Genetics and Genomics Commons^™

A Case Of Incipient Budding Speciation In The California Floristic Province, Infraspecific Divergence In Abronia Villosa, Eli J. Allen

Cal Poly Humboldt theses and projects

Physical barriers to gene flow are the traditional evidence for species divergence. Conversely, there has been increasing acknowledgment of speciation in the face of gene flow as an evolutionary process. Budding speciation involves peripheral populations adapting to local ecological conditions, thereby budding off from a widespread progenitor species. Budding speciation is distinguished by ecological divergence and is generally evidenced by asymmetrical range size and nested phylogenetic relationships of sister species. The narrow endemic Abronia villosa var. aurita is adapted to montane sandy washes adjacent to its widespread sister variety, the desert dwelling var. villosa. Here, I tested the hypothesis …

Evaluating The Utility Of Tracers To Characterize Environmental Dna Transport And Inform Detection Of Fishes In Small Streams, Gavin B. Bandy

Cal Poly Humboldt theses and projects

This study was motivated by the need to develop a noninvasive and highly sensitive monitoring tool for determining local occupancy of an endangered aquatic species To make inference into the occupancy of fishes within small stream sites, we developed a method to determine whether environmental DNA (eDNA) concentrations from a target species were elevated relative to a tracer, formulated to mimic eDNA and introduced at a single location. We examined patterns in the observed distribution of the tracer to account for the effects of site-specific transport processes and sampling on distributions of naturally occurring eDNA at small spatial scales (400 …

Quantitative Trait Loci Influencing Elemental Content In Grapevine Leaves, Jesse L. Krokower

MSU Graduate Theses

In grapevine, the influence of the plant’s elemental composition (the ionome) on fruit and wine quality is well established, but its genetic underpinnings have received limited scientific attention. In this study, I analyzed the leaf ionome of 131 interspecific F1 hybrid progeny plants from a cross between a Vitis rupestris Scheele (♀) and a Vitis riparia Michx (♂) parents, which were replicated in four different environments: Southwest Missouri, Central Missouri, South Dakota, and New York. I sampled leaves at three different times during the growing season at all four locations and had the concentration of 20 elements measured using ICP-MS. …

Range-Wide Analysis Of The Genetic Diversity And Genetic Structure Of The Spotted Turtle (Clemmys Guttata), Madison S. Whitehurst

Theses and Dissertations

Understanding the spatial distribution of genetic diversity and structure in endangered species is vital for effective conservation management. This research discusses the results of an initial analysis of the genetic structure and variation of the spotted turtle (Clemmys guttata), a species of conservation interest. The study sampled 913 individuals from 78 unique locales across 16 states in the eastern portion of the species' range. Utilizing ddRADSeq, a de novo genome assembly was developed to identify nearly 20,000 potential loci. A total of 926 were selected for this analysis. Results revealed no spatial clustering of genetic diversity or structure, …

The Genetic Basis Of Two Reproductive Traits In Monkeyflowers: Stigma Closure And Corolla Carotenoids, Rachel Anne Halperin

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Abstract

The interactions between pollinators and flowers have long been a driving force for the evolution of many physical floral traits. Traits such as flower shape, size, color, and smell are just some of these traits that evolve because of these interactions. This evolution does not only occur in the more obvious morphological floral traits, however, but also in more subtle traits like touch sensitive stigma closure. In hundreds of Lamiales species, the bilobed stigma, the organ that receives pollen from pollinators, closes rapidly upon touch. Theory and experiments show that this novel dynamic reproductive trait increases pollen export and …

The Function Of Protein Glutamylation In Vision, Rawaa Aljammal

Graduate Theses, Dissertations, and Problem Reports

Posttranslational glutamylation of protein has emerged as a novel candidate for cellular integrity. In a dynamic process, Tubulin Tyrosine Ligase Like proteins (TTLLs) introduce glutamate groups to their substrates, while Cytosolic Carboxypeptidases members (CCP1-CCP6) remove these glutamate groups. The outcome of this interplay is a wide range of substrates; each is glutamylated to a level crucial for its function.

