Life Sciences Commons^™

Population Demographics And Genetic Structure Of Black Bears In Coastal Louisiana, Jesse Charles Troxler

Masters Theses

The range and abundance of the Louisiana black bear (Ursus americanus luteolus) were greatly diminished during the 20th century. This subspecies was reduced to 3 small, isolated subpopulations in Louisiana as bottomland hardwood habitat was converted to agriculture. These bears were listed as threatened by the U.S. Fish and Wildlife Service in 1992 and a recovery plan was published in 1995. Recovery requires estimates of population parameters to evaluate current population status and future viability. I conducted a mark-recapture study from 2010 to 2012 to estimate demographic parameters of the coastal population of Louisiana black bears. Because inbreeding …

Trends In Borrelia Spp. Prevalence In Ixodes Spp. Ticks From The Southeastern Coastal United States, Lauren Paul Maestas

Masters Theses

The Lyme borreliosis (LB) cycle, involving Ixodes scapularis and Borrelia burgdorferi sensu stricto (Bbss), is well documented in the northeastern US, where LB is becoming increasingly prevalent. In coastal North Carolina, I. affinis has been shown to have a higher incidence of Bbss than I. scapularis. My objectives were, to assess changes in prevalence of Bbss in Ixodes spp. along a transect from Virginia to Florida, and to assess the value of dogs and mesomammals as sentinels for spread of Borrelia burgdorferi sensu lato.

Ixodes spp. were collected at sites from 37.4^o N to 30.0^{o …}

Single-Nucleotide Polymorphisms Associated With Performance Traits In Beef Cattle Grazing Endophyte-Infected Tall Fescue, Bryan Christopher Bastin

Masters Theses

Tall fescue (Lolium arundinaceum Schreb.) is the most prevalent forage in the Midsouth United States due in part to the presence of the endophytic fungus Neotyphodium coenophialum. The fungus, while conferring hardiness to tall fescue, contributes to decreased production efficiency in cow-calf operations. A previous genome-wide association study was performed using the Illumina 50k bovine SNP chip. Twenty-four SNP were found to be associated (P < 0.05) with adjusted birth weight and adjusted 205-day weights of calves from 48 beef cows at Ames Plantation. The first objective was to validate each SNP by testing associations with several additional phenotypes. Custom Taqman genotyping assays (Applied Biosystems, Foster City, CA) were subsequently designed to genotype each SNP in beef cattle located at Tennessee Tech University (n = 654), to validate associations in a large, independent herd. The results yielded 15 associations that were significant (P < 0.05) with 6 phenotypes linked to those affected by fescue toxicosis. The second objective investigated the link between fescue toxicosis and the XK, Kell blood group complex subunit-related, member 4 …

Molecular Systematics Of The Subfamily Phasiinae (Diptera: Tachinidae), Jeremy Daniel Blaschke

Masters Theses

The subfamily Phasiinae (Diptera: Tachinidae) is composed of obligate endoparasitoid flies that attack heteropteran insects, many of which are important agricultural pests. To lay a foundation for future studies in phasiine life history and their potential for use as biological control agents, the phylogenetic relationships within Phasiinae were explored using nucleotide sequences of two genes, CAD and LGL. A total of 63 taxa for CAD and 73 taxa for LGL were included in the analyses, representing 58 genera. Maximum likelihood inference methods were employed to reconstruct phylogenetic relationships in separate analyses of each gene and in a combined dataset. Phylogenetic …

Microarray Analysis Of Mrna Translation State In Arabidopsis Thaliana, Bayu Sisay Tiruneh

Masters Theses

The synthesis of proteins – translation – is one of the cellular processes that consume a great deal of energy. Genome-wide assays performed in Arabidopsis and other organisms have revealed that the translation status of mRNAs responds dramatically to different stresses and environmental and growth signals. Similar assays have revealed how translation of specific mRNAs is perturbed by genetic mutations in eukaryotic translation initiation factors (eIFs). I performed genome-wide analyses of translation state in A. thaliana seedlings with mutant genotypes for a specific eIF (subunit h of eIF3) and the large ribosomal protein, L24 (RPL24B). Using data from prior microarray …

Genomic Analysis And Functional Characterization Of The Terpene Synthase Gene Family In Brachypodium Distachyon, Ayla Marie Norris

Masters Theses

Brachypodium distachyon is a small, temperate grass native to the Mediterranean region. While not agriculturally important, it possesses many characteristics such as rapid generation time, self-pollination, a small genome size, and ease of genetic transformation, that make it an attractive model organism for genetic studies. Brachypodium is closely related to other grasses of economical importance such as rice, sorghum, and especially wheat, and in fact it is the first member of the Pooideae grass sub-family to have its genome fully sequenced. Cereal grasses such as rice, sorghum, and maize have been reported to produce a class of secondary metabolites called …