-Dependent Differences In Replication Strategy Of The Sulfolobus Spindle-Shaped Virus Strain Ssv9 (A.K.A., Ssvk1): Infection Profiles In Hosts Of The Family Sulfolobaceae, Ruben M. Ceballos, Coyne Gareth Drummond, Carson Len Stacy, Elizabeth Padillo-Crespo, Kenneth M. Stedman

Biology Faculty Publications and Presentations

The Sulfolobus Spindle-shaped Virus (SSV) system has become a model for studying thermophilic virus biology, including archaeal host-virus interactions and biogeography. Several factors make the SSV system amenable to studying archaeal genetic mechanisms (e.g., CRISPRs) as well as virus-host interactions in high temperature acidic environments. Previously, we reported that SSVs exhibited differential infectivity on allopatric vs. sympatric hosts. We also noticed a wide host range for virus strain SSV9 (a.k.a., SSVK1). For decades, SSVs have been described as “non-lytic” double-stranded DNA viruses that infect species of the genus Sulfolobus and release virions via budding rather than host lysis. In this …

Undergraduate Biology Education Research Gordon Research Conference: A Meeting Report, Erin L. Dolan, Michelle Borrero, Kristine Callis-Duehl, Miranda M. Chen Musgrove, Joelyn De Lima, Isi Ero-Tolliver, Laci M. Gerhart, Emma Goodwin, Lindsey R. Hamilton, Meredith A. Henry, Jose Herrera, Bethany Huot, Stacey Kiser, Melissa E. Ko, Marcy E. Kravec, Mark Lee, Lisa B. Limeri, Melanie E. Peffer, Debra Pires, Juan S. Ramirez Lugo, Starlette M. Sharp, Nicole A. Suarez

Biology Faculty Publications and Presentations

The 2019 Undergraduate Biology Education Research Gordon Research Conference (UBER GRC), titled “Achieving Widespread Improvement in Undergraduate Education,” brought together a diverse group of researchers and practitioners working to identify, promote, and understand widespread adoption of evidence-based teaching, learning, and success strategies in undergraduate biology. Graduate students and postdocs had the additional opportunity to present and discuss research during a Gordon Research Seminar (GRS) that preceded the GRC. This report provides a broad overview of the UBER GRC and GRS and highlights major themes that cut across invited talks, poster presentations, and informal discussions. Such themes include the importance of …

Pre-Emptive Detection Of Mature Pine Drought Stress Using Multispectral Aerial Imagery, Nancy Grulke, Jason Maxfield, Phillip Riggan, Charlie Schrader-Patton

Biology Faculty Publications and Presentations

Drought, ozone (O₃), and nitrogen deposition (N) alter foliar pigments and tree crown structure that may be remotely detectable. Remote sensing tools are needed that pre-emptively identify trees susceptible to environmental stresses could inform forest managers in advance of tree mortality risk. Jeffrey pine, a component of the economically important and widespread western yellow pine in North America was investigated in the southern Sierra Nevada. Transpiration of mature trees differed by 20% between microsites with adequate (mesic (M)) vs. limited (xeric (X)) water availability as described in a previous study. In this study, in-the-crown morphological traits (needle chlorosis, …

From Theory To Practice: Interdisciplinary Science In Undergraduate Education, Brie Tripp

Dissertations and Theses

Science has undergone a major transformation in the 20th and 21st centuries with new fields emerging at the intersection of disciplines, such as bioethics, bioinformatics, and chemical ecology. Yet, opportunities to engage with interdisciplinary science, and the skills needed to work in these fields, are largely absent from undergraduate biology classrooms. As a consequence, students are potentially deprived of opportunities to think interdisciplinarily and engage with real-world issues that often necessitate interdisciplinary efforts. To be informed citizens in society and forward-thinking scientists in the workforce, undergraduate students will undoubtedly benefit from exposure to these interdisciplinary science experiences.

