Genetics and Genomics Commons^™

Distribution And Ecological Function Of Pacific Lamprey In The San Luis Obispo Creek Watershed, Parker Kalan

Master's Theses

Pacific lamprey (Entosphenus tridentatus) is an endemic species to coastal watersheds along the Pacific Rim in North America and Asia. The species' geographic distribution is retracting and has not been mapped precisely, and the ability for the species to provide ecosystem services, such as water filtration, for supporting watershed management has not been tested. The San Luis Obispo Creek watershed, California, USA is at the southern end of Pacific lamprey’s retracting distribution, and the San Luis Obispo watershed is impacted by degraded water quality, making investigation of Pacific lamprey in the San Luis Obispo Creek watershed of direct …

Young Forests And Fire: Using Lidar–Imagery Fusion To Explore Fuels And Burn Severity In A Subalpine Forest Reburn, Kristin H. Braziunas, Diane C. Abendroth, Monica G. Turner

Aspen Bibliography

Anticipating fire behavior as climate change and fire activity accelerate is an increasingly pressing management challenge in fire-prone landscapes. In subalpine forests adapted to infrequent, stand-replacing fire, self-limitation of burn severity in short-interval fire is incompletely understood. Spatially explicit fuels data can support assessments of landscape-scale fire risk and fuel feedbacks on burn severity. For a ~1450-km² largely forested landscape in the US Northern Rocky Mountains, we used airborne lidar and imagery to predict and map canopy and surface fuels. In a fire that burned mature (>125-year-old) and also reburned young (~30-year-old) subalpine forest, we then asked: (1) …

Gene Drives And The Consequences Of Over-Suppression, Cole Butler

Biology and Medicine Through Mathematics Conference

No abstract provided.

Elevated Substitution Rates Among Wolbachia-Infected Mosquito Species Results In Apparent Phylogenetic Discordance., James E. Russell, Michael Saum, Rebekah Williams

Georgia Journal of Science

As one of the most widely distributed bacterial cytoplasmic symbionts on earth, Wolbachia pipientis Hertig serves as a model organism for the understanding of host-symbiont interactions. Many mosquito species are infected with Wolbachia strains that induce a form of reproductive manipulation called cytoplasmic incompatibility, in which infected females gain a reproductive advantage over uninfected females in mixed infection populations. The selective advantage of cytoplasmic incompatibility often results in a population sweep of Wolbachia and co-transmitted mitochondrial genomes. Mitochondrial evolution and phylogenetic inferences drawn from mitochondrial gene sequences are thus potentially compromised by reproductive manipulating symbionts, like Wolbachia. Our initial …

Du Undergraduate Showcase: Research, Scholarship, And Creative Works: Abstracts, Emma Aggeler, Elena Arroway, Daisy T. Booker, Justin Bravo, Kyle Bucholtz, Megan Burnham, Nicole Choi, Spencer Cockerell, Rosie Contino, Jackson Garske, Kaitlyn Glover, Caroline Hamilton, Haley Hartmann, Madalyne Heiken, Colin Holter, Leah Huzjak, Alyssa Jeng, Cole Jernigan, Chad Kashiwa, Adelaide Kerenick, Emily King, Abigail Langeberg, Maddie Leake, Meredith Lemons, Alec Mackay, Greer Mckinley, Ori Miller, Guy Milliman, Katherine Miromonti, Audrey Mitchell, Lauren Moak, Megan Morrell, Gelella Nebiyu, Zdenek Otruba, Toni V. Panzera, Kassidy Patarino, Sneha Patil, Alexandra Penney, Kevin Persky, Caitlin Pham, Gabriela Recinos, Mary Ringgenberg, Chase Routt, Olivia Schneider, Roman Shrestha, Arlo Simmerman, Alec Smith, Tessa Smith, Nhi-Lac Thai, Kyle Thurmann, Casey Tindall, Amelia Trembath, Maria Trubetskaya, Zachary Vangelisti, Peter Vo, Abby Walker, David Winter, Grayden Wolfe, Leah York

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Showcase.

