Life Sciences Commons^™

Isolation, Characterization, And Genome Sequence Of The First Representative Of A Novel Class Within The Chloroflexi That Is Abundant In Some U.S. Great Basin Hot Springs And May Play Important Roles In N And C Cycling, Jeremy A. Dodsworth, Senthil K. Murugapiran, Jonathan Gevorkian, James Han, Tanja Woyke, Susan M. Lucas, Sam Pitluck, Len Pennacchio, Lynne Goodwin, Brian P. Hedlund

Undergraduate Research Opportunities Program (UROP)

A thermophilic, facultatively microaerophilic, heterotrophic bacterium, designated strain JAD2, was isolated from sediments of Great Boiling Spring (GBS), an ~80oC, circumneutral hot spring in the Great Basin GB). The strain grew anaerobically on yeast extract or peptone with an optimal growth temperature of 70-75oC. Growth was stimulated by addition of 0.01 atm O2 to the culture vessel headspace, but was inhibited by higher concentrations (0.2 atm). Cells of JAD2 formed non-motile filaments ranging from 10 to >300 μm in length, which typically decreased in length during stationary phase. 16S rRNA gene-targeted pyrotag sequencing and clone library data suggest that close …

Magnetosome Genes In The Gammaproteobacterium Strain Bw-2, Lucero Rivera, Denis Trubitsyn, Dennis A. Bazylinski

Undergraduate Research Opportunities Program (UROP)

Magnetotactic bacteria (MTB) biomineralize intracellular nanometer-sized, magnetic crystals surrounded by a lipid bilayer membrane known as magnetosomes. These crystals, which consist of magnetite (Fe3O4) or greigite (Fe3S4), causes the cell to align along the geomagnetic field lines as they swim, a phenomenon known as magnetotaxis. Strain BW-2 is a magnetite-producing magnetotactic bacterium isolated from Badwater Basin, Death Valley National Park (California) and is one of only two species of MTB that are known to phylogenetically belong to the Gammaproteobacteria class of the Proteobacteria phylum. The biomineralization of magnetite in magnetotactic bacteria is mediated by a series of genes that include …

A Spatial And Temporal Analysis Of Microbial Communities In Great Boiling Spring, Nevada, U.S.A., Jessica K. Guy, Joseph P. Peacock, Jeremy A. Dodsworth, Tanja Woyke, Tijana G. Del Rio, Brian P. Hedlund

Undergraduate Research Opportunities Program (UROP)

Great Boiling Spring (GBS) is a large, circumneutral, long residence time geothermal spring in the US Great Basin. Twelve samples were taken from four different sediment sites and the planktonic community in the bulk water of GBS on up to four different dates. Microbial community composition and diversity was assessed by using a barcoded, improved universal primer set targeting the V8 portion of the 16S rRNA gene and PCR. Over 200,000 products were sequenced using the Roche 454 GS FLX Titanium System. Sediment and planktonic microbial communities were distinct with very little overlap, regardless of the sampling location or temperature. …

Biological Effects On Serpentinite Weathering, Mary H. Evert, Julie Baumeister, Elisabeth Hausrath

Undergraduate Research Opportunities Program (UROP)

Serpentinites, perhaps more than any other rock type, control the composition and evolution of the development of the surrounding ecosystems. The bulk chemistry of serpentinite rocks, high in Mg and trace elements, and low in nutrients such as Ca, K, P, and N, causes an extreme and stressful environment for ecosystems. However, the role that those serpentine ecosystems play in development of serpentine soils has not been examined.

Due to the unusual chemistry of serpentine soils, serpentine ecosystems have deeper and better-developed root systems than other ecosystems. The rhizosphere of serpentine systems, documented to produce abundant organic acids and siderophores, …

The Use Of Chloramines To Eradicate Quagga Mussel Larvae, Trea Lacroix, Kumud Acharya

Undergraduate Research Opportunities Program (UROP)

Quagga Mussels, Dressenia bugensis, are a growing problem in the western United States, particularly in their ability to infest underwater infrastructures and clog water intake pipes and screens of power and treatment plants. Chlorine has been found to be the most effective chemical to get rid of veligers (planktonic larval form of quagga mussels) in the pipes. However, chlorine leaves a residue called trihalomethane, which is a carcinogen at higher concentrations. The purpose of this project is to test the effectiveness of an alternate chemical, chloramines (chlorine and ammonia), which leaves behind little to no residual trihalomethane. Upon experimentation with …

Evaluating Species Responses To Climate Change Using Ecological Niche Modeling And Genetic Data, Jeanette Perry

Undergraduate Research Opportunities Program (UROP)

The current and projected future warming trends together with degradation of habitats throughout much of the Great Basin and Columbian Plateau represent real threats to many species occupying these regions. If we can determine the impacts of past climatic changes on the distribution of species, we can obtain a better understanding of the future impacts of projected climatic trends on many species in these regions. My results with the Great Basin Pocket Mouse (Perognathus parvus) may be relevant to conservation ecologists and resource managers attempting to protect several Endangered Species Act candidates, such as the pygmy cottontail (Brachylagus idahoensis). I …

