8th ANNUAL

BIOLOGY GRADUATE RESEARCH FORUM

PRESENTED BY THE DEPARTMENT OF BIOLOGY

THURSDAY OCTOBER 19TH – FRIDAY OCTOBER 20TH, 2017

WESTERN UNIVERSITY

Biology Graduate Research Forum 2017 Agenda

Thursday October 19th

4:00–5:00 PM Poster setup PAB Atrium

5:00–5:30 PM Pre-lecture reception PAB Atrium

5:30–5:45 PM

Welcome and opening remarks Dr. Mark Bernards and Jeff Martin PAB 148

5:45–7:00 PM

David Laudenbach Public Lecture

Dr. Mary-Lou Nicholson, RCMP Forensic Scientist PAB 148

7:00–8:00 PM Post-lecture reception PAB Atrium

Friday October 20th

8:30–9:30 AM Poster setup and registration PAB Atrium

9:30–11:00 AM Poster session PAB Atrium

11:00–12:00 PM Panel session PAB Atrium

12:00–1:00 PM Lunch break PAB Atrium

1:00–2:30 PM

Standard talks Concurrent sessions PAB 106 and 150

2:30–2:45 PM Coffee break PAB Atrium

2:45–4:00 PM

Lightning talks Concurrent sessions PAB 106 and 150

4:00–5:00 PM Awards and closing remarks PAB 106

Biology Graduate Research Forum 2017 Schedule of Talks

PAB 150 Standard talks – Concurrent session A

1:00–1:15 PM S1A Alex Kozlov – Sole Fuel Source Selection Strategy to Enhance Pluripotency

1:15–1:30 PM S2A

Carlie Muir – Elevating the embryonic incubation temperature of Atlantic salmon by 4ºC alters cardiogenesis gene expression and cardiac function

1:30–1:45 PM S3A

Freda Qi – Altered microenvironments in tumors and metastatic tissue shape SNP diversity and provide insight on SNP genotypes associated with an aggressive metastatic phenotype

1:45–2:00 PM S4A

Mirindi Eric Dusenge – Boreal Forest respiration in elevated CO2 conditions

2:00–2:15 PM S5A William Burke – RNAi targeting of Manduca sexta using chloroplast-encoded long and short dsRNA fragments

2:15–2:30 PM S6A Yanira Jiménez Padilla – Live yeasts determine development time in Drosophila melanogaster

PAB 106 Standard talks – Concurrent session B

1:00–1:15 PM S1B

Adriano Alonso Pereira Da Cunha – Effect of prolactin and 11-ketotestosterone on parental care behaviour in bluegill sunfish (Lepomis macrochirus)

1:15–1:30 PM S2B

Andrea Boyer – Winter storm cues influence physiological responses of white-throated sparrows

1:30–1:45 PM S3B

Jeff Martin – Winter warming affects the onset of reproduction but not cognition or the hippocampus in Black-capped chickadees (Poecile atricapillus)

1:45–2:00 PM S4B Kimberly Mitchell – Effects of a high-thiaminase diet on reproductive traits in three populations of Atlantic salmon

2:00–2:15 PM S5B Lauren Witterick – Fear of predators has long-lasting effects on the brain and behaviour in wild animals

2:15–2:30 PM S6B Tosha Kelly – Is the cure worse than the disease? Differential behavioural and physiological costs of experimental malaria infection prior to fall migration in song sparrows

PAB Atrium

2:30–2:45 PM Coffee break

PAB 150 Lightning talks – Concurrent session A

2:45–2:53 PM L1A Adam Chin-Fatt – Improving the Stability of a Bovine Secretory IgA Nanobody by Rational Design of the Fragment Crystallisable Chain

2:53–3:01 PM L2A Ariel Frame – Determining the Evolutionarily Conserved Role of Glial Derived Lactate in Drosophila melanogaster Memory

3:01–3:09 PM L3A Craig Matthews – Investigating the role of the miR156-SPL network in heat stress response in Medicago sativa

3:09–3:15 PM Break

3:15–3:23 PM L4A Danielle Spice – Suppressor of Fused regulation of Hedgehog signaling in mouse F9 and P19 cell differentiation

3:23–3:31 PM L5A Nicholas Boehler – Genomic heterozygosity in mice

3:31–3:39 PM L6A

Nicholas Raun – The epigenetic regulator trithorax is necessary for long term memory in Drosophila

3:39–3:45 PM Break

3:45–3:53 PM L7A Rachel Kelly – Pioneering use of mouse genotyping arrays as an instrument for comparative genomics

3:53–4:01 PM L8A Scott Hughes – Plant Volatiles in Insect Pest Control: A promising tool for IPM

PAB 106 Lightning talks – Concurrent session B

2:45–2:53 PM L1B

Chloë Carter – The Effects of Perceived Predation Threat on Stress Response and Memory in Birds

2:53–3:01 PM L2B Christian Therrien – The effect of shelter availability on foraging behaviour in Atlantic salmon (Salmo salar)

3:01–3:09 PM L3B Curtis Lubbe – The Cost of Protection: The Effects of Bud Depth during Dormant and Growing Seasons

3:09–3:15 PM Break

3:15–3:23 PM L4B Joshua Isaacson – Determining if Katanin 60 affects female rejection of males from other species

3:23–3:31 PM L5B Sean McElaney – Nocturnal roosting in shade coffee plantations: Neotropical migrants and the need for safe havens

3:31–3:39 PM L6B Claire Bottini – How does a bad hatching site affect the young bird

health on the short and medium term?

