Life Sciences Commons^™

Effects Of Melatonin On Heartbeat And Possible Identification Of A Melatonin Receptor In Drosophila Melanogaster, Tricia L. Vankirk

Electronic Theses and Dissertations

Chapter 1 of this manuscript is a literature review that serves as an introduction to the entire dissertation. Chapter 2 examines the effects of the melatonin injection on heart rate and rhythmicity in Drosophila melanogaster Canton-S (wild-type) pupae and pupae bearing a variety of heart mutations. Chapter 3 investigates further the possible mechanisms of melatonin’s ability to increase heart rhythmicity without significantly affecting heart rate. A melatonin antagonist, luzindole; a high-affinity melatonin agonist, 2-iodomelatonin and RNAi techniques are used to identify a possible melatonin receptor in Drosophila melanogaster.

An appendix contains a previously published manuscript detailing experiments performed at the …

Atmospheric Nitrogen Assimilation In Ustilago Maydis., Michael Cooper

Electronic Theses and Dissertations

Nitrogen is an essential nutrient for all living creatures. Ammonium is one of the most efficiently used and thus preferred, sources of nitrogen. As with other dimorphic fungi, yeast-like cells of Ustilago maydis, a fungal pathogen of maize, switches to filamentous growth when starved for nitrogen/ammonium. U. maydis carries two genes, ump1 and ump2, encoding ammonium transporters that facilitate both uptake of ammonium and the filamentous response to its absence. While no obvious phenotype is observed when ump1 is deleted, cells without ump2 are unable to filament in response to low ammonium, although they can still grow. Surprisingly, …

Genetic Structure Of Ixodes Scapularis Say 1821 (Acari: Ixodidae), The Blacklegged Tick, By Microsatellite Analysis, John Ludwig

Electronic Theses and Dissertations

The blacklegged tick, Ixodes scapularis (Acari: Ixodidae) is the subject of intense research due to its economic importance from being a vector of several diseases. Previous studies have examined its taxonomic status and more recently, its genetic structure. This study embarked upon resolving the questions surrounding the genetic structuring of the tick, by using different molecular markers. Molecular data were first phylogenetically analyzed by using four different mitochondrial and nuclear markers (12SrDNA n=483, Dloop n=432, ITS2 n=156, Actin n=117). A Bayesian tree was inferred from the concatenated mitochondrial dataset, whereas nuclear gene markers were found to be uninformative. Nine microsatellites …