Molecular Genetics Commons^™

Dna Methylation And The Response To Infection In Introduced House Sparrows, Melanie Gibson

Electronic Theses and Dissertations

Epigenetics is the study of molecular modification of a genome without changing its base pairs. The most studied type of epigenetic mechanism is DNA methylation, which is capable of turning a gene “on” or “off.” Epigenetic potential is the capacity to which an individual can have methylation on its genome. The more CpGs available, the greater the epigenetic potential. In invasive species, genetic variation has been observed to be paradoxical: not much of it exists on a genomic level, but epigenetically, phenotypic variation can occur. The focus on shift in gene expression in this study is on Toll-Like Receptor 4 …

Amblyomma Quadricavum (Schulze, 1941) (Acari:Ixodidae): First Description Of The Nymphal Stage And Phylogenetic Assessment Of Its Taxonomic Status, Ashleigh V. Riggs

Electronic Theses and Dissertations

The hard tick (Acari: Ixodidae) Amblyomma quadricavum (Schulze, 1941) is a parasite of snakes and is endemic to the Caribbean region. Morphological characters of this species, namely its rudimentary eye structures, have led to debate about its taxonomic status. The species was originally assigned to the genus Aponomma. However, with revisions of the genus Aponomma, and the recent creation of new genera created for some basal former-Aponomma, it has been suggested that perhaps Amblyomma quadricavum might be a close relative of Robertsicus elaphensis, the Trans-Pecos rat snake tick of the southwest United States and New Mexico, another eyeless former-Aponomma species …

The Influence Of Autism Linked Gene Topoisomerase 3b (Top3b) On Neural Development In Zebrafish, Sydney Doolittle

Honors College Theses

Autism Spectrum Disorder is a class of developmental disabilities characterized by a spectrum of social, communication, and behavioral impairments in affected individuals. Studies have shown these defects stem from abnormal brain development during critical periods during early development. The underlying genetic cause of these impairments is not well understood but is believed to be a combination of a complex pairing of genetic and environmental factors. One of the genetic factors that has been recognized to influence the phenotypic symptoms of ASD is the enzyme topoisomerase 3β (top3β.) Topoisomerases are responsible for the prevention of supercoiling during DNA replication. Top3β is …

Disease Prevalence And The Population Genetic Structure Of Crassostrea Virginica Along The Georgia Coast, Sarah Batchelor

Electronic Theses and Dissertations

The Eastern Oyster, Crassostrea virginica, is an ecologically important species that plays a role in protecting shorelines, water filtration, and providing habitat and food for various fish species. Perkinsus marinus and Haplosporidium nesloni are two pathogens currently affecting oyster populations. These pathogens have both been documented as causes of mass mortality events along the East coast. They greatly diminish the health of oysters, resulting in the degradation of oyster tissue, reduction in growth and reproductive ability, and may cause death. In this study, wild oysters were collected from eleven locations along the Georgia coast to investigate the presence, intensity, …

Molecular Survey Of Helminths Infecting Ground Dwelling Birds In The Grouse Subfamily Tetraoninae, Briana M. Sesmundo

Honors College Theses

Alaskan grouse and ptarmigan (Galliformes) are important avian game species in Alaska. Interestingly, gallids harbor a fairly diverse helminth fauna, particularly cestodes, which may make birds with high parasite loads more susceptible to predation. Unfortunately, there is limited information available on the helminth fauna of Alaskan gallids, and no molecular surveys. The present study aims to develop baseline data on diversity of intestinal and subcutaneous (filariid) helminth infections in galliforms using morphological and molecular (DNA) approaches. These data can then be used to better understand changes in helminth community structure given current environmental volatility. The intestines, cloaca, liver and kidneys …

Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer

Electronic Theses and Dissertations

The intestinal microbiome of mammals plays a significant role in host health and response to environmental stimuli and can include both beneficial native bacteria as well as parasitic worms. In this study, I examined the intestinal cestode and bacterial communities of two closely related species of shrew, Sorex monticola and Sorex cinereus, over a six month period in 2016. Specimens were collected approximately every three weeks from May to October from the Sangre de Cristo Mountains in Cowles, New Mexico. A total of 79 shrews were prepared with the gastrointestinal tracts removed and flash-frozen in liquid nitrogen. An additional …

Analysis Of Genes Encoded By A Chromosomal Insert In Rickettsia Philipii, Sydney A. Wright

Honors College Theses

Background: Spotted Fever group rickettsiae are obligate intracellular arthropod-borne bacteria. Rickettsiae are globally distributed yet typically confined to the distribution of their vector(s). Rickettsia rickettsii and Rickettsia philipii are closely related human pathogens endemic to the United States and cause similar febrile illness with differing morbidity and mortality. Genomic comparison found the presence of a 19 kilobase insert containing eleven genes in Rickettsia philipii. The functions of proteins encoded by this insert are speculated to affect virulence and pathogenicity.

