Genetics and Genomics Commons^™

Pirna Expression In Regenerative Tissue Of Octopus Bimaculoides, Bailey Ervin

Honors Theses

Tissue regeneration is present in varying capacities across the animal kingdom. Animals such as Hydra and planarians have the capacity to regenerate entire bodies from extremely small sections of amputated tissue. Others, such as humans, have restricted capacities of regeneration, especially in terms of full appendages and specialized tissues such as cardiac and nervous tissue. One of the primary goals of studying regeneration in other organisms is to achieve the development of regenerative medicine. Interaction of P-element induced WImpy testis (PIWI) proteins and PIWI-interacting RNAs (piRNAs) have been implicated in germline genome maintenance, as well as transposable element silencing. Research …

Pirna Expression In The Tube Feet Of Lytechinus Variegatus, Reagan Milliet

Honors Theses

Tissue regeneration is an area of research with implications for medicine and animal health. While nearly all living multi-cellular organisms are capable of regeneration, there are major differences in the animal kingdom. Some organisms are capable of regenerating virtually every cell in their bodies. In hopes of engineering tissue regeneration for medical applications, the mechanisms by which organisms regenerate are being widely investigated. To better understand regeneration, the role of P-element Induced WImpy testis (PIWI) proteins are being evaluated. In collaboration with PIWIinteracting RNAs (piRNAs), PIWI proteins have been proven instrumental to transposon silencing and maintenance of the genome in …

Development Of A Novel Environmental Dna (Edna) Tool For Monitoring Vulnerable Freckled Guitarfish, Pseudobatos Lentiginosus, In The Western Central Atlantic, Sarah Toepfer

Honors Theses

Rhino-rays are the most threatened group of elasmobranchs, having experienced widespread declines due to mortalities in fisheries and habitat degradation. Within the Western Central Atlantic, there are two extant species of Rhino-rays, the Critically Endangered Smalltooth Sawfish, Pristis pectinata, and the Vulnerable Freckled Guitarfish, Pseudobatos lentiginosus. Although there is research committed to P. pectinata in this region, less is known about the distribution status of P. lentiginosus. Over the past 50 years, P. lentiginosus have undergone a presumed range contraction in U.S. waters; once found from North Carolina to Texas, and historically common in the north central …

Population Genetics Of Cownose Rays, Rhinoptera Spp. In The Western Atlantic, Helen Weber

Master's Theses

Using molecular tools (e.g., the NADH subunit II mitochondrial gene), this study was the first to document the Brazilian cownose ray, Rhinoptera brasiliensis, within the northwestern Atlantic (NWA), and was the first study to examine population structure in R. brasiliensis within the NWA or northern Gulf of Mexico (GMX), revealing novel insights into the population biology of the animal and extending its range by nearly 1,500 km. This study also examined the sympatrically occurring American cownose ray, R. bonasus, and found population structure between the NWA and the GMX and the NWA and the southwestern Atlantic (SWA). High …

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 …

Distribution, Abundance, And Population Genetics Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Mississippi, Luke Pearson

Dissertations

The southeastern United States is a freshwater turtle biodiversity hotspot, second only to southeastern Asia, and this region is inhabited by one of the largest freshwater turtles in the world: the alligator snapping turtle (Macrochelys temminckii). This species was heavily harvested from the 1960’s to the 1980’s for the turtle soup industry, apparently contributing to substantial, range-wide population declines. These declines, coupled with anthropogenic impacts on riverine and floodplain habitats, have led to M. temminckii being petitioned for federal listing under the U.S. Endangered Species Act; it is currently under review by the U.S. Fish and Wildlife Service …

Human 5’-Tailed Mirtrons Are Processed By Rnasep, Mohammad Farid Zia

Dissertations

Approximately a thousand microRNAs (miRNAs) are documented from human cells. A third appear to transit non-canonical pathways that typically bypass processing by Drosha, the dedicated nuclear miRNA producing enzyme. The largest class of non-canonical miRNAs are mirtrons which eschew Drosha to mature through spliceosome activity. While mirtrons are found in several configurations, the vast majority of human mirtron species are 5’-tailed. For these mirtrons, a 3’ splice site defines the 3’ end of their hairpin precursor while a “tail” of variable length separates the 5’ base of the hairpin from the nearest splice site. How this tail is removed is …