3:39–3:45 PM Break

3:45–3:53 PM L7B Renee Howard – Evaluating wetland restoration success by tracking recovery of plant functional traits

3:53–4:01 PM L8B Tanya Shoot – The role of temperature in zebra finch nest structure and incubation

Oral Presentations – Standard Talks

S1A. Sole Fuel Source Selection Strategy to Enhance Pluripotency Alex Kozlov, PhD Student

Increasing evidence has shown that the cellular metabolic state can regulate the establishment of pluripotency. The metabolic switch from oxidative phosphorylation (OXPHOS) to glycolysis is required during the reprogramming of somatic cells to induced pluripotent stem cells (iPSCs). Pluripotency induction performed under hypoxic conditions, which promotes glycolysis, or by inhibiting OXPHOS during the reprogramming process, increases iPSC production efficiency, highlighting the key role metabolism plays in controlling cellular de-differentiation. In this study, we explored the hypothesis that culturing human foreskin dermal fibroblast (BJDF) cells in various sole metabolite fuel sources will promote a shift in metabolism towards a more glycolytic or bivalent metabolic state. BJDFs were cultured in media containing either glucose, pyruvate or lactate as a sole fuel source. Fibroblasts grown in glucose media exhibited increased phosphorylation of pyruvate dehydrogenase (PDH) compared to cells cultured in control media, indicative of decreased OXPHOS, and a concomitant increase in glycolysis. In contrast, fibroblasts cultured in pyruvate media exhibited a decrease in phosphorylated PDH, indicative of increased OXPHOS. Indeed, cells grown in pyruvate media displayed increased respiration and mitochondrial reactive oxygen species (ROS) compared to control cultures. Finally, fibroblasts cultured in lactate media exhibited a bivalent phenotype, as demonstrated by decreased phosphorylated PDH and increased mitochondrial ROS (markers for increased OXPHOS) as well as increased glycolytic reserve (indicative of increased glycolysis). These findings indicate that sole fuel source selection can alter the metabolic state of differentiated somatic cells, which may make them more amenable to reprogramming for iPSC generation. S2A. Elevating the embryonic incubation temperature of Atlantic salmon by 4ºC alters cardiogenesis gene expression and cardiac function Carlie Muir, PhD Student

Atlantic salmon are cold-water fish which are narrowly adapted to their native temperature

ranges. As water temperature increases beyond their upper thermal limit, fish experience cardiac failure, making salmon very vulnerable to changes in temperature. With predicted temperature increases of 4.8°C in the next century, it is important to understand the effects of elevated temperature on cold-tolerant fish. Previous work suggests that developmental plasticity affects salmonid cardiac development, such that the heart develops to function optimally at temperatures reflecting those experienced during embryonic development. In this study, Atlantic salmon embryos were incubated at 7, 11, and 15ºC. Survivorship was monitored throughout development and embryos were sampled at key stages in cardiac development for real-time PCR analysis of the expression of key cardiogenesis genes (nkx2.5, gata4, mef2c, and tbx5). Embryos reared at 15 ºC experienced significantly higher mortality rates, with declines in survivorship beginning at the time of cardiac looping. Interestingly, this is also when we see the most notable changes in cardiac gene expression. I found that key cardiac development genes were differentially regulated in embryos reared at elevated incubation temperatures, particularly at the time of cardiac looping and heart chamber formation. The spatial expression patterns of these genes is now being examined through in situ hybridizations. Moving forward, I will examine how changes in cardiac gene levels are related to heart morphology (via histology), cardiac function (via novel Doppler technology), and thermal physiology (via critical swim speed measurements), to understand how salmon species may be affected by rising temperatures.

S3A. Altered microenvironments in tumors and metastatic tissue shape SNP diversity and provide insight on SNP genotypes associated with an aggressive metastatic phenotype Freda Qi, MSc Student

The dynamic interactions in genetic and microenvironment changes with tumorigenesis and metastasis are poorly understood. Here, we use single nucleotide polymorphic (SNP) loci as sentinels to investigate mutagenesis and selection arising in the MMTV-PyMT transgenic mouse model of primary mammary tumorigenesis and lung metastasis. Microenvironment differences are achieved by knockout of Receptor for Hyaluronan-mediated Motility (RHAMM). Phenotypically, RHAMM loss is associated with unchanged tumorigenesis but more aggressive metastasis. We used the Mouse Diversity Genotyping Array to examine de novo mutations at 220,615 SNP loci in the primary tumor and metastatic tissue of three Rhamm+/+ and three Rhamm-/- mice. Based on the number of unique mutations in each tissue, Rhamm+/+ mice showed higher inter-animal variation, whereas Rhamm-/- mice showed greater inter-animal homogeneity. The RHAMM loss microenvironment produced a 13.8-fold increase in the number of unique mutations in the metastatic tissue compared to the primary tumor, consistent with the more aggressive metastatic phenotype observed in Rhamm-/- mice. Ratios of mutations in protein-coding, regulatory, and intergenic regions genome-wide were compared to synonymous substitutions to infer selective pressures in each microenvironment. Gene regions were generally found to be under positive selection in primary tumors, regardless of RHAMM status. However, SNP loci in metastatic tissue of Rhamm-/- mice were found to be under strong purifying selection. We identified 342 mutations in 124 candidate genes that may be underlying aggressive metastasis in Rhamm-/- mice. We predict altered microenvironments arising with RHAMM loss elevates de novo mutations refined through purifying selection for an “advantageous” aggressive metastatic phenotype.

