Thesis (Ph. D.)--University of Chicago. / "Zool. jahrb. XXI. Abt. f. anat." Bibliography: p. 418-424.

Thesis (Ph. D.)--University of Chicago. / "Zool. jahrb. XXI. Abt. f. anat." Bibliography: p. 418-424. Also available on the Internet. Also issued online.

Thesis (Ph. D.)--Johns Hopkins University, 1914. / Vita. "Reprinted from the Journal of Experimental Zoology, vol. 19, no. 2. August, 1915." "Literature cited": p. 205-207.

Heidelberg, Univ., Diss., 2004. / Computerdatei im Fernzugriff.

Darmstadt, Techn. Universiẗat, Diss., 2003. / Dateien im PDF-Format.

Heidelberg, University, Diss., 2004.

Hydra is a simple freshwater solitary polyp used as a model system to study evolutionary aspects. The immune response of this organism has not been studied extensively and the immune response genes have not been identified and characterized. On the other hand, immune response has been investigated and genetic analysis has been initiated in other lower invertebrates. In the present study we took initiative to study the self/nonself recognition in hydra and its relation to the immune response. Moreover, performing phylogenetic analysis to look for annotated immune genes in hydra gave us a potential to analyze the expression of minor histocompatibility genes that have been shown to play a major role in grafting and transplantation in mammals. Here we obtained the cDNA library that shows expression of minor histocompatibility genes and confirmed that the annotated sequences in databases are actually present. In addition, grafting experiments suggested, although still preliminary, that homograft showed less rejection response than in heterograft. Involvement of possible minor histocompatibility gene orthologous in immune response was examined by qPCR.

The role of L-Lactate has expanded from an energy metabolite to a signaling molecule in neurons. Studies have shown that L-Lactate plays a role in neuroprotection and in NMDAR-dependent long-term memory formation. The aim of this dissertation is to characterize the role of L-Lactate as a signaling molecule and understand the molecular mechanism through which L-Lactate potentiates NMDAR signal. Using mass spectrometry, I monitored the time-dependent changes in the phosphoproteome of cortical neuronal cultures in response to Lactate. The phosphoproteomic analysis highlighted a number of cytoskeletal proteins involved in synapse remodeling as well as axon guidance that were regulated by L-Lactate. In addition, I found that L-Lactate induced phosphorylation of proteins involved in the MAPK pathway, as reported in an earlier study. I hypothesize the involvement of CaMKII in this mechanism. CaMKII is one of the most abundant kinases in the brain and plays a role in learning and memory via interaction with NMDAR. Using CaMKII inhibitors and mutants of the NMDAR subunit GluN2B, the findings in this dissertation provide evidence for the involvement of CaMKII, specifically, the interaction between CaMKIIa and GluN2B, as a requirement for the L-Lactate mediated potentiation of NMDAR signal. In addition, to gain insight into the evolution of lactate from a metabolite to a signaling molecule, this study explores the evolution of glutamate as a signaling molecule in multicellular organisms so it may serve as a model for evolution of metabolites like lactate into signaling molecules. For this purpose, the model organism Hydra was used, since it belongs to phylum Cnidaria, evolutionarily one of the first phyla to have a nervous system. In order to explore whether glutamate receptors, particularly, NMDAR are functionally expressed in Hydra and are localized in neurons, a line of transgenic Hydra expressing a calcium indicator (GCaMP6s) in neurons was generated. With the transgenic Hydra line, I attempted to measure the in vivo response of neurons in Hydra to glutamate. This study highlights several ground work experiments with an extensive discussion of implications and challenges and an outlook for future investigations.

No description available.

Harmony Landfill is a former industrial waste disposal site located adjacent to Harmony Creek in Oshawa, Ontario, Canada. During active disposal, from 1957 until 1980, approximately 1 million tonnes of waste were land-filled at the site. Although past environmental monitoring had indicated localized contamination of ground and surface waters, the current level of impact remained unclear. In order to determine the potential of Harmony Landfill leachate to affect aquatic organisms in Harmony Creek, chemical analysis of field samples and laboratory toxicity testing were performed. Chemical analysis was completed on water samples from Harmony Creek and surface leachate samples collected seasonally at Harmony Landfill. Toxicity tests were conducted using the model freshwater invertebrate Green Hydra (Hydra viridissima). Hydra were pulse-exposed for 24 hours to varying concentrations (0%, 3.2%, 10%, 32%, 100%) of monthly field-collected leachate samples diluted with laboratory water. Population growth, Hydra morphology and survival were recorded daily for 7 days. Results showed that creek waters generally had comparable analyte levels upstream and downstream of Harmony Landfill. Leachate samples contained iron, manganese and zinc at levels which may be toxic to aquatic invertebrates. Population growth was significantly inhibited compared to lab water (0%) controls at the 100% leachate concentration in December 2008 and July 2009. Hydra morphology (32% and 100%) and survival (100%) were also affected by the December 2008 leachate. Findings indicate that leaching is occurring at Harmony Landfill and that the leachate sampled and tested during this research program had the potential to negatively affect Green Hydra (Hydra viridissima). / UOIT