An Examination Of The Influence Of Multi-Scale Processes And Connectivity On The Population And Assemblage Dynamics Of Headwater Fishes, Josh P. Hubbell

Dissertations

Typified by their branching pattern, headwaters are numerically abundant as the density of these habitats increases with increasing distance from the base of a dendritic river system. Connectivity among headwaters is complex, resulting in the spatial isolation of populations. Headwater specialists have evolved a suite of traits that permit these species to permanently reside within these habitats. The spatial configuration and connectivity of headwaters has repercussions for metapopulations and meta-assemblages. I investigated how multi-scale processes and connectivity influenced the patch occupancy, coexistence, movement ecology, population structure, and gene flow of headwater specialists. In chapter two, I used occupancy modeling to …

Development And Use Of An Environmental Dna Tool To Monitor Recovery Of The Critically Endangered Smalltooth Sawfish, Pristis Pectinata, In The Northwest Atlantic, Ryan N. Lehman

Master's Theses

The Critically Endangered Smalltooth Sawfish, Pristis pectinata, was once common in the tropical and subtropical waters of the Atlantic Ocean; however, following global declines in range and abundance over the past century, individuals were restricted to the waters of south and southwest Florida (SWFL) by about the 1980’s. Recently, public encounter reports have emerged in historically occupied habitats in United States waters, suggesting individuals are present in, or re-occupying, these areas, although the status of P. pectinata outside of SWFL is not currently well understood. Targeted environmental DNA (eDNA) surveys were chosen to assess the occurrence of P …

Assessment Of Genetic Diversity In Largetooth Sawfish, Pristis Pristis, Populations Over The 20th Century, Ann Fearing

Master's Theses

The Critically Endangered Largetooth Sawfish, Pristis pristis, experienced global declines in range and abundance over the past century and Australia is now their last stronghold. This research aimed to understand whether these declines have been accompanied by a reduction in levels of genetic diversity. Using P. pristis tissue samples sourced from natural history specimens, three fragments (616-bp, 386-bp, 141-bp) in the mitochondrial DNA (mtDNA) control region were PCR-amplified. At each fragment, significant genetic structure was found in P. pristis overall (Φ_ST=0.946, N=9; 0.813, N=54; 0.771, N=99). The Indo-West Pacific and Atlantic/Eastern Pacific each harbor genetically distinct lineages of …

The Ecology And Evolutionary History Of Two Musk Turtles In The Southeastern United States, Grover Brown

Dissertations

Turtles are among one of the most imperiled vertebrate groups on the planet with more than half of all species worldwide listed as threatened, endangered or extinct by the International Union of the Conservation of Nature. The Southeastern United States is a global biodiversity hotspot for turtles, and it likely represents the last area on the planet of both high diversity and high abundance of turtle species. In the past century, there has been an exponential increase in the number of publications on turtles in the United States and Canada, however a recent review of the literature suggests that this …

Genetic Homogeneity Of The Invasive Lionfish Across The Northwestern Atlantic And The Gulf Of Mexico Based On Single Nucleotide Polymorphisms, R. Pérez-Portela, A. Bumford, B. Coffman, S. Wedelich, M. Davenport, Alex Fogg, M.K. Swenarton, F. Coleman, M.A. Johnston, D.L. Crawford, M.F. Oleksiak

Student Publications

Despite the devastating impact of the lionfish (Pterois volitans) invasion on NW Atlantic ecosystems, little genetic information about the invasion process is available. We applied Genotyping by Sequencing techniques to identify 1,220 single nucleotide polymorphic sites (SNPs) from 162 lionfish samples collected between 2013 and 2015 from two areas chronologically identified as the first and last invaded areas in US waters: the east coast of Florida and the Gulf of Mexico. We used population genomic analyses, including phylogenetic reconstruction, Bayesian clustering, genetic distances, Discriminant Analyses of Principal Components, and coalescence simulations for detection of outlier SNPs, to understand …

Evolution In Light Of Mitonuclear Landscapes: An Examination Of Mitochondrial Replacement In Killifish (Fundulus Spp.), Stephen D. Flanagan