S4A. Boreal Forest respiration in elevated CO2 conditions Mirindi Eric Dusenge, PhD Student

Boreal forests are often assumed to be temperature-limited, and warming is therefore expected to stimulate their carbon uptake. However, much of our information on the ability of boreal conifers to acclimate photosynthesis and respiration to rising temperatures comes from seedlings. We

measured net CO2 assimilation rates (A) and dark respiration (R) at 25 C (A25 and R25) and at prevailing growth temperatures (Ag and Rg) in mature Picea mariana (spruce) and Larix laricina

(tamarack) exposed to ambient, +2.25, +4.5, +6.75 and +9 C warming treatments in open top chambers in the field at the SPRUCE experiment (MN, USA).

In spruce, A25 and Ag were similar across plots in May and June. In August, spruce in warmer treatments had higher A25, an effect that was offset by warmer leaf temperatures in the Ag data.

In tamarack, A25 was stimulated by warming in both June and August, an effect that was mainly offset by higher leaf temperatures when Ag was assessed in June, while in August, Ag was still slightly higher in the warmest treatments (+6.75 and +9) compared to the ambient plots. In spruce, R25 was enhanced in warm-grown trees in May, but was similar across treatments in June and August, indicating little acclimation of R. Rg slightly increased with warming treatments across the season in spruce. In contrast, R in tamarack thermally acclimated, as R25 decreased with warming. But while this acclimation generated homeostatic Rg in June, Rg in August was still highest in the warmest treatments.

Our work suggests that the capacity for thermal acclimation in both photosynthesis and respiration varies among boreal tree species, which may lead to shifts in the performance of these species as the climate warms.

S5A. RNAi targeting of Manduca sexta using chloroplast-encoded long and short dsRNA fragments William Burke, MSc Student

Modifying plant genomes with transgenes expressing insecticidal dsRNA is a promising method of providing crops with species-specific pest resistance. However, RNAi is more readily induced in insects when intact dsRNA is consumed, and previous attempts at expressing dsRNA within the nucleus of plant cells have proven to be inefficient due to cleavage of the dsRNA into siRNA prior to insect consumption. To avoid processing within the cells of the plant, dsRNA can be expressed within the chloroplast, which evolved from free-living cyanobacteria and do not express the proteins involved in the RNAi pathway. For my research project, I use biolistic particle delivery to transform the chloroplast genome of tobacco, Nicotiana tabacum, with genes expressing either 2222 or 259 bp long dsRNA that are complementary to mRNA encoding v-ATPase subunit A within the midgut cells of the tobacco hornworm, Manduca sexta, in order to a crop resistant to this species of insect. As the first study to investigate the use of long and short chloroplast-encoded insecticidal dsRNA targeting the same gene, my research will determine whether there is any difference in effectivity that can be attributed to the length of the dsRNA used and whether there is any difference in the quantity of dsRNA that is expressed and stored with varying product size. The results of this study will have use in the future of the pest control industry as well as in other fields, such as dsRNA cancer therapy delivery for medical use. S6A. Live yeasts determine development time in Drosophila melanogaster Yanira Jiménez Padilla, PhD Student

The gut of insects is host to bacteria, archaea, fungi, protozoans and viruses, and together they affect host physiology. Most studies have focused on the bacterial microbiota, but little is known about the other members of the gut flora. The gut microbiota of Drosophila melanogaster is relatively simple, and its bacteria and yeast species have been characterized, thus making it a useful system for understanding the role of yeasts in insect physiology. Yeasts are usually regarded as a food source; however, here we show that the effect of yeasts on D. melanogaster development is not solely explained by the nutritional content of the yeast. To investigate the effect of yeast on Drosophila development time, we started by rearing the flies either as axenic (free of microbes), or gnotobiotic (with a known yeast species in their gut), and recorded the pupation and eclosion times. We used two species of yeast, Saccharomyces cerevisiae, which is commonly used in lab settings and Lachancea kluyveri, which can be recovered from the gut of some wild caught Drosophila species. Both yeasts reduce development time equally, and the biggest effect is observed when the yeast is alive (gnotobiotic flies). While heat-killed yeast and nutritional supplements reduce the development time in axenic flies, they do not replicate the effect of live yeasts.