A Review Of Current Methods In Avian Dietary Analysis And Their Integrated Application To Characterize The Trophic Niche Of Louisiana Waterthrush (Parkesia Motacilla)., Brandon Hoenig

Electronic Theses and Dissertations

Characterizing a species’ dietary composition presents an avenue to understand many facets of its ecological niche and can provide essential information for the species’ long-term conservation. To date, the vast majority of diet studies have relied on direct identification of prey during foraging observations or from diet samples to characterize the dietary habits of birds. However, advancements in laboratory-based approaches have revolutionized the field of trophic ecology by allowing researchers to indirectly infer dietary habits with higher resolution across greater time scales. Here, I apply two of these laboratory-based techniques, namely DNA metabarcoding and stable isotope analysis, to characterize the …

Analysis Of Water Quality And Fish Communities Of Crooked Creek, Tributary To The Allegheny River In Southwestern Pennsylvania, Katherine Stupar

Electronic Theses and Dissertations

Crooked Creek is a tributary of the Allegheny River with a drainage area of 292 square miles. It has been historically affected by mine drainage pollution. Extensive cleanup and monitoring efforts by the Commonwealth of Pennsylvania and the U.S. Army Corps of Engineers (USACE) have taken place over the last four decades. Unconventional oil extraction, or fracking, presents an emerging threat to the water quality of this stream and the health of its fish communities. Here we perform an analysis of the Crooked Creek watershed utilizing backpack electrofishing, eDNA metabarcoding, and various methods of water quality analysis. Seven sites on …

Investigation Of Dna Variability And Phylogenetic Relationships Of Perlesta (Plecoptera: Perlidae) In Mississippi, James C. Valentine, Mac H. Alford

Master's Theses

The genus Perlesta Banks, 1906 (Plecoptera: Perlidae) consists of 35 species, 33 native to the United States and Canada and two native to China. For over a century these small, brown stonefly adults and freckled yellow nymphs have gone by the name of the type species of the genus, Perlesta placida, but taxonomic work in the genus since 1989 has resulted in the recognition of additional species. These species were mostly recognized and described using morphological characteristics, but two areas that are lacking include (1) linking nymphs to adults and (2) phylogenetic analysis of all species occurring in Mississippi …

Developing A Novel Place Preference Assay To Compare Drosophila Species Over Time, Martha M. Brinson

Honors Theses

Across phylogeny, integration of external factors, memory, and internal states of the organism dictate organismal behavior and mechanisms. The underlying genetic components can affect these behaviors such as in genomic changes arising from speciation. In this thesis, a new place preference assay was evaluated in the analysis and investigation of two species of Drosophila flies (D. melanogaster and D. simulans) to measure similarities and differences and their attraction to two different food substrates. Sleep and circadian measurements were also recorded during experimentation. The Drosophila Activity Monitor 5M (DAM5M) System and Sleep Circadian Analysis MATLAB Program (SCAMP) analysis were …

A Genetic Evaluation Of The Impacts Of Dams On Sauger Movement Patterns In The Arkansas River, Emily R. Jonagan

ATU Theses and Dissertations 2021 - Present

Decreased habitat connectivity as a result of damming can lead to genetic isolation in fish communities, especially in highly migratory species. Sauger Sander canadensis is a migratory freshwater species native to the Arkansas River. Sauger are highly sought after by anglers during their annual spawning migration in late winter. In order to investigate the impacts Arkansas River dams on Sauger populations, fin clips were collected in the winters of 2019, 2020, and 2021 below eight dams in the McClellan-Kerr Arkansas River Navigational System (MKARNS). Fin clips were also collected from two reservoirs in Kansas to serve as distinct reference populations. …

Assessing The Utility Of The Pmm And Mmc Indices Among Extant Hominoid Genera, Julie A. Strain

Theses and Dissertations

This thesis set out to incorporate extant hominoid genera into an analysis of PMM and MMC to assess utility in phylogeny and predicting known taxonomic groups. Based on previous claims, we expect PMM/pmm and MMC/mmc to perform better than M1/m1 shape and size, our baseline for success, but they do not.

