Biology Commons^™

Effect Of A Coevolved Parasitic Nematode On Fitness Of The Desert Horned Lizard (Phrynosoma Platyrhinos), Holly Flann

WWU Graduate School Collection

In the Alvord Desert in Harney County, Oregon, I examined the response of desert horned lizards (Phrynosoma platyrhinos) to a common and abundant gastrointestinal nematode parasite (Skrjabinoptera phrynosoma) transmitted to them through harvester ants (Pogonomyrmex californicus), a principal component of their specialized diet. I examined presumed fitness correlates including foraging, prey choice, energetic endurance, and immune response at varying levels of nematode load in joules/hour while correcting for body size differences in 19 male and 21 female Desert horned lizards in summer 2018. The effects of increasing nematode load were more benign than hypothesized, …

Genomic Insights And Ecological Adaptations Of Deep-Subsurface And Near Subsurface Thermococcus Isolates, Lilja Caitlin Strang

WWU Graduate School Collection

Members of the Archaeal genus Thermococcus are sulfur-dependent hyperthermophiles found in hydrothermal vents throughout the world. Previous analysis of a Thermococcus culture collection containing isolates from the Juan de Fuca Ridge, Gorda Ridge, and South East Pacific Rise using amplified fragment length polymorphism analysis and multilocus sequence typing revealed a distinct clade of Thermococcus isolated from the 1996 megaplume event at Gorda Ridge, indicating that they originated from a deep-subsurface habitat. The aim of this study was to elucidate the functional adaptations that allow for the survival of the Gorda Ridge clade in a deepsubsurface habitat as compared to representative …

Survival, Growth, And Radula Morphology Of Postlarval Pinto Abalone (Haliotis Kamtschatkana) When Fed Six Species Of Benthic Diatoms, Lillian Miller Kuehl

WWU Graduate School Collection

Haliotis kamtschatkana Jonas (pinto or northern abalone) is the only abalone native to the Pacific Northwest of North America. Haliotis kamtschatkana populations are in decline, and current restoration efforts in Washington State rely on out-planting hatchery-produced juveniles. Although several other abalone species are cultured extensively, little information exists on the cultivation of H. kamtschatkana, and hatchery production of this species has largely been a matter of trial and error. Hatcheries report highest mortalities in the postlarval stage, especially the first 3 to 6 months. Postlarvae feed on films of benthic diatoms, and the purpose of this study was to …

Neural Signaling Dynamics Of Conditioning In C. Elegans, Micaela R. Pribic

WWU Graduate School Collection

Retrograde signaling from downstream effectors (i.e., motor neurons) can modulate plasticity. Much research has focused on the learned association of closely timed sensory stimuli. By comparison, there is less research probing the potential influence of how or if activation at downstream neuromuscular junctions (NMJ) could modulate associative conditioning. Using channelrhodopsin activation of body wall muscle and different motor neuron subsets (cholinergic motor neurons that drive contraction and GABAergic motor neurons that drive relaxation of muscle) in the Caenorhabditis elegans (C. elegans) model system, we examined if concurrent excitation in these downstream circuits influences associative conditioning.

Conditioning consisted of pairing two …

Comparing The Bioavailability Of A Natural And Synthetic Iron Source: Do Past Experiments Accurately Model Phytoplankton Response To Episodic Iron Addition?, Clayton Mazur

WWU Graduate School Collection

Episodic iron input from natural sources (e.g., riverine input, dust deposition, and mesoscale eddies) plays an important role in dictating phytoplankton growth, physiology, and community structure in the high-nitrate low-chlorophyll (HNLC) waters of the Northern Gulf of Alaska (NGA). Iron addition experiments utilizing the synthetic iron source, FeCl₃, have been performed in all major HNLC regions and have resulted in diatom blooms with significant implications for ecosystem productivity and resilience. If FeCl₃ and natural iron sources differ in bioavailability, and hence potential phytoplankton production, re-interpretation of these results is warranted. To test the hypothesis that natural and …

Investigating The Effects Of Climate Co-Stressors On Surf Smelt Energy Demands, Megan Russell