S1B. Effect of prolactin and 11-ketotestosterone on parental care behaviour in bluegill sunfish (Lepomis macrochirus) Adriano Alonso Pereira Da Cunha, PhD Student

Animals that provide parental care to their offspring face a potential trade-off between two kinds of behaviours: (1) aggressive behaviours that defend offspring from predators, and (2) nurturing behaviours that provide offspring with food or shelter. Hormones have been proposed as important mediators of the trade-off between these behaviours, and specifically, androgens might promote aggressive behaviours while prolactin promotes nurturing behaviours. I tested the effects of these hormones on parental care behaviours in bluegill sunfish, a species in which males build nests and provide sole parental care to the offspring. Parental males received one of five hormone manipulation treatments: (1) placebo; (2) 11-ketotestosterone (11-KT); (3) flutamide, an 11-KT antagonist; (4) prolactin; and (5) bromocriptine, a prolactin-release inhibitor. I then observed the frequency of nurturing and aggressive parental care behaviours. I found that prolactin was associated with significantly more frequent nurturing behaviours relative to the other treatments. Increased 11-KT was associated with more frequent aggressive behaviours relative to the other treatments. These findings indicate that both prolactin and 11-KT influence parental care in a fish. S2B. Winter storm cues influence physiological responses of white-throated sparrows Andrea Boyer, PhD Student

Climate change has been linked to an increasing frequency of inclement weather and winter storms. As such, it is important to understand the effects changing weather patterns have on birds. We investigated the effects of experimental recurrent inclement winter weather cues on body composition, glucocorticoid hormones, and behavior of white-throated sparrows. We used a hypobaric climatic wind tunnel to simulate storms by altering barometric pressure and temperature accordingly, and measured behavioral responses, body composition, and baseline CORT levels in birds exposed, or not exposed, to weekly simulated storms over a three month period. Experimental birds developed significantly higher fat and lean masses. Baseline CORT levels decreased over time in both groups, and time spent at food cups increased over time in both groups. Thus, although manipulations did not have a detectable effect on baseline CORT, it did affect body composition. This research provides novel experimental evidence that birds detect changing weather patterns and respond appropriately, and indicates that repeated exposure to inclement weather cues directly affects birds’ energy reserves.

S3B. Winter warming affects the onset of reproduction but not cognition or the hippocampus in Black-capped chickadees (Poecile atricapillus) Jeff Martin, PhD Student

The effects of overwinter temperature on behaviour and cognition, hippocampal volume, and reproductive timing were studied in Black-capped chickadees (Poecile atricapillus). I hypothesized that overwinter temperature would have varied effects for Black-capped chickadees that overwinter in northern climates. I found that temperature had no effect on behaviour and cognition, or hippocampal volume, but temperature did influence reproductive timing. Birds that experienced warmer winter conditions had significantly more developed gonads than birds that experienced colder conditions. These results suggest that while birds are clearly sensitive to ambient winter temperature, temperature only modulates some processes and not all. These studies provide the basis for continued exploration into the effects of environmental change on avian populations, and can help influence current and future conservation and policy decisions.

S4B. Effects of a high-thiaminase diet on reproductive traits in three populations of Atlantic salmon Kimberly Mitchell, MSc Student

Atlantic salmon were once abundant in Lake Ontario, but were extirpated more than a century ago. There have been multiple attempts to reintroduce Atlantic salmon into Lake Ontario, but these attempts have not yet produced a self-sustaining population. One potential obstacle is the introduction of invasive prey fishes into Lake Ontario, including alewife and rainbow smelt. These fishes contain high concentrations of the enzyme thiaminase, which breaks down the essential vitamin thiamine (B1) and can induce thiamine deficiency in salmon that consume this enzyme. We compared the effect of dietary thiaminase on reproductive traits in three Atlantic salmon populations (LaHave, Lac Saint-Jean, Sebago), which have previously been used in reintroduction efforts. We hypothesized that a high-thiaminase diet would affect reproductive traits and these effects would differ among the three populations. To test our hypotheses, we performed experimental crosses with our low- and high-thiaminase treatment individuals within populations and measured reproductive traits. We present data on the effects of dietary thiaminase levels on mortality, yolk conversion efficiency, specific growth rate, thiamine concentrations and sperm quality. We further use this data to assess the susceptibility of the three Atlantic salmon populations to a high-thiaminase diet, as is present in Lake Ontario, and inform best practices for managing the Atlantic salmon reintroduction effort in Lake Ontario.