Why Plasmodium Vivax And Plasmodium Falciparum Are So Different? A Tale Of Two Clades And Their Species Diversities, Ananias A. Escalante, Axl S. Cepeda, M. Andreína Pacheco

Harold W. Manter Laboratory of Parasitology: Library Materials

The global malaria burden sometimes obscures that the genus Plasmodium comprises diverse clades with lineages that independently gave origin to the extant human parasites. Indeed, the differences between the human malaria parasites were highlighted in the classical taxonomy by dividing them into two subgenera, the subgenus Plasmodium, which included all the human parasites but Plasmodium falciparum that was placed in its separate subgenus, Laverania. Here, the evolution of Plasmodium in primates will be discussed in terms of their species diversity and some of their distinct phenotypes, putative molecular adaptations, and host–parasite biocenosis. Thus, in addition to a current …

Repeated Targets Of Natural Selection During Ecological Transitions Of Fish Across Salinity Boundaries, Jonathan P. Velotta, Stephen D. Mccormick, Andrew Whitehead, Catherine S. Durso, Eric T. Schultz

EEB Articles

Ecological transitions across salinity boundaries have led to some of the most important diversification events in the animal kingdom, especially among fishes. Adaptations accompanying such transitions include changes in morphology, diet, whole-organism performance, and osmoregulatory function, which may be particularly prominent since divergent salinity regimes make opposing demands on systems that maintain ion and water balance. Research in the last decade has focused on the genetic targets underlying such adaptations, most notably by comparing populations of species that are distributed across salinity boundaries. Here, we synthesize research on the targets of natural selection using whole-genome approaches, with a particular emphasis …

Halodash: The Deep And Shallow History Of Aquatic Life's Passages Between Marine And Freshwater Habitats, Eric T. Schultz, Lisa Park Boush

EEB Articles

This series of papers highlights research into how biological exchanges between salty and freshwater habitats have transformed the biosphere. Life in the ocean and in freshwaters have long been intertwined; multiple major branches of the tree of life originated in the oceans and then adapted to and diversified in freshwaters. Similar exchanges continue to this day, including some species that continually migrate between marine and fresh waters. The series addresses key themes of transitions, transformations, and current threats with a series of questions: When did major colonizations of fresh waters happen? What physiographic changes facilitated transitions? What organismal characteristics facilitate …

Oystershell Scale: An Invasive Threat To Aspen Conservation, Amanda M. Grady, Connor D. Crouch, Nicholas P. Wilhelmi, Richard W. Hofstetter, Kristen M. Waring

Aspen Bibliography

Aspen decline is an acute and chronic problem in Arizona, where high levels of overstory mortality and a lack of recruitment continue to be observed. Oystershell scale (Lepidosaphes ulmi; OSS), an invasive sapsucking insect, has recently become widespread in native aspen stands in the southwestern U.S., further contributing to aspen mortality. Damage is severe in lower elevation stands and within ungulate exclosures created to conserve aspen. Young recruiting aspen that are rare on the landscape incur high levels of OSS-caused mortality when infested (Fig. 1). OSS has only recently become a pest of concern in the Southwest and …

Severe Hypoxia Up-Regulates Gluconeogenesis In Daphnia, Morad C. Malek

Undergraduate Honors Theses

Hypoxia is a significant low oxygen state that has complex and diverse impacts on organisms. In aerobes, various adaptive responses to hypoxia are observed that vary depending on the level of oxygen depletion and previous adaptation, hence the continued attention to hypoxia as an important abiotic stressor. Adaptive responses to hypoxia are primarily governed by the hypoxia-inducible factors (HIFs), which activate downstream genetic pathways responsible for oxygen transport and metabolic plasticity. In aquatic habitats, oxygen availability can vary greatly over time and space. Therefore, aquatic organisms’ adaptation to hypoxia is likely pervasive, especially in genotypes originating from waterbodies prone to …