Effects Of Climate Change On The Viability Of The Devils Hole Pupfish, Matthew Heuton, Stanley D. Hillyard, Frank Van Breukelen

Undergraduate Research Opportunities Program (UROP)

Devils hole is an unusual, cavernous, aquifer-fed its ideal temperature range. spring in Death Valley National Park. It is the only home to a critically endangered species, Cyprinidon diabolis, a.k.a. The Devils Hole Pupfish. C. diabolis allows us a unique look at the impact of climate change on a species that has no gene flow and no possibility of escape from its current habitat. Climate change affects ectotherms (cold-blooded animals) tremendously since their body temperature is subject to changes in the temperature of their environment. In the case of C. diabolis, they are subject to high temperatures year round, around …

Community Classification And Distribution Patterns Of Freshwater Mussels Of Strawberry River, Arkansas, Sujata Poudel, David E. Tenenbaum Ph.D, John L. Harris, Alan D. Christian Ph.D

Interdisciplinary Perspectives: a Graduate Student Research Showcase

The purpose of this study is to determine if there are distinct communities of freshwater mussels in the Strawberry River, Arkansas, and if environmental variables influenced these communities. The Strawberry River watershed is located in the Ozark Mountains in northcentral Arkansas. Based on previous studies of interior highland mussels, we expected distinct low, mid, and high order stream mussel communities. Mussels were surveyed from headwaters to mouth and resulted in 38 species from 57 sites. Environmental variables of land cover, geology, soiltype, and drainage area were calculated at local and subwatershed scale using GIS. Mussel presence/absence and environmental variables were …

Oral Presentation: Plant Genes And Drought Tolerance, Norris Lam

Festival of Communities: UG Symposium (Posters)

Research has shown that a gene from C3 xerophyte Larrea tridentata (creosote bush), LtWRKY21, is involved in pathways governing creosote bush’s high tolerance to environmental stress. By understanding the way in which creosote bush adapts to drought, crop plants can be engineered to be more drought tolerant during times of imminent global climate change. To study the underlying mechanisms of creosote bush drought response, the LtWRKY21 gene was mobilized into the model organism Arabidopsis thaliana. Chlorophyll degradation, cellular electrolyte leakage, and water content in leaves will serve as indicators of drought tolerance in LtWRKY21-transgenic A. thaliana after treatment in chemically …

Has Recent Climate Change Caused A Genetic Bottleneck In A Sierra Nevada Population Of The Bushy-Tailed Woodrat?, Mitchell Gritts, Angela D. Hornsby, Majorie D. Matocq

Festival of Communities: UG Symposium (Posters)

Many montane species respond to climate change by shifting their range upslope as temperatures at lower elevations increase. An elevation range shift causes a range contraction that may result in a population bottleneck. Joseph Grinnell surveyed the fauna along the Yosemite transect from 1914 to 1920. In 2003 Craig Moritz and his colleagues began to resurvey the Yosemite transect to assess the faunal change during a century of climate change. The bushy-tailed woodrat suffered severe range contraction and population bottleneck between the two surveys. I will use evolutionary models to determine if the population has suffered a genetic bottleneck.

Stationary Phase Mutagenesis In Bacillus Subtilisis Independent Of Genome Replication, Mark Upchurch, Holly Martin, Eduardo Robleto

Festival of Communities: UG Symposium (Posters)

Stationary phase mutagenesis is defined as cellular mechanisms that produce genetic diversity in cells experiencing conditions of stress. These processes are associated with many biological phenomena, including those that produce the formation of cancers in animal cells and other degenerative diseases. Also, these mechanisms are associated with the accumulation of beneficial mutations in bacteria, but follow stochastic processes and are controlled by genetic factors. The current models explaining the generation of stress-induced mutations are predicated on the formation of DNA replication intermediates that are formed during the repair of damaged DNA or during DNA replication and transcription encounters. Here we …

Does Thermal Stress Cause Females Of The Plant Bryum Argenteum To Manipulate The Sex Ratios Of Their Offspring?, Elisha Rhodes, Lloyd Stark

Festival of Communities: UG Symposium (Posters)

About half of all moss taxa exhibit female-biased sex ratios, and bryophyte male rarity remains largely unexplained. One possible explanation is differential stress tolerance of spores due to maternal sporophyte manipulation during stress. To test this hypothesis, sporophytes of the species Bryum argenteum were subjected to thermal stress and observed for growth abnormalities and sporophyte abortions. Data display a correlation between increased temperature and increased sporophyte abortions as well as increased time to complete meiosis, possibly indicating decreased fitness. Continued global warming may create more stressful environments for sporophytes resulting in the elimination of males from local populations.