Biology Commons^™

An Exploration Of Plasticity In Apocynum Cannabinum, Mia Moore 28, Rose Keith

Annual Student Research Poster Session

Hemp Dogbane (Apocynum Cannabinum) is a perennial plant native to the United States known for being extremely plastic, meaning its morphological traits adapt to its environment. This study explores how dogbane adapts to microgeographic variance and how its morphological traits are influenced by its genetics vs. the environment. We conducted various experiments over the summer. The first was a large census at the beginning of the summer where we measured several morphological traits of dogbane from the quarry bottom of the DePauw Nature Park (DNP) and various other locations in or adjacent to the DNP. We repeated this census at …

Comparative Analysis Of Bacterial Recbcd And Sbcc-Sbcd Systems And The Yeast Mre11-Rad50 Complex During Dna Replication, Tannos Seyedjavadi

Dissertations and Theses

Accurate completion of DNA replication when forks converge is essential for genome stability. In Escherichia coli, several proteins have been identified including RecG, ExoI, RecBCD, and SbcCD, that contribute to completing replication, and loss of these factors causes genetic instability. Eukaryotes encode proteins with homology to several E. coli completion enzymes. Mre11–Rad50 complex is structurally and functionally conserved with bacterial SbcCD, and Rrm3 shares homologous motifs with bacterial RecBCD. These proteins are often described as being involved in homologous double strand break repair. Whether they are also conserved and play a similar role as their E. coli counterparts in …

Bees In The Trap: Leveraging Bumble Bee (Hymenoptera: Apidae: Bombus) Bycatch For Ecological And Genetic Insights, Tori L. Strausser

All Graduate Theses and Dissertations, Fall 2023 to Present

Managers rely on insect monitoring traps to detect insect pests that harm crops and protect food and other agricultural production. However, these traps also capture non-target insects, including bumble bees, raising concerns about whether repeated trapping could harm pollinator populations. This thesis explores whether bees caught as non-targets, also called bycatch, in routine pest monitoring traps can be used to better understand bumble bee populations, and whether traps pose risks to their long-term persistence. Using bumble bees collected from pest surveillance traps placed in crop fields across Utah, this research examined seasonal patterns in body size, timing of capture, and …

Using Temporal Genomic Data To Uncover Patterns Of Genetic Diversity And Signatures Of Selection For Management Of A Threatened Minnow Species, Erika A. Dunn

Biology ETDs

The Little Colorado River (LCR) spinedace persists only in three isolated watersheds within the LCR Basin in Arizona. This imperiled minnow faces ongoing pressure from habitat alteration, climatic shifts, and invasive non-native predators. Over the past two decades, managers have translocated spinedace within watersheds to increase abundance and expand habitat occupancy. We sequenced a reference genome and analyzed single nucleotide polymorphisms (SNPs) from 475 individuals over their geographic range. DNA samples were obtained from a previous study in the mid-1990s and compared with samples from 2024 and 2025, allowing us to track genetic diversity, effective population size, population structure, and …

Exploring Biogeographical Ancestry Inference Of New York Residents Using A 45 Indel Panel, Amanda Martinez

Student Theses

Biogeographical ancestry (BGA) inference is an important tool in forensic science, providing supplemental information when comparison/reference DNA is not available for traditional DNA analyses. Insertion/deletion polymorphisms (INDELs) have been used in the last decade as ancestry-informative markers (AIMs) for BGA inference because they can be easily adapted to forensic-type samples and are determined using low cost and easy processing methods. Limited research has attempted to estimate ancestry and admixture in United States (U.S.) populations. This study evaluated the effectiveness of a 45- and 21- INDEL panel to measure population admixture proportions of four different origins (African, European, East Asian and …

Investigating The Taxonomic Uncertainties Of Potentilla Rupincola, Natalie Elizabeth Hieber

Master's Theses

Landscape stewardship is an integral role for land managers that becomes more important when rare or endangered species occur within managed areas. Conservation across the landscape is a primary concern for land managers, but resources allocated for conservation can be limited due to many competing goals. Taxonomic uncertainty surrounding rare and endangered taxa, particularly plant taxa, that have historically been classified solely using morphological features further complicates conservation planning. One such taxon is Potentilla rupincola, a rare plant endemic to the eastern Rocky Mountains in Colorado. For over a century, botanists have debated whether P. rupincola is a distinct species …

Using The Flexon Approach To Rnai To Identify Essential Genes That Affect Gonadal Development In C. Elegans, Joyce S. Lefevers