Impact Of Genetic Variation And Timescale On Diatom Salinity Stress Response, Kala M. Downey

Graduate Theses and Dissertations

Natural environments are dynamic, and organisms must sense and respond to changing conditions. One common way organisms deal with stressful environments is through gene expression changes, allowing for stress acclimation and resistance which occurs over varying time spans in different species. The recent evolutionary history of populations could greatly influence their ability to respond successfully. An evolutionary history in disturbed or fluctuating conditions could promote increased resistance or a more rapid response to these environmental stressors. To understand the impact of genotypic variation and timescales on response and acclimation to salinity changes, we have been exploiting the abilities of euryhaline …

Microbial Diversity And Community Structure In Sediments Associated With The Seagrass (Thallassia Testudinum) In Apalachicola Bay, Florida, Rahma Ahmed, Thomas Mcelroy, Troy Mutchler

Symposium of Student Scholars

Seagrass is an angiosperm which provides many ecosystem services in coastal areas, such as providing food, shelter and nurseries for many species, and decreasing the impact of waves on shorelines. A global assessment reported that 29% of known seagrass meadows are in a state of decline due to the effects of human activity. Seagrass is commonly found in shallow marine waters where they form meadows containing a microbiome that plays an important role in providing nutrients for seagrass growth, though little is known about the microorganisms within the seagrass meadow sediments. Our project collected sediments from seagrass meadows and adjacent …

Sex And Starvation Influences Latrotoxin Expression In The Brown Widow Spider, Mattie Harris

Honors College Theses

Widow spiders (genus Latrodectus) are well-known for their potent venom. Seven latrotoxin proteins constitute the main components of widow spider venom. The vertebrate specific (α-latrotoxin) and insect specific (α-latroinsectotoxin) latrotoxins have been well-characterized with respect to structure and function. Regulation of latrotoxin gene expression is not well understood but sex and feeding could be factors influencing production. In this study, I used quantitative qPCR to (1) characterize the expression patterns of both the insect and vertebrate specific latrotoxins in male and female brown widow spiders (Latrodectus geometricus) to characterize sex-biased expression and to (2) study expression patterns …

Cryptic Hybridization In The Temperate Bamboos: Is Pleioblastus Simonii A Species Of Hybrid Origin?, Morgan Brown

Theses

Japanese river bamboo (Pleioblastus simonii, ‘medake,’‘kawadake’) is an ecologically important species of temperate bamboo native to Japan. This species is widely known and historically important in Japanese rural farm life. Based on morphological data, Japanese river bamboo is classified in Pleioblastus section Medakea (Poaceae: Bambusoideae) along with five other Japanese species, which are collectively considered to represent a phylogenetically distinct lineage. However, recent studies suggest that Japanese river bamboo may have arisen as a result of previously undetected hybridization (i.e., cryptic hybridization), while also calling into question the diversity of section Medakea. The role of hybridization in natural plant populations …

Emulating Succession Of Boreal Mixedwood Forests In Alberta Using Understory Protection Harvesting, Ivan Bjelnanovic, Philip G. Comeau, Sharon Meredith, Brian Roth

Aspen Bibliography

Understory protection harvesting is a form of partial cutting that can be used in aspen (Populus tremuloides Michx.)-dominated stands that have understories of white spruce (Picea glauca (Moench) Voss). This practice involves removing 75% to 85% of the merchantable aspen while minimizing damage to the advance spruce regeneration, in addition to leaving 15% to 25% of the aspen standing to reduce potential windthrow of the spruce understory. In this paper, we summarize results from 18 stands measured 10 to 12 years after understory protection harvest. Diameter growth of spruce increased during the first five years after harvest while …

