Genomics Commons^™

A Fine-Scale Genomic Study Of Cheat Mountain Salamanders (Plethodon Nettingi) On Managed Public Land, Amylynn Nicole Ephraim

Graduate Theses, Dissertations, and Problem Reports (ETD)

Habitat fragmentation has the potential to isolate localized populations, particularly those which are understood to have limited dispersal capabilities. This isolation can reduce genetic diversity through the effects of inbreeding depression, and small populations are more susceptible to the impacts of genetic drift. In this study, I aim to understand the level of genetic connectivity between known occupied patches of Cheat Mountain salamanders (Plethodon nettingi; CMS) on managed public land. CMS are a federally threatened, high-elevation, West Virginia endemic species associated with red spruce (Picea rubens) forests. I used double-digest restriction site associated DNA (ddRAD) sequencing …

Population Genomics Of Pacific Herring Spawning Aggregations In The Eastern Bering Sea, Sydney A. Almgren

Fisheries

Pacific herring (Clupea pallasii) is a critical forage fish to the marine environment, economy, and culture of Alaska. However, despite the importance of Pacific herring in Alaska and throughout the North Pacific, knowledge gaps exist for foundational genomic characteristics of the species, including genetic population structure and the basis of genetic sex determination. In this thesis, I addressed these knowledge gaps using low coverage, whole genome sequencing. I assessed population structure and genetic diversity across seven sampling sites and found three genetic populations: Unalaska, the farthest south sampling location, Kotzebue, the farthest north, and a third group unassociated with geographic …

Genomic Structure Among Populations Of A Regionally Rare Perennial Plant Indicates The Need For Reevaluation Of Management Units, Cheyenne Moore, Angela J. Mcdonnell, Scott Schuette, Christopher T. Martine

Faculty Journal Articles

Conservation of rare species often relies on the delineation of management units and genomic tools can now be applied for this purpose. However, this is not as common on a local scale, where populations are often small and fragmented, despite the utility of informing conservation and management practice at the regional level. We use a genotyping by sequencing (GBS) approach to assess the perennial riparian plant species Baptisia australis (Fabaceae) in Pennsylvania, where the taxon is at the edge of its natural distribution and considered threatened. In this system, we investigate whether sampled subpopulations exhibit genetic structure. We find that …

Preservation Of Genetic Diversity And Selection Over A Century In A Coral Reef Fish (Taeniamia Zosterophora) In The Philippines, Kyra S. Fitz, Rene A. Abesamis, Jemelyn Grace P. Baldisimo, Abner A. Bucol, René D. Clark, Eric Garcia, Ivan R. Lopez, Sharon F. Magnuson, Marial J. Malabag, Richard N. Muallil, Lynne R. Parenti, Brendan R. Reid, Mudjekeewis D. Santos, Christopher E. Bird, Kent E. Carpenter, Malin L. Pinsky

Biological Sciences Faculty Publications

Evaluating the evolutionary impacts of anthropogenic activity on populations is key to understanding species resiliency and to designing effective conservation strategies. Sequencing DNA from historical specimens provides the opportunity to establish a historical baseline and empirically assess changes in genetic diversity, changes in effective population size, and selection over time. Here, we sequenced historical and contemporary samples of the cardinalfish Taeniamia zosterophora collected in 1908 and in 2021-2022 across two sites with differing human impact in the Philippines. At both sites, genetic diversity increased over time, with contemporary samples having significantly higher Watterson's Θ than historical samples. This diversity increase …

Assessment Of The Genetic Population Structure And Extent Of Clonality In A Rare Serpentine Endemic, Lathyrus Biflorus T.W. Nelson & J.P. Nelson (Fabaceae), Using Ddrad Sequencing, Ashley Dickinson

Cal Poly Humboldt theses and projects

Lathyrus biflorus, or the two-flowered pea, is a rare herbaceous perennial restricted to a single population in Northern California. The species is considered critically imperiled but remains unprotected under state or federal endangered species acts. Despite its rarity, little is known about its life history, reproductive biology, or genetic diversity. Using genome-wide reduced representation sequencing, this study aimed to address these gaps by investigating the molecular evidence of clonality, the number and diversity of genets (unique genetic individuals which can be made up of one or many clonal units or ramets), and overall genetic health of the population. My …

Conservation Genomic Investigation Of A Threatened Trout Species Endemic To The Gila River, David Thomas Camak

Biology ETDs

Climate change is a looming threat to the persistence of species, especially aquatic, imperiled species. Species native to desert streams are at a particular disadvantage, as many species already face drought, floods, wildfires, and threats from nonnative species, all of which are thought to be exacerbated by climate change. Species such as the threatened Gila Trout (Oncorhynchus gilae) already have small ranges and persist in fragmented and isolated habitats that limits gene flow between populations. Therefore, it is important to understand the current genomic status of such populations to be able to predict the future effects of climate …

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 …

Illuminating The Drivers Of Genomic Diversification In Lamprologine Cichlids Of The Lower Congo River, Naoko P. Kurata