Given these considerations, …

Lack Of Replication Disruption Following H2o2-Induced Damage In Escherichia Coli, Sierra S. Schmidt, Justin Courcelle, Charmain T. Courcelle

University Honors Theses

Hydrogen peroxide (H₂O₂) toxicity has long been thought to be predominantly due to oxidative DNA damage that can disrupt DNA replication and result in lethality. Curiously and contrary to this view, it is also well established that the glycosylases responsible for repairing oxidized-base damage are as resistant as wild-type cells when treated with H₂O₂. The observation raises the possibility that H₂O₂-induced DNA damage does not disrupt or prevent replication. To examine this possibility, I examined the sensitivity of recF mutants to H₂O₂. RecF is …

Developmental Programming Effects Of Maternal Obesity, Carolle J. Kassab

University Honors Theses

Population studies within the United States indicate increasing rates of obesity, considerably prominent for women within reproductive age. Maternal obesity is associated with the offspring’s hyperlipidemia, diabetes, and cardiovascular disease, which have chronic consequences. Obesity in pregnancy causes metabolic and epigenetic perturbations within the fetal environment, disrupting future health of offspring. This phenomenon is known as developmental programming. Although the relationship between maternal undernutrition and developmental programming has been demonstrated, its relationship to maternal obesity remains understudied.

Long Term Effects Of Concussions And The Frequency Of Injury To The Different Regions Of The Human Brain, Marissa S. Swadener

University Honors Theses

Concussions, or mild traumatic brain injuries, do not have a universally accepted definition but there are key features that the experts agree upon; most notably that they are caused by a direct blow, they cause functional disturbances, and that they cannot be explained by another injury or impairment. Most concussions are resolved within a few days but 10-20% have lingering effects that can last for years. In this study, frequency of lingering injury to each brain region was determined from data from thirteen studies and compared to Scheid et. al's frequency of short term injury by brain region using ANOVA …

Screening For Candidate Genes Involved In Opioid Addiction In Reduced Complexity Cross Between B6j And B6nj, Jeya Aishwarya Anandakumar

University Honors Theses

Drug overdose epidemic has worsened dramatically in the past 10 years. Opioid use disorder (OUD) is one of the biggest contributors to this rise. OUD has been a national public health and socioeconomic crisis. In 2017, the Center for Disease Control (CDC) has reported 47,600 opioid overdose deaths in the US alone. This amounts to 68% of all deaths due to drug overdose. Currently, 2.1 million Americans are suffering from OUD. The economic burden due to opioid misuse treatment was 171.7 billion US dollars in the year 2009 in the U.S. The projected cost in 2020 will be 280.5 billion …

Proposal For Comparative Morphometrics Of Tübingen (Tu) And Tübingen Longfin (Tl) Zebrafish (Danio Rerio), Andrew Draper

University Honors Theses

The TL strain of zebrafish (Danio rerio) originated from the TU strain, and differs in fin pattern with a phenotype predominated by increased fin length. Two genes are known to affect the phenotype: leo and lof. The pattern-affecting leo gene is not believed to affect the growth rate, development, or proportionality of the body. The lof gene does however result in significant increase in fin length compared to the wild-type phenotype of TU. Using populations from both TL and TU genetic strains, development was observed from 48 hours post fertilization through sexual maturity at 90 days post fertilization …

Effects Of Management For Productivity On Adult Survival Of Snowy Plovers, Eleanor P. Gaines, Stephen J. Dinsmore, Michael T. Murphy

Biology Faculty Publications and Presentations

Understanding the factors contributing to variation in demographic parameters and their influences on population growth is fundamental to effective conservation of small populations, but this information is often not available. Among shorebirds, population growth is generally most sensitive to changes in adult survival so understanding the factors affecting this vital rate is important. We used a long‐term mark–resight dataset and Program MARK to examine the effect of management actions, initiated to improve nesting productivity, on adult survival in a threatened population of Snowy Plovers (Charadrius nivosus ) in Oregon, USA. Apparent adult survival averaged 0.71 ± 0.01 (SE), but …