Protein glutamylation is particularly abundant in neurons and in the axoneme of cilia and flagella. This distribution, along with the correlation between imbalanced glutamylation levels and compromised cellular functions, underscores the significance of protein glutamylation in maintaining cellular viability. However, the …

Mitochondrial Adaptation In The Green Crab Hybrid Zone Of The Gulf Of Maine, Jared Lynch

Honors Projects

The mitochondrial genome has historically been relegated to a neutral genetic marker, but new evidence suggests mitochondrial DNA to be a target for adaptation to environmental stress. The invasive European green crab (Carcinus maenas) exemplifies this in the Gulf of Maine’s hybrid zone, where interbreeding populations exhibit thermal tolerances influenced by mitochondrial genotype. To better understand the mechanism behind this phenomenon, the effect of mitochondrial genotype on mitochondrial activity was tested by measuring mtDNA copy number (mtCN) and the activity of complex I, II, and IV of the electron transport system via high-resolution respirometry. Mitochondria isolated from frozen …

Do Duckweeds Adapt To Water And Microbes?, Ava M. Rose

Honors Theses and Capstones

Organisms in their home environment sometimes outperform transplanted individuals native to other areas, in a phenomenon termed local adaptation. While local adaptation is traditionally considered to be driven by the abiotic factors of an environment, scientists have recently increased consideration of biotic factors. Specifically, of interest to many is host-associated microbiomes, which can alter host trait expression. As the desire to commercialize microbiome treatments for agriculture and medicine grows, it is important to analyze the potential value of local microbiomes, which may be adapted to their hosts, or to which local hosts may have adapted. Using Lemna minor (duckweed) as …

Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin

Biology Dissertations

Mycobacteria encompass many pathogenic species known to cause severe disease in humans. A well-known example is Mycobacterium tuberculosis (Mtb), the causative agent of the lung disease tuberculosis, which kills millions of humans worldwide yearly. Pathogenic mycobacteria like Mtb are challenging to treat because of their innate ability to adapt to environmental stress. Their unique cell physiology and conserved stress responses allow them to combat biological insults, regulate growth, and regulate genes involved in stress; all these responses increase tolerance to antibiotics. The current therapies to treat mycobacterial infections are lengthy and, at times, unsuccessful, partly due to antibiotic tolerance. A …

Csn-5: A Tumor's Friend Or Foe In The C. Elegans Germline?, Kellie C. Kuch

Graduate Student Theses, Dissertations, & Professional Papers

The COP9 signalosome is a highly conserved eukaryotic complex regulating protein degradation via deneddylation of Cullin-RING E3 ligases. CSN5, the COP9’s fifth component, contains the catalytically active domain for CSN deneddylation. The complex is inactive without CSN5; however, CSN5 engages in COP9-independent binding with several other proteins, typically promoting either destruction or stabilization of its partners. Many of its confirmed interaction partners are also implicated in tumorigenesis (prominent examples being p27 and p53) and a complex cancer interactome has been established for CSN5. Additionally, CSN5 overexpression has been documented in a staggering array of cancers of diverse origins. This discovery …

Chemical Synthesis Of Sensitive Dna, Komal Chillar

Dissertations, Master's Theses and Master's Reports

Over the past decades, researchers have tried various chemical methods to synthesize modified oligodeoxynucleotides (ODNs, i.e. short segments of DNAs). Traditional ODN synthesis methods require strong basic, and nucleophilic conditions for the deprotection and cleavage of the ODN from the solid support. However, the sensitive ODNs containing labile functionalities are vulnerable to such harsh conditions. Sensitive ODNs have a wide range of applications in research and pharmaceuticals. To synthesize sensitive ODNs, researchers devised different strategies but no practical methods have been developed. To overcome these challenges, we developed alkyl Dim alkyl Dmoc technology. This innovative technology uses weakly basic and …

Model-Based Deep Autoencoders For Clustering Single-Cell Rna Sequencing Data With Side Information, Xiang Lin

Dissertations

Clustering analysis has been conducted extensively in single-cell RNA sequencing (scRNA-seq) studies. scRNA-seq can profile tens of thousands of genes' activities within a single cell. Thousands or tens of thousands of cells can be captured simultaneously in a typical scRNA-seq experiment. Biologists would like to cluster these cells for exploring and elucidating cell types or subtypes. Numerous methods have been designed for clustering scRNA-seq data. Yet, single-cell technologies develop so fast in the past few years that those existing methods do not catch up with these rapid changes and fail to fully fulfil their potential. For instance, besides profiling transcription …

Dna Methylation-Based Epigenetic Biomarkers In Cell-Type Deconvolution And Tumor Tissue Of Origin Identification, Ze Zhang