Materials and Methods: Bioinformatic analysis was performed to identify functional motifs in four proteins encoded by the insert. Homologous proteins …

Evolutionary Linkage Of Mimetic And Non-Mimetic Color Traits In A Coral Snake Mimicry Complex, John D. Curlis Jr

Electronic Theses and Dissertations

Color polymorphism in aposematic mimicry systems is a perplexing phenomenon for evolutionary biologists, as theoretically the benefits of converging on a model phenotype should constrain the evolution of phenotypic diversity in these systems (i.e., color polymorphism should not occur). Nevertheless, color polymorphism in mimicry systems is prevalent throughout many taxa. In some of these systems, the evolution of color polymorphism results in the existence of non-mimetic morphs, such as those that are cryptic. The case of ground snakes (Sonora semiannulata) is unique in that color polymorphism encompasses both mimetic and cryptic morphs, as well as individual mimetic and …

Determining The Reproductive Patterns Of The Titan Acorn Barnacle (Megabalanus Coccopoma) In Its Introduced Range, Isabel L. Moran Ms.

Honors College Theses

Invasive species are a significant conservation concern given their contribution to native species decline. The barnacle, Megabalanus coccopoma, is a common invasive species in tropical and subtropical regions of both the Pacific and Atlantic oceans. Little is known about the life history and ecology of M. coccopoma, and data on reproductive biology could provide valuable insight into its propensity to establish introduced populations. Most species of barnacle (including M. coccopoma) are hermaphroditic, but self-fertilization is rare in species studied to date. A recent genetic study of introduced M. coccopoma populations in the southeastern US showed high levels of …

Biogeographical Patterns In The Hard-Tick Genus Amblyomma Koch 1844 (Acari: Ixodidae), Matthew H. Seabolt

Electronic Theses and Dissertations

Amblyomma Koch is a genus of hard-ticks with approximately 130 species. Its geographical range is typical for organisms with a Gondwanan origin. A majority of these species are endemic to the Neo- and Afrotropical regions, with the remaining taxa dispersed throughout Southeast Asia, Australia and the Pacific islands. Based on this distribution, we hypothesize that the genus dispersal patterns will mirror the fragmentation and continental drift of the Gondwanan supercontinent. Maximum parsimony, maximum likelihood, Bayesian inference and node-dating analyses of nuclear 18S rDNA gene sequences reveal a more recent origin and radiation patterns within the genus and suggest that Amblyomma …

The Behavioral, Biochemical And Genetic Effects Of Sleep Deprivation In Zebrafish (Danio Rerio), Jade Catherine Boykin

Electronic Theses and Dissertations

Vertebrate sleep is a universal phenomenon and encompasses an array of conserved behavioral and physiological characteristics. Studies of sleep in humans have shown that sleep deprivation leads to adverse effects to human health and additional stress. Teleosts have emerged as a useful model species to study the vertebrate stress response, given its stress axis has high levels of homology with the mammals, including humans. For this study, the behavior of zebrafish (Danio rerio) subjected to acute (24 hours) and chronic (20 days) extended light exposure was monitored and whole-body cortisol was analyzed as an indication of activation of …

Determination Of The Dermacentor Variabilis Ferritin Gene Exon And Intron Structure, Dana Sylvestre

Honors College Theses

The American dog tick Dermacentor variabilis is a hard body, 3-host tick that relies on the blood of small and large mammals to satisfy its metabolic demands. The excess iron consumed in its blood diet can cause cellular damage through oxidation. Ticks rely on the ferritin protein to metabolize iron. For this reason, it is important to further characterize the ferritin gene. After extracting DNA from D. variabilis ticks, the suspected ferritin gene was amplified through polymerase chain reaction (PCR) and purified. The putative ferritin DNA fragment was inserted into plasmids and isolated in a long PCR length gene cloning. …

Relative Abundances Of The Recently Introduced Barnacles, Megabalanus Coccopoma And An Unidentified Species Of Megabalanus, In The Southeastern U.S., Jennifer L. Tyson

Honors College Theses

ABSTRACT

Megabalanus coccopoma is a prominent invasive species off the coast of Georgia. Recently, among collected samples thought to be M. coccopoma, several individuals of an unidentified species of barnacle were found. The species has been identified as a Megabalanus species, but is still unidentified to the species level. Species identification is difficult due to morphological variation, inconsistent taxonomic keys, and unknown origin. In this study I developed a method to accurately distinguish M. coccopoma from the unidentified Megabalanus sp. using sequence differences in the mitochondrial Cytochrome Oxidase I (COI) gene. This study will provide an accurate estimate of …