S5B. Fear of predators has long-lasting effects on the brain and behaviour in wild animals Lauren Witterick, PhD Student

Predators affect prey populations not only through direct killing, but also through perceived predation risk – the ‘fear’ of predators. Responding to predation risk is critical for prey survival, however perceived predation risk can have lasting effects ranging from individual changes in neurobiology up to population level effects. To experimentally test the lasting effects of predator ‘fear’ on the brain and behaviour, we manipulated perceived predation risk using auditory playbacks of predators or non-predators in wild caught black-capped chickadees (Poecile atricapillus) in acoustic isolation and wild caught brown-headed cowbirds (Molothrus ater) in large outdoor aviaries. We found differences neurogenesis and dendritic morphology one week after exposure to increased predation risk, and differences in escape behaviour and responses to predator alarm calls both during the predation risk manipulation and one week post treatment. Our research aims to integrate results from biomedical research showing long-lasting fear effects on the brain in lab animals (rats) with fear-induced behavioural changes documented by ecologists in the field. S6B. Is the cure worse than the disease? Differential behavioural and physiological costs of experimental malaria infection prior to fall migration in song sparrows Tosha Kelly, PhD Student

Migratory birds move through multiple habitats and thus encounter a diverse suite of parasites. This raises concern over migrants’ potential role in transporting infectious disease between the breeding and wintering grounds, and along migratory flyways. Trade-offs between migration and immunity may result in parasitized individuals delaying migration, with important effects on infection dynamics. However, experimental evidence that parasitic infection affects migratory timing remains scant. We hypothesized that birds encountering haematozoan parasites shortly before migration incur behavioural (i.e., delayed migration) and physiological costs (reduced body condition), due to the infection itself and/or to the costs of mounting an immune response. To test this hypothesis, we experimentally inoculated song sparrows (Melospiza melodia) with an endemic strain of Plasmodium shortly before fall migration. We monitored infection success and body composition, and used radiotelemetry to track migratory departure. Relative to controls inoculated with unparasitized blood, and birds that successfully resisted infection, birds that became infected left the study area somewhat later. This difference was not statistically significant, however, suggesting that infection delays migration only modestly. By contrast, birds that resisted infection had lower lean mass twelve days post-exposure than either controls or birds that became infected. This suggests trade-offs between body composition and immunity, either because resistance is energetically costly and/or because individuals with greater initial lean mass are more susceptible to infection. Experimentally evaluating the effects of infection and resistance on migratory timing and preparation in free-living animals is increasingly crucial as parasite and vector ranges shift in response to a changing climate.

Oral Presentations – Lightning Talks L1A. Improving the Stability of a Bovine Secretory IgA Nanobody by Rational Design of the Fragment Crystallisable Chain Adam Chin-Fatt, PhD Student

The secretory IgA nanobody is a modular molecule comprising two highly ordered constant domains, collectively the fragment crystallisable (Fc), that are significantly more conserved than their fused antigen binding partner, the variable heavy chain fragment (VHH), which comprises a spectrum of sequences depending on their corresponding binding partners. Considering that the Fc may confer stability to its various VHH partners, rational design of the Fc was enabled by bioinformatic analysis and molecular modeling to predict key amino acid substitutions that may induce either supercharging of the molecule or disulfide bond formation. These predicted stabilizing mutations were then enabled by site directed mutagenesis of the native bovine Fc sequence and screened for protein accumulation and thermostability following transient expression into leaves of Nicotiana benthamiana. Our results so far have identified six candidates that show better accumulation and enhanced thermostability. Furthermore, the mutants can be pyramided for cumulative increases of accumulation. To determine if these Fc mutants can confer their enhanced stability to the whole secretory IgA molecule, they are currently being fused to a variable heavy chain (VHH) that binds Enterohemorrhagic Escherichia coli and will be co-expressed with the joining chain, that binds together VHH-Fc dimer pairs, and the secretory component, that wraps around the joined tetramer. Binding efficacy of the structural mutants to enterohemorrhagic E. coli will also be tested. The goal of this project is to develop a stabilized bovine Fc chain that could potentially be a generic stabilizing scaffold for various VHH’s and the corresponding secretory IgA. L2A. Determining the Evolutionarily Conserved Role of Glial Derived Lactate in Drosophila melanogaster Memory Ariel Frame, MSc Student

Glial cells support active neurons by providing them with lactate. Studies using mice, rats and chickens have provided evidence that the shuttling of lactate from glia to neurons is important for memory. However, it is unknown if glial-derived lactate affects memory in an evolutionary conserved manner. This question will be answered by assessing the role of glial-derived lactate in memory using Drosophila melanogaster (flies), an invertebrate that has been used extensively to model human diseases. Flies possess glia which function similarly to vertebrate glia. Recently, it was reported that fly brain glial support neuron survival by providing them with alanine or lactate. Here we tested the hypothesis that lactate generated by glial cells, and metabolized in neurons, promotes memory formation in flies. Courtship-Conditioning (CC) is a behavioural memory assay which tests the ability of male flies to remember prior exposure to unreceptive females. CC was used to test memory of flies which had been genetically altered to either increase or decrease expression of lactate dehydrogenase, the rate limiting enzyme of lactate production. Preliminary results suggest that flies with reduced glial lactate production have impaired memory performance; while flies with increased glial lactate production have enhanced memory performance. These results will further understanding of the fundamental role which glia play in memory formation as well as provide a novel model to understand the role that glial-derived lactate plays during age-dependent and disease-associated cognitive decline.

