41) Jennifer Weekes, Molecular BIology & Genetics/Andrew Waskiewicz, M. Sc., poster
Abstract Title: The role of BMP inhibitors in zebrafish eye development
Eye development is a dynamic process that requires the spatially restricted expression of signaling molecules to coordinate the establishment of dorsoventral and nasotemporal axes of the eye while morphogenetic movements shape the eye. Dorsally restricted bone morphogenetic protein (BMP) signaling is necessary for dorsal retinal patterning; alterations to BMP signaling result in aberrant dorsoventral patterning and improper closure of the ventral choroid fissure. The ventral eye defects that occur with aberrant dorsoventral patterning suggest that dorsalizing and ventralizing signals must be balanced for proper patterning and structure; however, signaling molecules involved in ventral eye specification have not been identified. By using zebrafish as a model for eye patterning and morphogenesis, we have identified three candidate genes for ventral eye patterning: smoc1, smoc2, and gremlin2, all of which are BMP inhibitors expressed in the ventral eye or surrounding tissues. Morpholino-mediated knockdown of gremlin2 suggests that gremlin2 contributes to the shape of the eye by acting as an anti-apoptotic factor in migrating neural crest and cells surrounding the eye. We are currently using transcription activator like effector nucleases (TALENs) to generate mutants by targeting the BMP binding domains of smoc1, smoc2, and gremlin2. Analysis of these mutants will allow us to elucidate the role that inhibition of BMP signaling has during early zebrafish eye development.
42) Patrick O. Welsh, Ecology/Keith Tierney and Cindy Paszkowski, M.Sc., Oral
Abstract Title: Implications of a wastewater sub-lethal toxicity experiment on mallard (Anas platyrhynchos) overwintering ecology in Edmonton, Alberta
Wastewater treatment plants (WWTPs) provide novel winter habitat for waterfowl by creating areas of warm, open water that can have potential fitness costs associated with their occupation. To assess the toxicological risk associated with ingesting wastewater, we exposed 2d old ducklings (Anas platyrhynchos) to municipal tap water (control), secondary clarified effluent water (SCEW), or 1µg/L 17α-ethinylestradiol (EE2; positive control) daily for 28d. Birds were gavaged (10mL/kg) and weighed daily, with blood taken once per week. After 28d, the mallards were sacrificed, and the weights of liver, spleen, and heart were taken, along with tarsal, wing chord, phallus, and beak lengths. SCEW exposure was associated with small increases in beak and chord lengths (4.3% and 7.4%, respectively), while EE2 exposed birds exhibited increases in beak, chord, tarsus, and phallus lengths (3.7%, 11%, 3.5%, and 11%, respectively), compared to controls. These increases likely resulted from stimulation of chondrocytes by estrogenic compounds. By using controlled, developmental exposures, we show that the small increases exhibited by ducklings are unlikely to be found in adult mallards wintering at Edmonton’s Gold Bar WWTP. While SCEW is unlikely to pose a health risk to mallards at Gold Bar, winter conditions may contribute to an ecological trap scenario.
43) Grace Carscallen, Maya Evenden, continued 399 project and poster.
Abstract Title: Control of larval Pseudaletia unipuncta (Lepidoptera: Noctuidae) with the insecticide chlorantraniliprole (DPX-E2Y45)
The true armyworm, Pseudaletia unipuncta (Lepidoptera: Noctuidae), is a widespread agricultural pest which can cause significant damage to cereal crops. The insecticide chlorantraniliprole (DPX-E2Y45), developed from the plant defense toxin ryania, is effective against several agricultural pests. This study aims to determine the efficacy of chlorantraniliprole against P. unipuncta larvae compared to a positive (Cruiser® insecticide) and untreated control. Laboratory feeding bioassays were conducted with P. unipuncta larvae on corn plants grown from seed treated with different concentrations of chlorantraniliprole and Cruiser®. In order to determine the insecticide efficacy at different larval stages and plant sizes, third instar larvae were placed on corn plants at the three and five–leaf stage in two separate experiments. For another experiment, fifth instar larvae were placed on five–leafed plants. Larval growth and mortality on the treated plants was monitored using head capsule measurements and clip cages. Insecticide efficacy was reduced when fifth instar larvae fed upon plants were in the five-leaf stage compared to both other experiments performed with third instar larvae.
44) abstract withdrawn
45) Tonia Cappellano, David Pilgrim, 299, poster presentation
Abstract Title: The role of the unc-119 gene in neuronal guidance in Caenorhabditis elegans
Understanding the structure and function of the nervous system is a major challenge in modern biology, yet the overwhelming complexity of the human nervous system makes the challenge almost unsurmountable. One approach is to use the advantages provided by simpler model animal systems to begin to tackle the basic tenants of the problem. The genetically and cellularly tractable nematode C. elegans have been found to display an uncoordinated phenotype when a mutation is present in the unc-119 gene, due to a widespread disruption in the patterning of the nervous system. The product of the unc-119 gene is structurally and functionally conserved with mammals, and we are interested in testing the hypothesis that UNC-119 functions in a pathway that controls neuronal guidance. Using different GFP markers that label neuronal cell bodies, axons, and commissures, I will catalogue the cellular defects seen when the unc-119 gene is mutated, either via null or missense alleles to try to determine the primary cellular defect leading to the mispatterned nervous system. Additional comparisons to genetic revertants and transgenic worms carrying targeted mutations in different domains of the UNC-119 protein will provide us with the relative importance of specific amino acids in the gene.