The Role Of Artificial Structures In Facilitating Range Expansion Of The Introduced Barnacle Megabalanus Coccopoma In The Southeastern U.S.A., Alicia M. Reigel

Electronic Theses and Dissertations

The barnacle Megabalanus coccopoma is a recent invader of the southeastern U.S.A. from the tropical eastern Pacific. In Georgia, M. coccopoma populations along the immediate coastline often suffer extensive mortality during the winter, but population rebuilding is common after these events suggesting that there may be nearby larval sources. I investigated the hypothesis that artificial structures (i.e., buoys, towers), occurring far enough offshore of Georgia for water temperatures to be moderated by the Gulf Stream, provide refuges for breeding adults of M. coccopoma and can serve as the larval source. I investigated this hypothesis by first developing thirteen microsatellite primer …

Helping To Resolve Taxonomic Conflicts Within The Genus Amblyomma (Acari:Ixodidae) From A Molecular Perspective, Paula Lado

Electronic Theses and Dissertations

This work sought to reassess the taxonomic status of Amblyomma parvum Aragao, 1908 and of the A. maculatum group of ticks Camicas, 1998. By using different molecular markers, 12SrDNA, 16SrDNA, DL, COI, COII (mitochondrial) and ITS2 (nuclear), I analyzed the systematic relationships between these taxa and their closest relatives. Phylogenetic analyses by maximum parsimony, maximum likelihood, and Bayesian analysis were performed in order to determine relationships among species and populations, and to determine the evolutionary history of these ixodids. The data obtained supported the hypothesis of cryptic speciation occurring within A. parvum, with the northern populations of Central America being …

A Morphological And Genetic Analysis Of Forensically Important Blow Flies, From Georgia: The Genus Lucilia, Katie S. Googe

Honors College Theses

Identification of Blow flies (Diptera: Calliphoridae) to species is important for estimating postmortem intervals, because insect species develop at different rates. Three Blow fly species in Georgia; Lucilia coeruleiviridis, L. cuprina, and L. sericata are similar morphologically, making identification difficult. Furthermore, the status of L. cuprina is in doubt; this species may be a complex of true L. cuprina, and L. cuprina x L. sericata hybrids. The objective of this study was to survey the Georgia Blow fly community and validate the statuses of L. coeruleiviridis, L. cuprina, and L. sericata, through morphological and …

The Prevalence And Effect Of Wolbachia Infection On The Brown Widow Spider (Latrodectus Geometricus), Brittany Dane' Arrington

Electronic Theses and Dissertations

Wolbachia was recently identified in the Brown Widow Spider (Latrodectus geometricus). This symbiont has not previously been found in this genus, therefore the consequences on the host’s population dynamics are unknown. The frequency of endosymbiont infection can provide insight into the population dynamics of the host as this bacteria is known to alter host life history. In my 1^st chapter I determine the prevalence of Wolbachia pipentis infection in in the Brown Widow Spider (Latrodectus geometricus) from five locations in the Southeastern United States. Infection frequency differed significantly among sampling locations, ranging from 20% to …

Soil Microbial Community Distributions And Disease Suppressiveness In The Coastal Plain Of Georgia, Michael J. Sabula

Electronic Theses and Dissertations

This study compared the soil microbial communities of three vegetation types in the coastal plain of Georgia: 1. crop land actively in use for agricultural production, 2. transitional grassland in early stages of secondary succession, and 3. pristine unmanaged forest land. Microbial species diversity and quantities of microbial DNA were determined from each of these vegetation types at three separate locations near Statesboro, Georgia. Length heterogeneity PCR(LH-PCR) methods and subsequent analysis of fungal, bacterial, and metazoan communities by analysis of similarity (ANOSIM) revealed high within-group similarity by vegetation type, indicating land management intensity and vegetation cover is a strong determining …

The Tick Genus Amblyomma In Africa: Phylogeny And Mutilocus Dna Barcoding, Omobolanle Kushimo

Electronic Theses and Dissertations

The tick genus Amblyomma includes approximately 130 species, 28 of which are found on the African continent and/ or in Madagascar. In order to understand the evolutionary phylogeography of the genus, it is necessary to gain a better understanding of the relationships between African taxa. Therefore, the main goals of this work were to, (1) reconstruct the phylogenetic relationships of the African Amblyomma available to us and (2) test markers for their usefulness as barcoding tools to link unknown immature specimens to their corresponding adults. The mitochondrial gene markers used in this study (12SrDNA and COI) did not resolve the …