Undergraduate Theses

To elucidate the molecular role of essential genes in the gonadal development of Caenorhabditis elegans (C. elegans) it is necessary to utilize specialized molecular techniques such that the phenotypic effects of gene knockdown can be studied while the viability of the organism is preserved. Shaffer and Greenwald (2022) developed the floxed exon (flexon), a tool that improves upon previous approaches to spatiotemporal control of gene expression. The flexon subunit is made up of an artificial exon with a stop cassette flanked by artificial introns which, when inserted into a gene of interest, prevents the expression of that gene. …

Paternal Effects Without Paternity? Testing Non-Genetic Male Influence On Offspring Size And Brood Size In A Gynogenetic Vertebrate, The Amazon Molly (Poecilia Formosa), Ulrike Scherer, Sean Ehlman, David Bierbach, Jens Krause, Max Wolf

Faculty Publications

Paternal effects, i.e., effects of fathers on the phenotype of their offspring that are not mediated by the transmission of alleles, are increasingly recognized as a potentially significant source of phenotypic variation across taxa – even in the absence of paternal care. Gynogenetic systems, which rely on sperm to trigger embryogenesis without incorporating male genetic material, provide a powerful way to experimentally isolate paternal effects from effects caused by the integration of male genetic material. Up to now, however, paternal effects remain largely unexplored in these systems. Here, we tested for non-genetic paternal effects in the gynogenetic Amazon molly ( …

A Trajectory Of Zostera Marina (Eelgrass) Ecosystem Recovery: Pre- And Post-Hurricane Sandy Degradation In Barnegat Bay, New Jersey, Edgar A. Medina

Theses, Dissertations and Culminating Projects

Hurricane Sandy struck Barnegat Bay, New Jersey in 2012 and obliterated the benthic marine ecosystem with extensive damage to Zostera marina meadows. Previous genetic assessments of Barnegat Bay Z. marina in 2008 revealed low heterozygosity and low connectivity between populations. The great disruption caused by Hurricane Sandy motivated us to investigate the long-term effects of the storm on the genetic condition of the eelgrass populations in the year 2021. The investigation revealed improvements in heterozygosity, inbreeding, and connectivity. These findings drove us to investigate the genetics of Barnegat Bay eelgrass populations in the intervening years of 2013 and 2017 with …

Species Boundaries Of The Rare Menzies’ Wallflower (Brassicaceae: Erysimum Menziesii), An Endemic Of The Northern California Coast, Cameron M. Jones

Cal Poly Humboldt theses and projects

Morphological similarity among geographically isolated populations can obscure deep evolutionary divergence, especially when convergent evolution under similar environmental conditions yields comparable phenotypes across independent lineages. Such cryptic diversity is likely underestimated in hotspots like the California Floristic Province (CFP), a global biodiversity hotspot, defined by its Mediterranean-like climate and encompassing most of California, southwestern Oregon, and northwest Baja California. The CFP is home to a disproportionate number of narrow endemics whose origins and evolutionary relationships remain poorly understood. Here, I investigate the evolutionary origins of Erysimum menziesii (Brassicaceae), a federally endangered California coastal dune endemic whose fragmented distribution has led …

Genetic Characterization And High-Resolution Total Mrna Sequencing Of The Millipede Cherokia Georgiana Bollman, 1889, Elena Cruz

Biology Theses

There are approximately 12,000 described species within the class Diplopoda. Only six species, falling within four of sixteen orders, have fully sequenced genomes. No whole genomes are available for incredibly diverse families like Xystodesmidae. Many interesting characteristics in this group are poorly defined at the genetic level, such as the production of a defensive hydrogen cyanide secretion and UV fluorescence in the order Polydesmida. Here, we present a genetic characterization of the polydesmid millipede Cherokia georgiana Bollman, 1889. We include tissue-specific sequencing metrics, alignment and assembly of mitochondrial DNA consensus sequence according to tissue type, and phylogenetic tree construction using …

Population Genomic Assessment Of The Endangered Cumberland Darter (Etheostoma Susanae), Hilary Canada

Student Theses and Dissertations

The Cumberland Darter (Etheostoma susanae) is an endangered species of freshwater fish endemic to the tributaries of the Cumberland River above the Cumberland Falls in Kentucky and Tennessee. Once recognized as a subspecies of Johnny Dater (E. nigrum), E. susanae was elevated to species level based on morphological and mtDNA variation. Habitat degradation and modification is a primary concern for the species with its preference for slow-flow streams. Fragmented populations increase the risk of disrupting historic gene flow between tributaries which could potentially result in genetically distinct populations. In 2011, E. susanae was listed under the Endangered Species Act by …