Dartmouth College Ph.D Dissertations

DNA methylation is an epigenetic modification that regulates gene expression and is essential to establishing and preserving cellular identity. Genome-wide DNA methylation arrays provide a standardized and cost-effective approach to measuring DNA methylation. When combined with a cell-type reference library, DNA methylation measures allow the assessment of underlying cell-type proportions in heterogeneous mixtures. This approach, known as DNA methylation deconvolution or methylation cytometry, offers a standardized and cost-effective method for evaluating cell-type proportions. While this approach has succeeded in discerning cell types in various human tissues like blood, brain, tumors, skin, breast, and buccal swabs, the existing methods have major …

Investigating The Impact Of Transcription On Mutation Rates, Sarah Patterson

Theses and Dissertations

tRNA genes are highly transcribed and perform one of the most fundamental cellular functions. Although a universal pattern observed across all three domains of life is that highly transcribed genes tend to evolve slowly, tRNA genes have been shown previously to evolve rapidly. This rapid sequence evolution could result from relaxed selection, increased mutation rate, or a combination of both. Here, we use mutation-accumulation line sequencing data to show that tRNA genes accumulate more mutations than other gene types. Our results indicate that this elevated mutation rate is a consequence of both elevated transcription-associated mutagenesis and a lack of transcription-coupled …

Towards Understanding The Interactions Between Ospreys And Human-Made Structures In The Tennessee River Valley, Natasha Karina Murphy

Theses and Dissertations

Raptor nests on human-built structures represent a significant source of conflict as they can result in bird mortality, fires, structure damage, service distribution, or power outages when falling nest materials or animals connect with energized conductors. Power companies, such as the Tennessee Valley Authority (TVA), wish to mitigate these conflicts to avoid service disruptions. In this dissertation, I present my work towards understanding and mitigating the interactions between Ospreys (Pandion haliaetus) and human-made structures. To achieve this, I explored multiple elements of conflict identification, monitoring, and basic ecology of the target species to better inform conflict mitigation. In Chapter I, …

Exploring Soil Microbial Dynamics In Southern Appalachian Forests: A Systems Biology Approach To Prescribed Fire Impacts, Saad Abd Ar Rafie

Doctoral Dissertations

Prescribed fires in Southern Appalachian forests are vital in ecosystem management and wildfire risk mitigation. However, understanding the intricate dynamics between these fires, soil microbial communities, and overall ecosystem health remains challenging. This dissertation addresses this knowledge gap by exploring selected aspects of this complex relationship across three interconnected chapters.

The first chapter investigates the immediate effects of prescribed fires on soil microbial communities. It reveals subtle shifts in porewater chemistry and significant increases in microbial species richness. These findings offer valuable insights into the interplay between soil properties and microbial responses during the early stages following a prescribed fire. …

Characterization Of Radiotolerance In Potato And Development Of A Gamma Radiation Phytosensor., Robert Graham Sears

Doctoral Dissertations

As humans pursue space travel and nuclear energy, the risk of harm from ionizing radiation increases. On Earth or in space, plants are essential to our personal and environmental health. Plants serve as sentinels, bioremediators and food sources in areas of high ionizing radiation, therefore it is essential to understand how ionizing radiation affects plant biology. This work aimed to understand plant responses to ionizing radiation in the potato chassis and apply that knowledge to generate novel phenotypes for nuclear energy and space applications. The first gamma radiation phytosensor was developed for monitoring at standoff distances greater than three meters. …

Characterization Of Lignin Structural Variability And The Associated Application In Genome Wide Association Studies, Nathan D. Bryant

Doctoral Dissertations

Poplar (Populus sp.) is a promising biofuel feedstock due to advantageous features such as fast growth, the ability to grow on marginal land, and relatively low lignin content. However, there is tremendous variability associated with the composition of biomass. Understanding this variability, especially in lignin, is crucial to developing and implementing financially viable, integrated biorefineries. Although lignin is typically described as being comprised of three primary monolignols (syringyl, guaiacyl, p-hydroxyphenyl), it is a highly irregular biopolymer that can incorporate non-canonical monolignols. It is also connected by a variety of interunit linkages, adding to its complexity. Secondary cell wall …

Regulation Of Protein Synthesis In Arabidopsis Thaliana Through A Bioinformatic And Mathematical Lens, Ricardo Andres Urquidi Camacho