Genetic Variation Of The Mitochondrial Dna Control Region Across Plains Bison Herds In Usa And Canada, Gaimi Davies, Blake Mccann, Lee Jones, Stefano Liccioli, Maria Cecilia Penedo, Igor V. Ovtchinnikov

Biology Faculty Publications

Once numbering in the tens of millions, bison (Bison bison) have faced a broad range of challenges over the past century, including genetic impacts from the population bottleneck in the 1800s, and significant loss and fragmentation of habitat resulting in little opportunity for population growth on remaining small, geographically isolated reserves. To identify best practices for bison stewardship against this backdrop, managers must understand the genetic composition of existing conservation herds. This study characterized 14 plains bison (Bison bison bison) herds managed by the U.S. Department of Interior and Parks Canada Agency based on complete mtDNA …

Climate Effects On Black Spruce And Trembling Aspen Productivity In Natural Origin Mixed Stands, Mahadev Sharma

Aspen Bibliography

Forest managers need site productivity estimates for tree species growing in mixed stands. Models developed in the past are generally for pure stands and don’t factor in the effects of climate change on site productivity. Therefore, site index (SI) models were developed for black spruce (Picea mariana Mill. B.S.P.) and trembling aspen (Populus tremuloides Michx.) trees grown in natural origin mixed stands. For this, 186 trees (93 black spruce and trembling aspen each) were sampled from 31 even-aged natural mixed stands (sites) (3 trees/species/site) across Ontario, Canada. Stand height growth models were developed by incorporating climate variables during …

Characterization Of Streptomyces Nymphaeiformis Sp. Nov., And Its Taxonomic Relatedness To Other Polyhydroxybutyrate-Degrading Streptomycetes, Gary R. Hix, Muhammad S. Khan, Mikayla T. Miller, Elisha C. Napier, Allison L. O'Brien, Roger P. White, Stephen F. Baron Ph.D.

Biology Faculty Scholarship

A polyhydroxybutyrate (PHB)-degrading actinomycete, strain SFB5A^T, was identified as a species of Streptomyces based on its membrane fatty acid profile and the presence of LL-diaminopimelic acid in the cell wall. It formed sporulating mycelia on most agar media, but flat or wrinkled, moist colonies on trypticase soy agar. Spores were smooth, cylindrical, and borne on long, straight to flexuous chains. It produced a light brown diffusible pigment, but not melanin. Comparison of genomic digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) values indicated that strain SFB5A^T was related to Streptomyces litmocidini JCM 4394^T , Streptomyces …

Facilitation Differentially Affects Competitive Responses Of Aspen And Subalpine Fir Through Stages Of Stand Development, Rebecca Lee Molinari, Matthew F. Bekker, Benjamin D. St. Clair, Jason Bartholomew, R. Justin Derose, Stanley G. Kitchen, Samuel B. St. Clair

Aspen Bibliography

Spatial interactions between trees influence forest community succession. The objective of this study was to investigate how shifts in forest composition and proximity between tree species affect stand development over time in mixed forest systems. At six locations across the Fishlake National Forest, Utah, USA, in stands where facilitation has been documented previously, tree-ring samples were collected from aspen and subalpine fir trees. Basal area increment was calculated to characterize the effects of the proximity of overstory trees on multidecadal growth responses of aspen and subalpine fir in aspen-dominant and mixed aspen–conifer stands. Subalpine fir seedlings were established next to …

Conservation Status Assessment Of The Egg-Mimic Darter (Percidae: Etheostoma Pseudovulatum) Using A Multi-Faceted Approach, Zachary L. Wolf, John W. Johansen, Rebecca E. Blanton

Southeastern Fishes Council Proceedings

The imperiled Egg-mimic Darter (Etheostoma pseudovulatum) is a headwater-adapted fish restricted to an area less than 1000 km² in Tennessee. It is found in only six tributaries of the Duck River and the large, mainstem of this system may act as a barrier to dispersal, restricting population connectivity. The only status assessment of this species was over two decades ago; genetic diversity and the degree of population connectivity have never been evaluated. We conducted a conservation status assessment using a multi-faceted approach to better inform conservation management plans, including examining its current distribution, assessing habitat quality, estimating …