46) Joleen Khey, Microbiology and Biotechnology/Case, 499, Poster
Abstract Title: The effect of indole-3-acetic acid on microalgae growth
Microalgae are unicellular marine and freshwater organisms that have many industrial applications, including biofuels, aquaculture, fertilizers, and pharmaceuticals. One potential method to stimulate microalgae growth for the industrial and commercial cultivation is the addition of indole-3-acetic acid (IAA). IAA is a plant hormone involved in the regulation of many growth and developmental processes in terrestrial plants. Since IAA has a stimulatory growth effect on plants, a paralleled effect on microalgae is expected. Literature on the influence of IAA on algae is contradictory and fails to provide a cohesive conclusion. Furthermore, no standard methodology which successfully tests the effect of IAA on algae currently exists. The aims of this study are twofold: (1) develop a standard methodology to test the effect of IAA on algae, and (2) measure its effect in terms of algae cell division rate and photosynthetic capacity. I have developed a methodology for standardized testing of the effect of IAA on algae in stationary phase. Preliminary results indicate that lower concentrations of IAA has an effect on the chlorophyte Dunaliella over a short time period.
7) Denise Whitford, Microbiology/George Owttrim, M.Sc., Oral Presentation
Abstract Title: Localization of an RNA helicase to multiple subcellular compartments in a cyanobacterium
RNA helicases unwind, anneal and rearrange RNA secondary structures, frequently as part of a multisubunit complex. CrhR, the only DEAD-box helicase encoded in the cyanobacterium, Synechocystis sp. PCC 6803, genome is expressed at a basal level during normal cell growth and at an enhanced level when exposed to abiotic stresses, such as low temperature. Although many prokaryotic RNA helicases have recently been shown to have roles in ribosome biogenesis and assembly or the RNA degradosome, the cellular role of CrhR is unknown. Recent evidence suggests that CrhR may have multiple cellular roles, as it self-regulates its expression at a number of levels (Rosana et al., 2012). Here we report that CrhR localizes to different cellular compartments with soluble and membrane-associated forms existing at all temperatures. The soluble form co-sediments with the polysome while the membrane form specifically localizes to the thylakoid membrane. The interplay between these two compartments is under investigation. Developing a greater understanding of the localization of CrhR to these intracellular structures will advance our understanding of how this helicase functions in the temperature regulation of gene expression.
48) Lindsay Canham, Genetics/John Locke, MSc, Oral Presentation
Abstract Title: Characterization of a novel Drosophila kinase gene.
DNA is packaged into two states; euchromatin and heterochromatin, and histone modification maintains equilibrium between the two. The Drosophila melanogaster gene CG8878 was initially identified as a novel heterochromatin modifying protein from an enhancer of variegation mutant screen. Its amino acid sequence suggests it acts as a putative kinase. As part of the initial characterization, it was found that the predicted kinase domain sequence is interrupted. Molecular structure prediction shows that this interruption should not affect kinase enzyme function. My phylogenetic analysis places CG8878 in the Casein Kinase 1 family of protein kinases, however this gene group is limited to only insects. The CG8878 amino acid sequence shares sequence similarity in the kinase domain to the histone kinase ballchen, the Drosophila homolog of vertebrate Vaccinia related kinase. This similarity provides a starting point for comparative analysis of future protein function. Initial developmental timing experiments show that few homozygous mutant larvae survive up to pupariation. Future experiments hope to confirm kinase activity, identify cellular localization throughout the cell cycle, and confirm sites of phosphorylation using ballchen as a model gene.
49) Alyssa Weinrauch, Physiology, Cell and Developmental Biology, Greg Goss, M.Sc, oral presentation
Abstract Title: Intestinal Morphology and Transport Physiology of the Pacific Hagfish
The basal position of vertebrate phylogeny is occupied by the agnathans, hagfish and lamprey. Their primitive anatomy enables evolutionary studies however, the relationship between the two remains unclear with molecular data supporting monophyly and morphological data supporting paraphyly. A rigorous study of the anatomy of hagfish has not been conducted and as such we sought to produce a comprehensive atlas of the Pacific hagfish (Eptatretus stoutii). Through analysis of gross morphology, as well as light, scanning electron and transmission electron microscopy, each tissue of the hagfish will be documented for use in comparative studies. Intestinal analysis revealed unique cell groupings along the tract; something never before documented. The mucous cells are restricted to the foregut while the hindgut contains unique zymogen granule cells containing acidophilic granules likened to pancreatic enzymes. This distinctive intestine called for physiological studies to uncover other unique aspects such as transporter function and kinetics, specifically of the sodium-glucose linked transporters (SGLT) and glucose transporters (GLUT). The pairing of morphology with physiology could provide understanding of the relationship between the two basal vertebrates that represent the crux of vertebrate evolution.
50) Allison Lewis, George Owttrim, Biol 499, oral presentation
Abstract Title: Redox regulation of RNA helicase expression
The mechanism by which redox sensing is translated into alterations in gene expression remain poorly understood. RNA helicase alteration of RNA secondary structure is associated with the regulation of gene expression. Expression of the RNA helicase CrhR changes in response to temperature either by an upregulation of transcript abundance or by a decrease in proteolytic degradation. An increase in CrhR abundance induced by a downshift in temperature from 30C to 20°C is a redox regulated process, occurring in response to increased reduction of the photosynthetic electron transport chain. Here we investigated if abiotic stresses other than temperature regulate CrhR abundance utilizing various abiotic stresses and artificial methods to manipulate the redox status of the electron transport chain. We observed in all of the treatments that increased electron flow, or the reduction of plastoquinone, resulted in an increase in cellular levels of CrhR; whereas, the oxidation of plastoquinone resulted in decreased abundance of CrhR. These findings suggest that CrhR expression in cyanobacteria is regulated by numerous abiotic stressors through the redox status of plastoquinone, as opposed to temperature exclusively. Results from similar experiments in a mutant cyanobacterial strain are expected to provide further evidence regarding redox regulation of CrhR abundance.