Doctoral Dissertations

Organisms exist under constantly varying environmental and internal conditions, which necessitate the differential regulation of gene expression. To synthesize proteins, the ribosome translates the information encoded in the nucleotide sequence of an mRNA into the final, functional amino acid sequence. Knockouts of ribosomal proteins lead to lethality. One such protein is the ribosomal protein 6 of the small subunit (eS6/RPS6). We confirmed that the knockout of either one of two eS6 paralogs in Arabidopsis leads to stunted growth and chlorosis. Here, these phenotypes have been further characterized in seedlings by precisely quantifying the ribosome loading of mRNAs as well as …

A Study Of The Snd1/Prmt5 Axis In Liver Cancer By Genetic Mouse Models, Tanner Wright, Tanner Wright

Dissertations & Theses (Open Access)

Arginine methylation is an essential post-translational modification (PTM) in cells. Protein arginine methyltransferase 5 (PRMT5) is the primary enzyme that catalyzes symmetric dimethyl arginine (SDMA) and requires methylosome protein 50 (MEP50) for stability and enzymatic activity which are necessary for life and development. Effector proteins bind different types of PTM’s to facilitate signaling. Staphylococcal nuclease Tudor domain containing 1 (SND1) is an effector that specifically binds SDMA via its single C-terminal Tudor domain. Both SND1 and PRMT5 have been implicated in hepatocellular carcinoma (HCC). SND1 has been confirmed as a driver of HCC using genetically engineered mouse models (GEMMs), though, …

Novel Microbial Guilds Implicated In N2o Reduction, Guang He

Doctoral Dissertations

N₂O is a long-recognized greenhouse gas (GHG) with potential in global warming and ozone depletion. Terrestrial ecosystems are a major source of N₂O due to imbalanced N₂O production and consumption. Soil pH is a chief modulating factor controlling net N₂O emissions, and N₂O consumption has been considered negligible under acidic conditions (pH <6). In this dissertation, we obtained solids-free cultures reducing N₂O at pH 4.5. Furthermore, a co-culture (designated culture EV) comprising two interacting bacterial population was acquired via consecutive transfer in mineral salt medium. Integrated phenotypic, metagenomic and metabolomic analysis dictated that the Serratia population excreted certain …

Effect Of Plant Genotype On Plant-Microbe Interactions And Multi-Generation Ecosystem Selection Of Microbial Communities Associated With Plant Biomass In Arabidopsis Thaliana, Nachiket Shankar

Graduate Doctoral Dissertations

The microbiome's role in shaping host phenotypes is a critical area of investigation, with implications for ecology, evolution, and host health. Dynamic plant-microbe interactions are influenced by factors like soil type, environment, and genotype. Understanding their impact on microbial communities is key for tailored plant benefits. An artificial ecosystem selection experiment was done for eight generations with Arabidopsis thaliana Ler and Cvi. This revealed distinct microbial communities shaped by genotypes and biomass treatments. Initially, environment dominated, but over time, genotype and biomass gained influence, explaining ~40% of the variation. Moreover, genotype-specific rhizobacterial associations were observed, enhancing understanding of community dynamics …

Genomic Characterization Of Adolescent And Young Adult Cancers: Investigation Of Ewing Sarcoma Susceptibility And Chornobyl Thyroid Tumors, Olivia Lee

Dissertations & Theses (Open Access)

Adolescent and young adult (AYA) cancers, diagnosed between the ages of 15 and 39, can exhibit distinctive genetic and molecular characteristics. Reported epidemiologic findings and treatment outcomes based on pediatric and adult cancer studies are often not suitable for application to the AYA population, underscoring the need for more thorough genomic research. Advances in sequencing technologies have enabled comprehensive analyses of complex genomic characteristics of AYA cancers, crucial for understanding the underlying biology of these malignancies. Here, I have utilized advanced sequencing techniques and integrated analytic approaches to describe important genomic features in two different AYA cancer types: Ewing Sarcoma …

Characterization Of Developmental Phenotypes In Zebrafish With Mutations In Mmachc, Briana Elise Pinales