Understanding The Effects Of Genetic Variation On Maize And Pennycress Root System Architectures And Their Interaction With Nitrogen, Alexander Euway Liu

Arts & Sciences Graduate Student Theses and Dissertations

Roots are a critical yet hidden part of plants, providing physical support and access to resources such as nutrients and water. The development of a plant’s root system across time and space is referred to as root system architecture, which influences the effectiveness of resource capture. In modern agriculture, applications of nitrogen fertilizers are critical to maintain high yield. However, up to 70% of applied nitrogen is not utilized by the plant and escapes into waterways and the atmosphere, causing environmental harm. Efficient nitrogen uptake is limited by the ability of the plant to access and absorb nitrogen through its …

The Island Biogeography Of Mangrove-Dwelling Vertebrates: Isolation, Specialisation, And Extinction, Jian Xiong David Tan

Biology ETDs

Mangroves are highly dynamic ecosystems that are widely distributed across the coastlines of the tropics and subtropics. Despite their low plant diversity, mangroves host a disproportionately high number of terrestrial vertebrate taxa. However, mangrove specialists — taxa that only occur in mangrove habitats — exhibit a global distribution that is incongruous with the broader background distribution patterns of mangrove-associated fauna, exhibiting higher diversity in Australia and Southeast Asia. This dissertation therefore aims to assess how the diversity and distribution of mangrove specialist fauna may have been shaped by the historical biogeography of mangroves, and the effects of mangrove specialisation on …

Genetic Structuring Of The Ozark Pocket Gopher (Geomys Bursarius Ozarkensis) And Coevolution With Its Geomydoecus Ectoparasites, Monica Raquel Reusche

Student Theses and Dissertations

The Ozark pocket gopher Geomys bursarius ozarkensis is a highly isolated and restricted subspecies of the plains pocket gopher endemic to Izard Co., Arkansas. This isolation may have impacts genetically and may have caused speciation of their chewing louse. First, I updated the distribution and confirmed occupation at 46 previously documented and 91 additional sites, a 34% increase in areal range. Next, I evaluated natal dispersal which was rare (9.1%) and occurred over shorter distances (≤ 63 m) than for other gopher species. Analysis of single nucleotide polymorphisms from contemporary populations and museum specimens indicated a high genetic structure among …

Comparative Methylation Analyses Across Juglans Species To Investigate Epigenetic Contributions To Fungal Resistance, Keertana Chagari

Honors Scholar Theses

Juglans cinerea (butternut) is a critically threatened North American tree species experiencing severe declines due to the fungal pathogen Ophiognomonia clavigignentijuglandacearum. In contrast, its Asian relative, Juglans ailantifolia (Japanese walnut), shows natural resistance. To investigate the genomic and epigenetic factors underlying this difference, we constructed and analyzed high-quality, chromosome-level genome assemblies for both species from long-read sequencing data (J. ailantifolia: 527Mb; J. cinerea: 586Mb), focusing on transposable element (TE) content, DNA methylation patterns, and regulation of pathogen resistance genes (PRGs).

Repeat analysis revealed that J. cinerea has a slightly higher overall transposable element (TE) content, with …

Ethical Concerns And Implications Of Expanded Carrier Screening, Emily Andres

Undergraduate Honors Capstone Projects

The rapid evolution in the field of genetics is often met with uncertainty and skepticism. With the advancements in genetic technologies, expanded carrier screening (ECS) has emerged as a powerful tool in reproductive medicine. Traditionally, carrier screening was provided less broadly, often relying on ethnic-based approaches. However, further advancements have deemed this practice no longer equitable or widely accepted. While ECS provides prospective parents with insight into their genetic risk and may prevent severe genetic conditions, it also raises serious ethical questions for many. These concerns span medical, political, and societal facets including medicalization, defining severity, abortion, legislation, insurability, the …

Crispr-Induced Mutagenesis Of Arabidopsis Thaliana Gene Apetala3, Hazel Frans, Tara Phelps-Durr

SACAD: Scholarly Activities

This project aims to create CRISPR-CAS9 mutations in the APETELA3 (AP3) gene of the model plant Arabidopsis thaliana. AP3 is a class B gene critical to the petal and stamen development of Arabidopsis flowers. AP3 is defined in a MADS domain, which binds directly to DNA and may be responsible for the expression of the CaRG-box genes. AP3 works in conjunction with PISTILLATA (PI), AGAMOUS (AG), APETALA1 (AP1), and SEPALLATA (SEP) genes to specify the development in the second and third whorls of the flower. While several alleles of AP3 already exist, these alleles are strong alleles that knockout gene …