Phylogenomic Discordance Suggests Polytomies Along The Backbone Of The Large Genus Solanum, Edeline Gagnon, Rebeccca Hilgenhof, Andrés Orejuela, Angela J. Mcdonnell, Gaurav Sablok, Xavier Aubriot, Leandro Giacomin, Yuri Gouvêa, Thamyris Bragionis, João Renato Stehmann, Lynn Bohs, Steven Dodsworth, Christopher T. Martine, Péter Poczai, Sandra Knapp, Tiina Särkinen

Faculty Journal Articles

Premise of the study

Evolutionary studies require solid phylogenetic frameworks, but increased volumes of phylogenomic data have revealed incongruent topologies among gene trees in many organisms both between and within genomes. Some of these incongruences indicate polytomies that may remain impossible to resolve. Here we investigate the degree of gene-tree discordance in Solanum, one of the largest flowering plant genera that includes the cultivated potato, tomato, and eggplant, as well as 24 minor crop plants.

Methods

A densely sampled species-level phylogeny of Solanum is built using unpublished and publicly available Sanger sequences comprising 60% of all accepted species (742 spp.) …

Conservation, Comparative Genomics And Species Delimitation Of The Reindeer Lichens (Cladonia), Jordan R. Hoffman

Dissertations, Theses, and Capstone Projects

The genus Cladonia represents one of the most speciose genera of lichenized fungi, with more than 500 known species encompassing a diverse array of morphologies and habits. These lichens form keystone species in many habitats, serving a variety of ecological roles. However, despite being among of the more well studied lichens, there is much still unknown or under-studied about them. As is the case with most lichen study systems, phylogenetic study has been limited to a small number of partial loci, while adoption of next-generation sequence methods has been slow. As a consequence, there are still knowledge gaps in Cladonia …

Bottom-Up Drivers Of Future Fire Regimes In Western Boreal North America, Adrianna C. Foster, Jacquelyn K. Shuman, Brendan M. Rogers, Xanthe J. Walker, Michelle C. Mack, Laura L. Bourgeau-Chavez, Sander Veraverbeke, Scott J. Goetz

Aspen Bibliography

Forest characteristics, structure, and dynamics within the North American boreal region are heavily influenced by wildfire intensity, severity, and frequency. Increasing temperatures are likely to result in drier conditions and longer fire seasons, potentially leading to more intense and frequent fires. However, an increase in deciduous forest cover is also predicted across the region, potentially decreasing flammability. In this study, we use an individual tree-based forest model to test bottom-up (i.e. fuels) vs top-down (i.e. climate) controls on fire activity and project future forest and wildfire dynamics. The University of Virginia Forest Model Enhanced is an individual tree-based forest model …

Identifying Conifer Tree Vs. Deciduous Shrub And Tree Regeneration Trajectories In A Space-For-Time Boreal Peatland Fire Chronosequence Using Multispectral Lidar, Humaira Enayetullah, Laura Chasmer, Christopher Hopkinson, Dan Thompson, Danielle Cobbaert

Aspen Bibliography

Wildland fires and anthropogenic disturbances can cause changes in vegetation species composition and structure in boreal peatlands. These could potentially alter regeneration trajectories following severe fire or through cumulative impacts of climate-mediated drying, fire, and/or anthropogenic disturbance. We used lidar-derived point cloud metrics, and site-specific locational attributes to assess trajectories of post-disturbance vegetation regeneration in boreal peatlands south of Fort McMurray, Alberta, Canada using a space-for-time-chronosequence. The objectives were to (a) develop methods to identify conifer trees vs. deciduous shrubs and trees using multi-spectral lidar data, (b) quantify the proportional coverage of shrubs and trees to determine environmental conditions driving …