L3A. Investigating the role of the miR156-SPL network in heat stress response in Medicago sativa Craig Matthews, MSc Student

Extreme temperatures adversely affect plant development and, as a result, crop production. Heat stress affects cellular function and results in increased potential evapotranspiration. Heat stress induced changes to plant water status can be especially harmful when combined with drought. Alfalfa (Medicago sativa) is an important forage and potential bioenergy crop in Canada and world-wide. The development of heat stress-tolerant cultivars would be beneficial to reduce production loss as mean annual temperatures in Canada rise. Members of the highly conserved miR156 family regulate the Squamosa Promoter-Binding Protein-like (SPL) genes that are involved in plant growth and development and are differentially expressed in response to various stresses, including heat stress. In this study, we investigate the role of miR156 in heat stress tolerance using alfalfa overexpressing the miR156d precursor at 40°C. Overexpression plants showed reduced leaf relative water content and increased midday leaf water potential under heat stress after four days and increased leaf chlorophyll and β-carotene contents after 6 days. Preliminary survival analysis data suggest miR156d overexpression may also increase heat stress tolerance. Expression analysis of miR156 and its target SPL genes in alfalfa subjected to heat stress over time suggest miR156 expression is induced by heat stress and identified downregulated SPL gene targets for further investigation using overexpression and RNAi knockdown plants. L4A. Suppressor of Fused regulation of Hedgehog signaling in mouse F9 and P19 cell differentiation Danielle Spice, MSc Student

F9 and P19 cell lines require the activation of Hedgehog signaling to differentiate into extraembryonic endoderm and neurons, respectively, and this can be induced by retinoic acid. Suppressor of Fused plays a key role in the negative regulation of Hedgehog signaling and therefore during differentiation its function(s) must be attenuated for the pathway to be in the on state. It is hypothesized that Suppressor of Fused (SUFU) acts as a master regulator of F9 and P19 differentiation and that this protein uses a combination of cellular localization, abundance and protein-protein interactions to regulate Hedgehog signaling in these cell lines. To address this qRT-PCR was used and Western blotting where SUFU levels have no change in protein abundance in F9 cell differentiation to extraembryonic endoderm, but decease with P19 differentiation to neurons. SUFU localization changes with differentiation of P19 cells moving from a uniform localization to almost entirely nuclear. By examining the changes in SUFU localization, abundance and interactions with various binding partners we will have a better understanding of how Hedgehog signaling is involved in F9 and P19 cell differentiation.

L5A. Genomic heterozygosity in mice Nicholas Boehler, MSc Student

Elevated mutation rates have been shown to localize with heterozygosity in Arabidopsis, possibly due to chromosomal mispairing during meiosis. Using novel spatial statistical tools, we investigated this mutational phenomenon in mice. The Mouse Diversity Genotyping Array was used to detect genotypes at 493,290 single nucleotide polymorphic (SNP) loci and identify significant spatial association between heterozygosity and copy number variants (CNVs). We investigated genomic heterozygosity and occurrence of CNVs for 30 inbred parental mice (0 to 5% heterozygosity), 279 Naval Medical Research Institute (NMRI) outbred mice (5 to 7% heterozygosity), 99 CD-1 outbred mice (10 to 11% heterozygosity), and 67 first filial generation (F1) mice (19 to 53% heterozygosity). There was no correlation between % heterozygosity and the number of CNVs for parental mice that had ≤ 0.15% heterozygosity (laboratory strains). In contrast, a moderate positive association (r2 = 0.40) was observed for parental mice with 1.41% to 4.95% heterozygosity (wild-derived strains). More proximal spatial associations between CNVs and heterozygous SNPs were observed for the chromosomes of wild-derived parental mice compared to laboratory parental mice. CNVs and localized heterozygosity appear linked to the germline and thus meiosis rather than mitosis. These observations are consistent with a possible two-step mechanism to CNV formation: Heterozygosity leading to chromosome mispairing with homologous regions facilitating non-allelic homologous recombination. Current research is directed at verification of this mechanism through examination of F2 (F1 x F1) mice. L6A. The epigenetic regulator trithorax is necessary for long term memory in Drosophila Nicholas Raun. MSc Student

Epigenetic regulation is important for the initiation and maintenance of the gene expression changes required for long term memory. One specific epigenetic mark required for memory is the trimethylation of Histone H3 Lysine 4. In Drosophila melanogaster the gene trithorax (trx) is capable of producing this mark, but its role in memory has yet to be identified. Here I used RNAi to knockdown trx specific to the fly memory control region, the mushroom body (MB). I found that MB-specific trx knockdown flies have long term memory deficits, but display normal short term memory. Currently, using a temporally controlled RNAi knockdown system, I am conducting experiments to discern whether trx knockdown effects memory through developmental mechanisms, or through acute effects on gene regulation in the adult brain. Subsequently, I will use MB-specific RNA-sequencing to identify genes and pathways that are misregulated in trx knockdown MBs. This study has identified trx as a specific regulator of long term memory in Drosophila, and will help to further understand specific epigenetic mechanisms that are important in learning and memory.