Dissertations

The mitochondria are responsible for the bulk of energy production in eukaryotes. They possess their own genome that works in conjunction with the nuclear genome to accomplish the extraordinarily important task of energy conversion. When species hybridize there will be a mismatch in evolutionary histories between these two genomes. The deleterious interactions of these genomes have been studied in great detail (i.e. hybrid breakdown). However, little work has been conducted to understand the population genetic, and morphological consequences of wide-ranging replacement. The Fundulus notatus complex is comprised of 3 species: F. notatus, F. olivaceus, and F. euryzonus. …

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 …

Ecology And Genetics Of Lungless Salamanders (Family Plethodontidae) In The Gulf Coastal Plain, Jennifer Yasmin Lamb

Dissertations

During the last half century, lungless salamanders (Family Plethodontidae) have been the subject of numerous studies in the fields of ecology and genetics. While most works have focused on the species-rich Eastern Highlands region, there has been a recent shift towards plethodontid assemblages within the Coastal Plain. The research presented herein applies hierarchical occupancy models and both mitochondrial and nuclear genes to address questions pertinent to the biology and conservation of plethodontids within the Gulf Coastal Plain. The results of a multi-species Bayesian single-season occupancy model indicated that two environmental gradients, upstream drainage area and stream drying, influenced the probability …

Endohelminth Parasites Of Some Midwater And Benthopelagic Stomiiform Fishes From The Northern Gulf Of Mexico, Michael J. Andres, Mark S. Peterson, Robin M. Overstreet

Gulf and Caribbean Research

: Mesopelagic fishes represent significant ecological links between mesozooplankton and the larger pelagic squids, fishes, and marine mammals. As such, these fishes also play a significant role as intermediate or paratenic hosts for parasites that require a crustacean intermediate host and mature in marine mammals or pelagic fishes. We examined a total of 208 individuals representing 5 species of Sternoptychidae and 88 individuals representing 2 species of Phosichthyidae from 20 locations in the northern Gulf of Mexico (nGOM). Six of the 7 species we examined are mesopelagic and one species was benthopelagic. We found the larval stages of Anisakis brevispiculata …

Deciphering The Functional Collaboration Of Mid And Bric-A-Brac 2 As Potential Regulators Of Cellular Proliferation Within Adult Drosophila Ovaries, Petra Visic

Master's Theses

Stem cell niches are highly organized and specialized microenvironments located within specific tissues of both vertebrate and invertebrate organisms [1]. In Drosophila melanogaster, three distinct stem cell niches have been identified within the ovary including the germline stem cell (GSC), follicle stem cell (FSC), and escort stem cell (ESC) niche. Recently, Fregoso-Lomas et al. [2] reported that Gurken/Epidermal Growth Factor Receptor (EGFR) signaling is modulated within posterior ovarian follicle cells by Midline (Mid). The mid gene encodes a T-box transcription factor protein that specifies cell fates in the developing heart [3][4], central nervous system [5][6], epidermis [7], and eye …

The Conservation Genetics Of Two Emydid Turtles: Emydoidea Blandingii And Malaclemys Terrapin, Charlotte Lizana Petre

Master's Theses

Conservation of turtles is complicated by their sensitivity to habitat degradation and overexploitation. I used microsatellites and standard population genetic analyses to explore genetic diversity, population structure, paternity and demographic history in two emydid turtles that are currently experiencing threats to their survival. The Blanding’s turtle, Emydoidea blandingii, has experienced habitat fragmentation throughout its range, and this study focuses on a population in Massachusetts where hatchlings from one population are being translocated to establish a new population. I found evidence of multiple paternity within clutches and found no significant reduction in genetic diversity when comparing the source population and …

Bridging Functional Genomics And Toxicogenomics Through Dna Microarrays In A Fish Model, Shuzhao Li

Dissertations

In a case study of finding gene expression signatures for environmental stressors in Cyprinodon variegatus, this dissertation examines several important issues of applying DNA microarray technology to fish toxicogenomics. The most relevant disciplines, fish toxicogenomics and computational systems biology are reviewed in Chapter 1. Chapter 2 reviews major aspects of DNA microarray technology.

On DNA microarrays, even for probes that target the same transcript, large variations are seen in the probe signals. These variations are partly dependent and partly independent on probe sequences. Chapter 3 estimates the sequence independent variation by combining experimental and computational approaches. Chapter 4 and …