A Study To Identify The Causal Rare Genetic Variants In Primary Open And Closed Angle Glaucoma, Pseudoexfoliation Syndrome, And Associated Glaucoma, Suganya K

Theses and Dissertations

BACKGROUND: Glaucoma is the second most common cause of blindness globally typically diagnosed with a triad of clinical symptoms of increased intraocular pressure (IOP) with associated optic disc, optic nerve head (ONH) changes, and visual field defects. Genetic and environmental factors are some of the strong aetiology factors for glaucoma and identification of these factors has a potential implication in the management of the disease and its outcome. There is a paradigm shift towards understanding the genetics of glaucoma, wherein the variants in the nuclear, mitochondrial genome and other regulatory regions are being identified as contributing risk factors.

METHODOLOGY AND …

What Are The Genetic Influences Of Alcohol Sensitivity And Alcohol Metabolism? A Narrative Review Of Human Studies, Erwin Murray, Karen G. Chartier Phd, Msw

UROP Posters

Background: Alcohol sensitivity and alcohol metabolism are two phenotypes associated with alcohol use disorder (AUD) influenced by genetics. This narrative review aims to answer “What are the genetic influences of alcohol sensitivity and alcohol metabolism?” to gain a better understanding of the genetic aspects of AUD.

Methods: A database search was performed in PubMed. Empirical human genetic studies published between 2009 and 2025 that focused on alcohol sensitivity (measured by the Self-Rating of the Effects of Alcohol scale) or alcohol-metabolizing genes were eligible for review. Studies were screened to determine inclusion for the current review.

Findings: Fifteen …

Diversification Of Avifauna In The Darién Highland Region: Ecological Niche Modeling, Phylogeography And Morphology To Explore Speciation In The Montane Species Myadestes Coloratus, Chlorospingus Tacarcunae And Margarornis Bellulus., Jorge L. Garzon Vasquez Mrs

Theses and Dissertations

Montane regions in the Neotropics are hotspots of endemism and biodiversity, yet their species are especially vulnerable to the impacts of climate change and geographic isolation. This thesis investigates the evolutionary and ecological dynamics of three bird species endemic to the Darién Highlands of eastern Panama: Myadestes coloratus, Chlorospingus tacarcunae, and Margarornis bellulus. Through an integrative approach combining ecological niche modeling, morphometric analysis, and genomic data from ultraconserved elements (UCEs) and mitochondrial DNA, the study explores the historical biogeography, current distribution patterns, population structure, and phenotypic differentiation of these montane taxa. Ecological niche models revealed that suitable habitat …

Determining The Genetic Population Structure Of The Endangered Scirpus Ancistrochaetus Using Genomic Sequences, Kayci Johnson

Browse all Theses and Dissertations

Wetlands are biodiverse ecosystems across the world, and they are being lost at alarming rates due to fragmentation and anthropogenic stressors. Many wetland plants are endangered or threatened due to wetland decreasing numbers. Scirpus ancistrochaetus is an endangered wetland species in the northeastern United States. It is most commonly found in lowlands and forested ecosystems. In this study, I used 105 polymorphic loci obtained from double-digest restriction site associated DNA sequencing (ddRAD-seq), a conservation genetics tool, to determine conservation units, gene flow, kinship, and isolation-by-distance patterns. Discrete populations were identified in New England and the southern part of the species’ …

Monitoring The Seasonal Presence Of The Blue Shiner, Cyprinella Caerulea, In Little River Canyon National Preserve Using Environmental Dna, Deanna Meadows

Theses

The study of environmental DNA (eDNA) has provided researchers with a more accessible and sensitive way to identify the presence of specific species compared to traditional monitoring methods. eDNA enables species detection by analyzing environmental samples such as water or soil, which contain genetic material shed by organisms in a given area. Research indicates that eDNA techniques have become a valuable method for monitoring threatened and invasive species, proving particularly reliable for detecting aquatic species compared to traditional techniques. Quantitative PCR (qPCR) has been used in numerous eDNA studies, as it provides for greater accuracy than conventional PCR. Cyprinella …

Exploring Genetic Elements Related To The Co-Occurrence Of Crohn’S Disease And Rheumatoid Arthritis, Vamsi Korisapati, Karam Asad, Andrew T. Ozga

Mako: NSU Undergraduate Student Journal

Crohn’s disease (CD) is a rare inflammatory bowel disease that negatively impacts the lining of the digestive tract, while Rheumatoid Arthritis (RA) is an autoimmune disorder wherein the body attacks healthy cells, also causing inflammation. The primary cause of inflammation in both diseases is an overactive immune response, but patients who are diagnosed with RA are typically prescribed nonsteroidal anti-inflammatory drugs, which is not a suggested method for treating CD. Here we do a literature survey through PubMed to uncover genetic variants common to both diseases and highlighted four shared genes: HLA-DRB1, NOD2, CARD9, and CXCL10. We then examined these …

