http://digital.library.wisc.edu/1793/6665 http://minds.wisconsin.edu/retrieve/5653 http://digital.library.wisc.edu/1793/6665 Search the Channel search http://minds.wisconsin.edu/simple-search http://digital.library.wisc.edu/1793/8148 Title: The role of a soluble, competitive FGF receptor in embryonic stem cell-derived hematopoiesis <br/> <br/>Authors: Webster, Daniel E. <br/> <br/>Abstract: The fibroblast growth factor (FGF) signaling pathway plays a pivotal role in the maintenance of embryonic stem cells (ESCs) as well as their differentiation into the hematopoietic lineage. We observed that supplementing human and rhesus ESCs in embryoid body (EB) culture with the FGF-2 ligand showed a dose-dependent stimulation of hematopoietic differentiation. However, despite phylogenetic similarities, rhesus ESCs needed a 5-fold greater concentration of FGF-2 relative to human ESCs to achieve optimal hematopoiesis. To elucidate the mechanism behind this species-specific differential requirement for the central growth factor FGF-2, we measured and compared endogenous gene expression of FGF ligands and splice variant isoforms of FGF receptor 1 (FGFRI) between human and rhesus ESC lines. The results indicate that rather than an inherent lack of FGF ligand production in rhesus ESCs relative to human ESCs, there are significant differences in their expression of FGFRI isoforms. Our findings suggest that an increasing fraction of the soluble, competitive inhibitor sFGFRI isoform relative to the functional FGFRlα isoform expressed in ESC cultures correlates (r2=0.84) to a decrease in the degree of hematopoietic differentiation achieved by a differentiating ESC population. This finding not only offers an explanation for the observed differences between rhesus and human hematopoiesis, but also implies a mechanism by which developing cells can self-regulate hematopoietic induction by secretion of competitive, inhibitory receptor isoforms. <br/> <br/>Description: 17 p. http://digital.library.wisc.edu/1793/8146 Title: An investigation on the effects of mutations in the ATG12 autophagy pathway of Arabidopsis thaliana <br/> <br/>Authors: Damodaran, Ashvini <br/> <br/>Abstract: Under nutrient-deficient conditions, plants are forced to recycle secondary cellular constituents to conserve energy for the more essential processes (Klionsky, et al. 2000). Plants accomplish this through a process called autophagy, which involves the capture of cytosolic constituents in vesicles called autophagosomes and transportation of these vesicles to lytic vacuoles for degradation. Macroautophagy, the main autophagy pathway, requires an ATGI2-ATG5 protein conjugate for autophagosome formation (Thompson & Vierstra, 2005). Extensive research has been done on the ATG 12 pathway in organisms such as yeast, but research is yet to be done on ATG12 disruption in plants. By studying protein expression and performing phenotypic analysis oft he model plant Arabidopsis thaliana with mutationsinATG12and other members ofthe ATG12 pathway, we can begin to understand the role of the pathway in autophagic recycling during plant growth and development. Since autophagy controls many important aspects of crop physiology (e.g. seed germination, pathogen defense, and growth under nutrient-limiting conditions), this work will likely provide new venues for improving crop production. <br/> <br/>Description: 21 p. http://digital.library.wisc.edu/1793/8142 Title: Starvation responses of invasive and non-invasive Eurytemora affinis populations <br/> <br/>Authors: Chau, Fong Ching <br/> <br/>Abstract: Within the past century, the copepod Eurytemora affinis have invaded freshwater from saline sources throughout the Northern Hemisphere. Two genetically divergent clades (Atlantic and North Atlantic) of E. affinis coexist in the St. Lawrence estuary, but only the Atlantic clade was able to invade into freshwater ecosystem. A common-garden reaction norm experiment was performed on populations from these two clades to determine their differences in survival and development time across three food levels (high, medium and low) in fresh water. The populations were fed with the freshwater alga Rhodomonas minuta. The developmental progress and survival of the populations were monitored throughout the experiment. The results indicated that the population from the invasive Atlantic clade is more starvation resistant and has faster development time to adulthood. The differences between the populations might be due to their different osmoregulatory mechanisms and energy usages. These different physiological responses to starvation are likely to have functional consequences for the populations' ability to expand their ranges into novel environments. <br/> <br/>Description: 24 p. http://digital.library.wisc.edu/1793/7987 Title: To determine the functional relevance of circadian Fabp7 expression in memory consolidation <br/> <br/>Authors: Lai, Tsz Chung <br/> <br/>Abstract: Fatty-acid binding protein 7 (Fabp7) is closely related to sleep/wake cycle and regulated in a circadian pattern. To investigate whether the expression affects learning and memory behavior, we used the Drosophila model. Transgenic lines of FABP7 were conditionally expressed in order to test the hypotheses that FABP7 altered the formation of long-term memory (LTM). Unlike the circadian rhythm, much less has been known for the behavioral state and the homeostatic regulation of sleep control at the molecular and genetic levels. Previous results show that all synapses are affected in a similar manner, and the molecules that have a diurnal pattern of expression at synapses throughout the brain after sleep/wake cycle would be excellent candidates for cellular correlates responsible for the homeostatic arm of sleep regulation, and they are also targets of therapeutic approaches to neurological diseases. Therefore, identifying and investigating the targeted synaptic molecules involved in the sleep/wake rhythm is important for a better understanding of mental illness. <br/> <br/>Description: 1 p. 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