WWU Graduate School Collection

Surf smelt (Hypomesus pretiosus) are ecologically and economically important to the Pacific Northwest. They play a critical role in the food web and support numerous commercially important species and are an economically important baitfish. Surf smelt interact closely with the nearshore environment, utilizing approximately 10% of Puget Sound coastlines for spawning throughout the year. Surf smelt spawn at high tide and adhere fertilized eggs to beach sediment, causing their embryos to be exposed to air and seawater throughout embryonic development. Because of this unique life history, surf smelt may be susceptible to anthropogenic stressors including coastal development and …

Community Structure Of Benthic Microbial Mats At Hydrothermal Springs In Crater Lake, Oregon, Amanda Stromecki

WWU Graduate School Collection

Crater Lake, Oregon is an oligotrophic freshwater caldera lake fed by thermally and chemically-enriched hydrothermal springs. These vents distinguish Crater Lake from other freshwater systems and provide a unique ecosystem for study. This study examines the microbial community structure of hydrothermal mat communities found in the bottom of Crater Lake. Small subunit rRNA gene amplicon sequencing from eight microbial mats was used to assess community structure. These findings revealed a relatively homogeneous, yet diverse bacterial community. High alpha diversity and low beta diversity indicates that these communities are likely fueled by homogeneous and consistent hydrothermal fluids. An examination of autotrophic …

Codon Bias And Mrna Folding Stability: Two Natural Controls Of Protein Expression Dynamics, Anastacia Wienecke

WWU Graduate School Collection

Introduction: Connections between genetic variation and trait variation are complex and dynamic; the critical link between the two is gene expression variation. Though proteins are the functional products of most genes, the relative ease and throughput level of various measurement approaches has meant that gene expression is typically studied via transcript-level rather than protein-level techniques. Recent studies however, suggest that certain genetic factors act post-transcriptionally to modify rates of protein synthesis, making transcript levels imperfect indicators of protein levels. A gene’s bias for ‘optimal’ codons (i.e., its codon bias) and a gene’s mRNA folding stability appear to be two such …

Regulation Of Glutamate Receptor (Glr-1) Under Endoplasmic Reticulum Stress In Caenorhabditis Elegans, Janie Aguilera

WWU Graduate School Collection

Neurons communicate with other cells to elicit outputs that include memory and movement. Cells, including neurons, create proteins every day for specific functions and in particular, neurons produce proteins that enable their communication. Proteins found in cellular membranes are synthesized at the endoplasmic reticulum (ER). However, up to 30% of new proteins are improperly folded and must be removed from the cell. A build-up of misfolded proteins can trigger the Unfolded Protein Response (UPR) which initiates other pathways of protein quality control and can determine the fate of a cell. ER-associated protein degradation (ERAD) is a ubiquitin-dependent process in eukaryotic …

The Impacts Of Sex-Specific Diets Of A Marine Predator On Ecosystem Models, Jonathan Blubaugh

WWU Graduate School Collection

Ecosystem modeling is an increasingly popular method to understand how organisms within ecosystems interact, relying on robust data incorporating important inter- and intraspecies interactions to predict ecosystem changes. However, no study has included sex-specific intrapopulation variation in an ecosystem model. In the well-studied Salish Sea, harbor seals (Phoca vitulina) are an important marine mammal that have significant sex-specific diet variability, which I hypothesized would have indirect effects on other functional groups in the region. Male harbor seals consume a higher diet proportion of salmon, while female harbor seals consume a higher proportion of herring and small demersal fish. …

A Non-Invasive Technique For Tracking A Marine Predator (Phoca Vitulina) Through Molecular Scat Analysis, Nathaniel Guilford

WWU Graduate School Collection

As ecosystems are subjected to increased urbanization, habitat loss, and resource depletion, management practices will benefit from higher resolution models of local trophic dynamics. Harbor seals (Phoca vitulina), the most abundant marine mammal in the Salish Sea of British Columbia and Washington State, are of great regional interest due to their consumption of species of conservation concern such as Chinook salmon (Oncorhynchus tshawytscha) and Pacific herring (Clupea pallasii). This ecologically influential diet can vary with season, region, and local sex ratios, creating localized pressures on prey species. Variation in diet has been observed at …