L7A. Pioneering use of mouse genotyping arrays as an instrument for comparative genomics Rachel Kelly, MSc Student

Researchers working with non-model organisms are pioneers, facing the challenges of characterizing genetic diversity but lacking low-cost technologies available compared to researchers with the abundance of knowledge and tools available for model organisms. Single nucleotide polymorphism (SNP) genotyping microarrays use genome-wide targets to characterize genetic variation within and between model organisms efficiently and cost effectively. Recently, researchers applied microarrays cross-species to determine if there are shared SNPs between model and non-model organisms. The Mouse Diversity Genotyping Array (MDGA) is a versatile and high-density genotyping technology that has been used extensively to map SNP diversity of Mus musculus (the house mouse). The MDGA has been applied to squirrel, tapir, and rhino DNA samples. We analyzed these samples and investigated cross-species application of the MDGA for 27 diverse species in the genus Mus and DNA of other mammalian species. Forty publically available MDGA output (CEL) files for DNA from Mus and other mammalian species were analyzed to assess application of the MDGA cross-species. Inclusion of non-Mus samples resulted in underestimates of genetic distance. Within Mus, data show that SNP genetic distances replicate known divergence times. The MDGA appears to be a useful tool for examining SNP diversity within Mus, but sadly not beyond this genus. The top pathway enriched for hypervariable genes is adherens junction and the top pathway enriched with genes containing invariant SNP genotypes is the retrograde endocannabinoid signaling pathway. These findings are consistent with previous literature supporting the use of the MDGA cross species within the genus Mus. L8A. Plant Volatiles in Insect Pest Control: A promising tool for IPM

Scott Hughes, MSc Student

Integrated pest management (IPM) aims to use multiple control mechanisms in order to reduce insect pest populations in a sustainable fashion. The utilization of transgenic plants as a potential new tool for IPM is a growing area of interest. Plant volatile organic compounds (VOCs) play an important role in plant-insect interactions, and these interactions can be influenced and exploited by manipulating the expression of the genes involved. Previously, our group showed that overexpressing carotenoid cleavage dioxygenase (CCD) family members increases the production of repellent apocarotenoid volatiles in Arabidopsis thaliana. As a continuation of this work, we have successfully produced tomato Solanum lycopersicum plants overexpressing AtCCD4. Expression analysis of AtCCD4-OE lines showed a wide range of overexpression levels. Static headspace sampling of leaf VOC emissions using solid phase micro-extraction (SPME) and subsequent gas chromatography-mass spectrometry (GC-MS) analysis revealed differences in VOC profiles between empty vector (EV) control and AtCCD4-OE plants. In initial dual-choice oviposition bioassays using greenhouse whitefly Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) as a generalist pest model, AtCCD4-OE plants showed a trend, albeit statistically insignificant, towards having a repellent effect. Future work will focus on VOC analysis of tomato flowers and fruits, additional dual-choice and no-choice oviposition bioassays, and Y-tube olfactometer assays. Long term, plants with altered VOC profiles could act as trap crops or pest repellent crops within a “push-pull” IPM strategy, and could additionally aid in the maintenance of beneficial insect populations within a crop.

L1B. The Effects of Perceived Predation Threat on Stress Response and Memory in Birds Chlöe Carter, MSc Student

The perception of a predator is enough to elicit a strong stress response which effects behaviour and hormones within an organism. Perception of a predator can come through numerous sensory pathways. Being able to utilize multiple sensory pathways is adaptive as the more quickly a predator can be detected the faster the response can occur, and the higher the likelihood of survival.

This study is investigating the hormonal and behavioural changes in response to perceived predator risk in birds. Specifically, my first project focuses on the corticosterone and behavioural response to perceived predator risk when presented across three different sensory systems (audition, vision, and olfaction) in different species of wild-caught and lab-bred birds. This will be examined through hormone assays to determine the level of corticosterone present in the blood, as well as video analysis of behaviours before and during the exposure treatments. The second project focuses on memory retention after chronic presentations of auditory perceived predator risk in wild-caught birds. Data collection and analysis is currently underway.

This study will be the first to examine perceived predator threat across different sensory systems in wild-caught and lab-bred birds using the same protocol and analyses. These comparisons will provide insight into how birds respond to different sensory stimuli. More broadly, information attained from this study will build on and support the evidence that perceived predation threat can influence behaviour and memory.

L2B. The effect of shelter availability on foraging behaviour in Atlantic salmon (Salmo salar) Christian Therrien, MSc Student

Juvenile Atlantic salmon (Salmo salar) use several anti-predator behaviours to reduce their vulnerability to predation, such as utilizing shelters and changing the timing of foraging behaviour to avoid predators. However, these anti-predator behaviours come at the cost of lost foraging opportunities, which in turn can reduce growth and lead to reduced fitness later in life. Despite shelter use being an important anti-predator behaviour, how shelter availability influences the foraging behaviour of fish in the wild is not well-documented. To address this knowledge gap, I will measure the feeding and activity of juvenile Atlantic salmon from two populations while they are held in net pens that differ in their level of shelter. I predict that in an environment with low shelter availability, juvenile salmon will prioritize foraging over sheltering in order to maintain a high growth trajectory to reduce the length of time they are susceptible to gape-limited predators.

