Genetics

Cercopithecus ascanius is an African primate species encompassing five geographic types with unresolved taxonomy. Recent publications have analyzed C. ascanius genetic diversity and taxonomy; however, few publications have addressed the genetic diversity and phylogenetic relationships of C. ascanius from wild populations. My objectives for this thesis were to determine mtDNA diversity within the C. Ascanius species and investigate C. ascanius genetic structure. Results from this thesis support findings from previous studies wherein C. ascanius depicted high mitochondrial diversity and all C. ascanius subspecies form a monophyletic clade within the Cercopithecus genus. Analyzing additional samples of C. ascanius monkeys will strengthen molecular diversity estimation and clarify genetic structure within the C. ascanius lineage.

Finding novel compounds that affect neuronal or muscular function is of great interest, as they can serve as potential pharmacological agents for a variety of neurological disorders. For instance, conopeptides have been developed into powerful drugs like the painkiller PrialtTM. Most conopeptides, however, have yet to be characterized, revealing the need for a rapid and straightforward screening method. We have designed a novel bioassay, which allows for unbiased screening of biological activity of compounds in vivo against numerous molecular targets on a wide variety of neurons and muscles in a rapid and straightforward manner. For this, we paired nanoinjection of compounds with electrophysiological recordings from the Giant Fiber System of Drosophila melanogaster, which mediates the escape response of the fly.

Harman's theory of aging proposes that a buildup of damaging reactive oxygen species (ROS) is one of the primary causes of the deleterious symptoms attributed to aging. Cellular defenses in the form of antioxidants have evolved to combat ROS and reverse damage; one such group is the methionine sulfoxide reductases (Msr), which function to reduce oxidized methionine. MsrA reduces the S enantiomer of methionine sulfoxide, Met-S-(o), while MsrB reduces the R enantiomer, Met-R-(o). The focus of this study was to investigate how the absence of one or both forms of Msr affects locomotion in Drosophila using both traditional genetic mutants and more recently developed RNA interference (RNAi) strains. Results indicate that lack of MsrA does not affect locomotion. However, lack of MsrB drastically reduces rates of locomotion in all age classes. Furthermore, creation of an RNAi line capable of knocking down both MsrA and MsrB in progeny was completed.

Atrazine is a popular herbicide used in over 80 countries to inhibit the growth of broadleaf and grassy weeds. Atrazine is a common pollutant in soil and groundwater, and high concentrations of atrazine cause developmental defects in fish, amphibians, and birds. The bacteria Pseudomonas sp. strain ADP (P.ADP) uses atrazine as a nitrogen source by transforming atrazine to ammonia through a number of enzymatic reactions. In this project I measured the growth and atrazine degradation of P.ADP in media with atrazine as the sole nitrogen source. A mutant strain isolated after mutagenesis with UV light showed faster growth and reached higher densities than the control strain. A series of mating experiments were performed to determine whether the growth mutation was on the atrazine degrading plasmid or in the chromosome. The limitations and potential of P.ADP for atrazine degradation are discussed.