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Theses/Dissertations

2013

Biology

WWU Graduate School Collection

Articles 1 - 6 of 6

Full-Text Articles in Life Sciences

The Effects Of Elevated Temperature And Ocean Acidity On Bacterioplankton Community Structure And Metabolism, Nam Siu Jan 2013

The Effects Of Elevated Temperature And Ocean Acidity On Bacterioplankton Community Structure And Metabolism, Nam Siu

WWU Graduate School Collection

By the end of the 21st century, mean sea surface temperatures are expected to increase 4°C, while atmospheric CO2 concentrations are predicted to triple causing seawater to become more acidic. These compounding effects will undoubtedly have major consequences for the organisms and processes in the oceans. Bacterioplankton play a vital role in the marine carbon cycle and the oceans' ability to sequester CO2. We utilized pCO2 perturbation experiments to investigate the effects of elevated temperature and acidity on bacterioplankton community structure and metabolism. Terminalrestriction fragment length polymorphism (T-RFLP) revealed that bacterioplankton incubated in lower pH conditions exhibited a reduction ...


Identification Of Proteins That Putatively Bind The Promoter Of The Stomatal Master Regulator Gene, Mute, Anthony F. (Anthony Fahike) Williams Jan 2013

Identification Of Proteins That Putatively Bind The Promoter Of The Stomatal Master Regulator Gene, Mute, Anthony F. (Anthony Fahike) Williams

WWU Graduate School Collection

Stomata are epidermal pores on land plants that exchange gases to maintain water potential and photosynthesis. Two guard cells flank each pore and change the aperture based on turgor pressure-induced changes in their shape. Stomatal aperture and density are affected by environmental stimuli such as light quality and quantity, CO2 concentrations, and water availability. The basic helix-loop-helix (bHLH) transcription factor MUTE drives the differentiation of transient epidermal stem cells, called meristemoids, to guard mother cells, which divide to form a mature stoma. MUTE is only transcriptionally active in late-stage meristemoids, but the mechanisms controlling its expression are unknown. The purpose ...


Short-Range Host Preference In Snowberry Maggot Flies Depends On Life History Stage, John L. (John Lawton) Huddleston Jan 2013

Short-Range Host Preference In Snowberry Maggot Flies Depends On Life History Stage, John L. (John Lawton) Huddleston

WWU Graduate School Collection

Closely related animal species are often incompletely isolated reproductively and occasionally hybridize. Many host-specific insects are primarily isolated by the reproductive barrier of host choice and provide model systems to study gene flow in sympatry. Understanding conditions that alter barriers like host choice can help us understand reproductive isolation between these species. Hybridization occurs between microsympatric populations of apple and snowberry maggots in Bellingham, Washington which are also not isolated by mating season or assortative mating. I exposed apple and snowberry maggots to their natal fruits in two-way choice experiments to measure their short-range host preferences. I tested snowberry flies ...


Physiological Adaptations And Feeding Mechanisms Of The Invasive Purple Varnish Clam, Nuttallia Obscurata, Leesa E. Sorber Jan 2013

Physiological Adaptations And Feeding Mechanisms Of The Invasive Purple Varnish Clam, Nuttallia Obscurata, Leesa E. Sorber

WWU Graduate School Collection

The Purple Varnish Clam, Nuttallia obscurata, is an example of a recent successful invader to the Pacific Northwest. Nuttallia obscurata reside in the high intertidal zone where it must adapt to daily and seasonal fluctuations in salinity and food availability. I investigated their physiological and morphological adaptations to these conditions. The acute physiological response of the invasive, N. obscurata and the native, L. staminea's excised gill tissue's respiratory metabolism (measured as oxygen consumption) in 5, 30, and 55 ppt salinities were measured in a closed system, Gilson Differential Respirometer and compared. The excised gill tissue of both species ...


Biogeography And Evolution Of Thermococcus Isolates From Hydrothermal Vent Systems Of The Pacific, Mark T. (Mark Thomas) Price Jan 2013

Biogeography And Evolution Of Thermococcus Isolates From Hydrothermal Vent Systems Of The Pacific, Mark T. (Mark Thomas) Price

WWU Graduate School Collection

Thermococcus are an Archaeal genus of hyperthermophilic microorganisms found to be ubiquitously present in hydrothermal habitats. DNA analyses of Thermococcus isolates focusing primarily on isolates from the Juan de Fuca Ridge, Gorda Ridge, and South East Pacific Rise, were applied in order to determine the relationship between geographic distribution and relatedness. Amplified fragment length polymorphism (AFLP) analysis and multilocus sequence typing (MLST) were used to resolve genomic differences at the species and strain level in 90 isolates of Thermococcus, allowing for the detection of biogeographic patterns and evolutionary relationships within this genus. Isolates were differentiated at regional levels and into ...


Voltage-Sensitive Gating Of The Pannexin-1 Channel, Margaret A. Fuqua Jan 2013

Voltage-Sensitive Gating Of The Pannexin-1 Channel, Margaret A. Fuqua

WWU Graduate School Collection

Since its discovery just over a decade ago, Pannexin-1 (Px1) has been recognized in a number of important physiological and pathophysiological processes such as taste, inflammation, and tumor suppression. This large-pore, polymodal ion channel was initially identified as ‗voltage-dependent,‘ though there have been no precise studies concerning the gating properties of Px1 to date. Because Px1 is expressed in excitable cells, identifying voltage-gating properties of Px1 was our primary goal. Using the two-electrode voltage clamp technique, we showed for the first time that Px1 is a weakly voltage-gated channel. Depolarizing voltages up to +200 mV revealed half-maximal activation at +51 ...