Dissertations, Theses, and Capstone Projects

Freshwater fishes are extraordinarily diverse, considering their available habitats represent a tiny proportion of the earth’s surface. Rivers connect heterogeneous habitats in a linear form and provide excellent simplified models to understand how aquatic biodiversity evolves. In particular, the lower Congo River (LCR) in west Central Africa consists of a dynamic hydroscape exhibiting extraordinary aquatic biodiversity, endemicity, and morphological and ecological specialization. This system is thus an excellent natural laboratory for understanding complex speciation and population diversification processes. In my research, I explore various drivers of diversification, and adaptive evolution in rheophilic lamprologine cichlids endemic to the LCR, including Lamprologus …

Genomic Approaches To Uncovering The Coevolutionary History Of Parasitic Lice [Review], Kevin P. Johnson

Harold W. Manter Laboratory of Parasitology: Library Materials

Next-generation sequencing technologies are revolutionizing the fields of genomics, phylogenetics, and population genetics. These new genomic approaches have been extensively applied to a major group of parasites, the lice (Insecta: Phthiraptera) of birds and mammals. Two louse genomes have been assembled and annotated to date, and these have opened up new resources for the study of louse biology. Whole genome sequencing has been used to assemble large phylogenomic datasets for lice, incorporating sequences of thousands of genes. These datasets have provided highly supported trees at all taxonomic levels, ranging from relationships among the major groups of lice to those among …

Genetic Diversity & Connectivity Of Chasmanthium Latifolium (Poaceae) In Pennsylvania & The Effect On Conservation Status Of A Rare Species, Jonathan D. Hayes

Honors Theses

Chasmanthium latifolium (Michx.) Yates (Poaceae) is a loosely colonial, rhizomatous, perennial grass species that lives in riparian habitats, making it fittingly referred to as river oats. Native to the southern Midwest and the eastern half of the United States, C. latifolium reaches the northeastern edge of its range in Pennsylvania. Within Pennsylvania, eleven extant C. latifolium populations are found along four waterways: the Monongahela River, the Susquehanna River, and two tributaries to the Susquehanna River. This limited state distribution exhibits an east-west disjunct distribution, where western populations are largely separated from eastern populations with one centrally located population. Between the …

Investigation Into The Genetic Provenance Of Three Rare Plants With East-West Disjunction Patterns In Pennsylvania., Scott Schuette, Christopher T. Martine

Other Faculty Research and Publications

Rare plant conservation relies on an understanding of the natural history, biology and ecology, and real and potential threats to their populations to inform state regulations that serve to protect the species from extirpation. This work often involves extensive field surveys over several years to determine population sizes and whether those populations are seeing reductions in number of individuals necessary to maintain the genetic diversity within and between those populations. Species and populations with high genetic diversity are better equipped to withstand sudden changes to their habitats that derive from land use changes and changing climate. There are a variety …

Lepidopteran Granivory Reduces Seed Counts In A Rare Species Of Riparian Scour Prairies, Cheyenne Moore, Angela J. Mcdonnell, Scott Schuette, Christopher T. Martine

Faculty Journal Articles

In Pennsylvania Baptisia australis var. australis is found along only four waterways: the Allegheny River, Youghiogheny River, Clarion River, and Red Bank Creek. Because of its limited distribution and small number of extant populations, the species is considered state-threatened in Pennsylvania. In addition, the riparian prairie habitat that Pennsylvania Baptisia australis var. australis is restricted to is also in decline and considered vulnerable. Because of these conservation concerns, insights into the natural history of the taxon in the state is valuable and will inform conservation efforts. Field surveys and fruit collections along the Allegheny River and herbarium collections were used …

Genetic Diversity Of Blue Wildebeest (Connochaetes Taurinus) In The Liuwa Plain Of Zambia, Stephanie J. Szarmach

All NMU Master's Theses

Advances in DNA sequencing are enabling researchers to identify and genotype large sets of single nucleotide polymorphisms (SNPs) in non-model organisms to answer questions concerning ecology, evolution, and conservation. Analysis of SNP allele frequencies can provide insight into the amount of genetic diversity present in a population, connectivity between populations, and historical demographic changes. The blue wildebeest (Connochaetes taurinus) plays an important ecological role in many African savanna ecosystems, but little is known about the level of genetic diversity within most populations or the amount of gene flow that occurs between populations. In particular, the wildebeest in the …

Development Of Genomic Resources For The Evaluation Of Red Snapper, An Emerging Species Candidate For Marine Aquaculture And Stock Enhancement, Adrienne Elise Norrell

Master's Theses

The northern red snapper (Lutjanus campechanus) is a highly targeted reef fish candidate for marine aquaculture and stock enhancement in the southern United States. This work aimed to develop genomic resources for the genetic management of aquaculture programs and to investigate population structure using high-throughput sequencing technologies. Eighty-four new microsatellite markers were developed through screening of Illumina paired-end sequencing reads. Microsatellite loci and Single Nucleotide Polymorphisms (SNPs) generated through Restriction Site Associated DNA (RAD) sequencing were assayed in 5 outbred full-sib families to construct a high-density linkage map of the red snapper genome. The map consists of 7,964 …