Life Sciences Commons^™

Genetic Diversity Of Kemp's Ridley (Lepidochelys Kempii) Sea Turtles On South Padre Island, Texas, Hilary R. Frandsen

Theses and Dissertations

In 2010, researchers observed an abrupt decline in nesting numbers of the Kemp’s ridley following 35 years of positive growth. In wake of this halt, and subsequent lowered nesting averages, evaluation of the genetic diversity of remaining individuals is relevant to investigate the plausibility of a genetic bottleneck, and determine the reproductive stability of the Kemp’s ridley.

Here, I evaluate the genetic diversity within a sampling of the Kemp’s ridleys on South Padre Island using two methods: targeting the mitochondrial control region and targeting the complete mitochondrial genome. Opportunistic samples were donated from juvenile ridleys on the East coast, and …

Reevaluating The Occurrence And Phylogeny Of The Pigtoe Unionid Mussels Fusconaia Askewi, Fusconaia Lananensis, Fusconaia Flava, And Pleurobema Riddelli In Texas, Charles J. Pratt

Biology Theses

The recent development of DNA-based species classification methods has led to the revision of many morphology-based species designations as genetic data has provided new information for species delineation. Analysis of standardized DNA ‘barcoding’ gene regions has proven particularly effective in resolving the taxonomic status of taxa that display phenotypic and habitat overlap.

Freshwater Unionid and Margaritiferid mussels comprise one of the most diverse aquatic taxa in North America, but are also among the most threatened, with over 70% of the approximately 300 native species considered at-risk or in decline. Although mussels face extensive threats from anthropogenic activity, conservation efforts have …

Isolation And Comparative Genomic Analysis Of Final Third Of Satis Genome, Kelly Hartigan, Nicole Curnutt, Matthew Mcdermut

Undergraduate Research Symposium Posters

A highly novel Streptomyces phage, Satis, was isolated from a direct environmental sample collected from outside Danforth House on the Washington University campus. Satis infects bacterial species Streptomyces lividans producing pinpoint, cloudy plaques less than 1mm in diameter. Electron microscope data shows rare atypical physical features. Rather than the common octahedral capsid shape, Satis has a prolate head with visible cross-linked hexagonal protein structure and average measurements of 285 nm by 47 nm with a long, flexible tail measuring 268 nm. Upon sequencing, it was found that Satis contains the longest phage genome discovered to date through the SEA-PHAGE program …

Effective Population Size, Demography, And Viability Of Eastern Massasaugas (Sistrurus Catenatus) In Southwest Michigan, Danielle R. Bradke

Masters Theses

As humans increasingly exploit natural areas, wildlife populations face a growing number of threats that often result in population decline and isolation. Small, isolated populations are vulnerable to extirpation due to both genetic and demographic factors. Yet, low detectability of many imperiled species often precludes the collection of population-level data important for assessing population viability and implementing successful conservation. The eastern massasauga (Sistrurus catenatus) is a cryptic pitviper that has been extirpated throughout much of its historic range due to agricultural conversion of wetland habitat and other synergistic threats. Consequently, this species is federally listed as threatened in both the …

Post-Transcriptional Regulation Of The Drosophila Anterior Determinant, Bicoid, John Mclaughlin

Dissertations, Theses, and Capstone Projects

In a wide variety of biological contexts, messenger RNA (mRNA) is known to have a complex and dynamic life cycle. In particular, the localization and translational control of mRNA are essential for proper development in eukaryotes. The fly Drosophila melanogaster is an excellent model for studying these processes. During D. melanogaster oogenesis, several mRNAs are trafficked and localized within the developing egg chamber, and regulated at the translational level to enable embryo patterning. One such mRNA, bicoid, is localized at the anterior of the oocyte and translated in the early embryo, where its encoded protein directs formation of the fly's …

Studies On Development In Euphilomedes Ostracods: Embryology, Nervous System Development, And The Genetics Of Sexually Dimorphic Eye Development, Kristina Koyama

University of the Pacific Theses and Dissertations

Model organism studies have been fundamental in understanding evolutionary and developmental biology. However, non-model organisms present opportunities to study unique characteristics and as comparisons to model organisms, leading us toward broader and more relevant perspectives on diversity. The Euphilomedes genus of ostracods is an example of a non-model group with potential for evolutionary and developmental studies.

Ostracoda is an ancient, basally branching lineage of Crustaceans with a complete and prodigious fossil record. Despite the group’s promise for evolutionary studies, much remains unknown about the basic biology of this clade. There are a limited number of embryogenesis studies in Ostracoda; here, …