Open Access Theses & Dissertations

Methylmalonic aciduria and homocystinuria, CblC type (cblC) syndrome (MIM 277400) is a genetic disorder resulting from a mutation in the MMACHC gene. This gene plays a crucial role as a chaperone in the conversion of vitamin B12 into its active form, which is essential for proper cellular metabolism. cblC syndrome is heterogenous by nature, primarily attributed to the extensive damage it causes across multiple bodily systems. In cases of early onset of cblC syndrome, patients may exhibit a diverse range of clinical symptoms including difficulties with feeding, dysmorphic features, microcephaly, brain abnormalities, hypotonia, developmental delays, and seizures. The study of …

The Discovery Of A Novel Bacteria From A Large Co-Assembly Of Metagenomes, Matthew Finkelberg

Masters Theses

In the summer of 2022, a co-assembly of metagenome was created using the microbes found at Barres Woods in Harvard Forest. 14 samples were taken, and sample was split into the organic and mineral layer, which totals 28 Bulk MAGs. Within this Co-assembly, 4 different genomes were found which were designated with the phylum of FCPU426. Three of which were considered medium quality and one being assigned high quality. The novel phyla first appeared in NCBI and GTDB databases in June 2018. The name FCPU426 dates to 2010 and was named based on the 16s amplicon sequencing.

The novel phylum …

Tracing Evolution Of Gene Transfer Agents Using Comparative Genomics, Roman Kogay

Dartmouth College Ph.D Dissertations

The accumulating evidence suggest that viruses and their components can be domesticated by their hosts, equipping them with convenient molecular toolkits for various functions. One of such domesticated system is Gene Transfer Agents (GTAs) that are produced by some bacteria and archaea. GTAs morphologically resemble small phage-like particles and contain random fragments of their host genome. They are produced only by a small fraction of the microbial population and are released through a lysis of the host cell. Bioinformatic analyses suggest that GTAs are especially abundant in the taxonomic class of Alphaproteobacteria, where they are vertically inherited and evolve …

Population Genomics, Ecology And Conservation Of Asterias Sea Stars In The North Atlantic, Melenia I. Giakoumis

Dissertations, Theses, and Capstone Projects

Uncovering how species respond to environmental change is a central question in biology (Ehrlén & Morris 2015; Habibullah et al. 2022). It is the key to elucidating the past, understanding the present and predicting the future of species’ population dynamics. This dissertation investigates the influence of environmental change on intertidal species’ distributions and genomics at several timescales, with implications for conservation.

Environmental changes have occurred throughout history, on a geological scale, and have shaped the global patterns of species’ distributions and population sizes. Biologists have long studied how geological history has shaped species distributions (Sanmartín 2012) in both terrestrial (Liu …

Characterization Of Pathological Tau Mutants, Charles J. Mcdonald

Dissertations, Theses, and Capstone Projects

Tau is a protein expressed exclusively in glia and neurons in the central nervous system and implicated in several neurogenerative diseases called “tauopathies”. Among all the tauopathies, one third is characterized by the presence of genetic mutations leading to the synthesis of tau proteins with single amino acid substitutions at specific locations and affecting protein function. While most of the initial studies have emphasize the functional role of tau as modulator of the axonal cytoskeleton, it has recently been well accepted that tau is also an intrinsically disordered protein that tends to form membraneless organelles called coacervates, due to a …

Predicting Marine Teleost Responses To Ocean Warming And Pollution, Akila Harishchandra

Electronic Theses and Dissertations

Ocean warming and pollution are two detrimental anthropogenic factors causing rapid marine ecosystem degradation recorded in the past decades. These factors alter the marine environment intolerable for many marine species, forcing them to either adapt or shift their contemporary habitat ranges to reduce the extinction risk embedded with environmental degradation. Estimating marine species’ habitat range shifts, and their potential for developing adaptive mechanisms are critical for ecosystem conservation and management, human health risk assessment, and climate change vulnerability assessments. Given that, for the first chapter of this thesis, we focused on developing a species distribution model (SDM) integrating marine species …

Genetic Effects Of Anthropogenic Disturbance On Native Charrs, Brad Erdman

Electronic Theses and Dissertations

Artificial propagation has been utilized for over a century to offset anthropogenic declines of abundance for many fishes. Complex and poorly documented histories of habitat degradation and stockings have resulted in considerable uncertainty regarding whether contemporary populations are of native, hatchery, or mixed origins. This uncertainty is problematic as it precludes prioritizing the conservation of native populations that are postulated to possess local adaptations and greater evolutionary potential. Population genetics can assess the relative reproductive contributions of previous stocking events and in this dissertation I apply these methods to four empirical studies of native charr (genus Salvelinus) that have …