Life Sciences Commons^™

Evolution Of Caffeine Biosynthetic Enzymes And Pathways In Flowering Plants, Ruiqi Huang

Dissertations

Convergent evolution generally refers to the independent evolution of similar biological function more than once in unrelated species. Caffeine is thought to have evolved by convergence, and is naturally produced through secondary metabolism in plants to defend against pathogen attack and insect feeding or to attract pollinators. The same caffeine biosynthetic pathway has been elucidated in Camellia (tea) and Coffea (coffee), in which xanthosine is sequentially methylated to caffeine via 7-methylxanthine and theobromine. However, although the same catalysis pathway is used, different (paralogous) enzymes in the SAMT/BAMT/theobromine synthase (SABATH) multigene family are used in the two species. In my dissertation, …

Regulation Of Glial Cell Line-Derived Neurotrophic Factor (Gdnf) Production In Voluntary And Involuntary Muscle, John-Mary Vianney

Dissertations

Glia cell line-derived neurotrophic factor (GDNF) is a survival factor for subpopulations of neurons, including somatic and autonomic motor neurons. These neurons depend, in part, on GDNF that is synthesized and secreted by their target tissues. It has been shown that a number of tissues in the periphery express GDNF and these target tissues differ in their composition, function, and in the case of different muscle cell types, their contractile characteristics. Whether the processes regulating GDNF production in these different tissues is similar or different is poorly understood. The broad goal of this study is to examine factors that normally …

Exercise Alters Glial Cell Line-Derived Neurotrophic Factor (Gdnf) Protein Content In The Spinal Cord, Monica Janine Mccullough

Dissertations

Neurotrophic factors may play a role in exercise-induced neuroprotective effects; however, it is not known if exercise mediates changes in glial cell line-derived neurotrophic factor (GDNF) protein levels in the spinal cord. The aim of the studies described herein was to determine if exercise alters GDNF protein expression in the lumbar spinal cord of healthy and diseased animals. The lumbar spinal cord was analyzed from adult rats aged 6-, 12-, 18- and 24-months, and from transgenic amyotrophic lateral sclerosis (ALS) mice and wild-type mice aged 3 months. Animals had undergone either forced wheel running, voluntary wheel running or swimming for …

Exposure Of Nervous System Cells To Polychlorinated Biphenyls (Pcbs), Results In Alterations Of Neurotrophic Factor Expression, Gordon H. Gurley

Dissertations

Toxic insult by PCBs results in learning and memory deficits in humans. Alterations in expression of neurotrophic factors (NF) and/or their receptors have been linked to changes in learning and memory. How PCBs affect cognition is not known. We suggest that PCBs affect cognition by altering NF expression.

We exposed cultured C6 rat glioblastoma cells (an astrocyte cell-line) to medium containing PCB (Aroclor 1254 (10ppm)). Control cells were treated with dimethyl sulfoxide (DMSO) or regular medium. Enzyme-linked immunosorbent assays (ELISA) were used to determine glial cell-line derived neurotrophic factor(GDNF) and nerve growth factor (NGF) concentrations in all samples. We also …