Understanding The Relationship Between Genetic And Epigenetic Variation At A Species And Individual Level, Kara Quaid

Arts & Sciences Graduate Student Theses and Dissertations

Genetic sequences and epigenetic features work together to regulate gene expression, which can vary across species, individuals, and cell-types. Understanding this relationship between genetics and epigenetics is a key step to revealing the connection between genotype and phenotype on a systematic, genome-wide level. The first chapter of my thesis outlines the ways genetic variation and epigenetic variation may interact to shape gene regulation across scales, as well as how we can question it further. One of the most studied mechanisms is genetic variation that has a direct impact on epigenetic variation. At the species level, it is documented that species-specific …

Feather Mites Through Genomic And Ecological Lenses: Host Specificity And Symbiosis At Multiple Levels Of Organization, Alix Elizabeth Matthews

Student Theses and Dissertations

Symbionts, or organisms that form close and persistent associations with hosts, are ubiquitous across the tree of life, and symbioses are among the most common interspecific interactions in the natural world. Symbionts play a fundamental ecological and evolutionary role across multiple levels of biological organization – from individuals to ecosystems – and can have strong effects on global biodiversity. However, many aspects of these relationships are poorly understood including symbiont genetic diversity (inter- and intraspecific), host specificity, and the mechanisms underlying their functional nature or any context-dependent patterns. This dissertation uses a model symbiosis between permanent, obligate, ectosymbiotic vane-dwelling feather …

Mutating Lysine 336 In Msh6 Does Not Appear To Affect Dna Mismatch Repair In Saccharomyces Cerevisiae, Anthony Thompson, Daniel Reese, Noa Bennafield, Kalila Daveron, Christopher Bolden, Joanna E. Haye-Bertolozzi

XULAneXUS

Defects in the DNA mismatch repair process results in the accumulation of mutations and disease. Mutations in MSH6 and MSH2, encoding for the subunits of the MutSα complex, are often responsible for Constitutional Mismatch Repair Deficiency (CMMRD) and Lynch Syndrome (LS), respectively. This work focused on DNA mismatch repair through analysis of the MSH6 missense variant msh6-K336T. The mutation examined in this study is msh6-K336T in Saccharomyces cerevisiae, which is equivalent to msh6-K431T in humans. The mutation results in the replacement of lysine with threonine, an amino acid with different properties. It was therefore hypothesized that the mutation …

The Tissue-Specific Role Of Smn-1 In C. Elegans, Lindsey Philips

Biological Sciences Theses and Dissertations

Spinal muscular atrophy (SMA) is an autosomal recessive disease that results from mutations in the Survival Motor Neuron (SMN-1) gene. Although SMN is a ubiquitously expressed protein that acts as an RNA-binding protein (RBP), SMA is characterized by the selective degeneration of motor neurons of the lower spinal cord. Despite a clear understanding of the genetic causes underlying SMA, the mechanisms associated with low SMN levels to disease pathogenesis remains unclear. Here, we investigate the role SMN-1 has in different tissues to begin understanding possible mechanisms. This project has three aims that has guided our experiments. The first aim is …

Omani Camels From A Cultural And Genomics Perspective, Al Muatasim Al Zadjali

Electronic Theses and Dissertations

The Dromedarian camel, Camelus dromedarius, is native to the Arabian Peninsula, including the Sultanate of Oman. These camels are used for food, milk, as well as show and racing competitions. Despite their economic and cultural importance research on camels in Oman is limited. The goal of this study was to examine their genomic variation, relationship with camels in other parts of the Arabian Peninsula, and to determine if selective breeding has led to the establishment of distinct breeds in Oman. Information was compiled from multiple sources to produce a comprehensive review on the breeding, management, economic and cultural use, …

The Study Of Dmrt1 In Zebrafish And How It Impacts Sex Determination, Raymond Michael Poirier

Graduate Masters Theses

The dmrt1 gene is common amongst most animals and functions to determine or maintain male sex during development. Similarly, in zebrafish dmrt1 is important for male sex determination and maintaining proper testis morphology. This gene is expressed in two different cell types of the testis in zebrafish, germ cells and Sertoli cells. While we know where this gene is expressed and what its role is, it is not known if it is sufficient to drive male fate. If so, then in which cells is it sufficient to drive male fate in the testis? I aimed to answer this question by …