L3B. The Cost of Protection: The Effects of Bud Depth during Dormant and Growing Seasons Curtis Lubbe, PhD Student

Frost is a major stress that greatly impacts the distribution of plant species. Non-woody plant species can survive areas with regular frost only if they can avoid or tolerate freezing stress. Many plants avoid freezing stress by placing buds at or below ground level where they are insulated by snow, litter, or soil. Belowground overwintering structures also can be clonal and function as a method of asexual reproduction. Although it can protect, increased bud depth may have a cost when frost stress is absent. Shallow bud placement may facilitate early season growth and provide a competitive advantage over neighbouring plants. Six bulbous, herbaceous, plant species were subjected to a suite of experiments to decouple the effects of bud depth on frost tolerance and competitive ability in the spring. In the field, plants were buried in the fall at one of three depths, and half of the plants experienced snow removal to allow greater frost penetration into the soil. In a second experiment, plants were exposed to one of six freezing temperatures under controlled conditions. Emergence (when possible), height, and biomass were measured and data were analyzed through ANOVAs. Preliminary results of the field experiment indicate a trend of greater growth with depth, probably a result of frost stress avoidance. Controlled freezing temperature exposure has yielded a trend toward increased mortality and decreased growth with greater freezing severity. L4B. Determining if Katanin 60 affects female rejection of males from other species Joshua Isaacson, MSc Student

During courtship, it is extremely important for organisms to be able to recognize whether their potential mates are from their own species because of the heavy costs associated with forming interspecies hybrids. Hybrid offspring are often inviable or infertile because of incompatible genes inherited from both parental species. Many organisms use species-specific cues to recognize potential mates. These cues are then perceived and evaluated via neural pathways. The underlying genetic basis of how species-specific cues are evaluated and subsequently processed into either receptive or rejectionary behaviour remains almost entirely unknown. This project aims to determine whether the gene Katanin 60, which is involved in neuron development in Drosophila species, is involved in species identification during courtship. I will use the CRISPR/Cas9 system to knock out either the Drosophila melanogaster or D. simulans allele of Katanin 60 in interspecies hybrids and see if this results in melanogaster-like or simulans-like female mating behaviour. Complementary to this, I will silence each species' Katanin 60 allele using allele-specific RNAi that is expressed in particular subsets of neurons via the Gal4/UAS system in hybrids. Differences in behaviour would indicate that Katanin 60 is involved in species recognition during courtship via the particular subset of neurons. If successful, this would be the first time that a gene has been linked to interspecies mate rejection, and provides the first insight into which neurons contribute to that behaviour.

L5B. Nocturnal roosting in shade coffee plantations: Neotropical migrants and the need for safe havens Sean McElaney, MSc Student

Shade coffee plantations provide wintering Neotropical migrants with an alternative to primary forest which has disappeared throughout most of their range. However, it remains unclear whether plantations can provide enough structure to maintain viable wintering populations of many species. We studied Swainson’s Thrush (Catharus ustulatus) wintering in two different sites in the Colombian Andes that consisted of a mixture of montane forest and shade grown coffee plantation. Using handheld telemetry, we examined how birds’ (n=40) use of habitat varied between their daytime territories and their nighttime roosts. Although some birds spent the day in shade coffee, most used denser (natural) forest for roosting at night. We quantified the structural characteristics of roosting habitat (canopy height, canopy cover, and understory density). Remnant patches of forest provided birds with presumably safer roosting sites compared to shade coffee per se. The efficacy of shade grown coffee plantations as wintering habitat can be improved if matched with remnant forest patches. L6B. How does a bad hatching site affect the young bird health on the short and medium term? Claire Bottini, PhD Student

In their natural habitat, wildlife has to face multiple stressors (i.e. predation, food unpredictability, climate change) in addition to pollutants burden. While growing evidences suggest that stress worsen the impact of contamination, toxicant exposure might alter the ability to cope with stressful situations. Such impairment brings high risks for animals, especially during energetic life stages such as growth and migration.

Effectively, since sub-lethal doses of mercury increase organisms oxidative stress, altering their neural, immune and endocrine systems, while instead, chronic stress first influences individuals’ endocrine systems, with consequences on their immunity and oxidative homeostasis, all those interactions would subsequently disrupt animals’ behaviour and physical ability, impairing their ability to migrate and ultimately their fitness.

This study aims to determine the relationship between stress and mercury exposure and the effects on young birds. Therefore Song Sparrow (Melospiza melodia) juveniles will be captured and dispatched in four environmentally relevant treatments: control, stressed only, mercury exposed only, and both stress with mercury exposition. An immune, hormonal, neurologic, behavioural and metabolic approach will be applied to monitor their health. I expect that mercury and stress will have different relationship according to the biomarker used, with for example synergic effects on oxidative stress, additive on immunity markers and compensatory influences on stress endocrine system. Additionally, I suspect that migration behaviour will be disrupted in both mercury exposed groups.

In conclusion, mercury pollution is still a very actual concern for wildlife populations to whom the impacts in real life situation still requires more investigations.

L7B. Evaluating wetland restoration success by tracking recovery of plant functional traits Renee Howard, MSc Student

Wetlands are important ecosystems but many have been lost due to intensification of human

activities on the landscape. Wetland restoration efforts have increased in response to greater recognition of important functions that wetlands play in flood mitigation, water purification, biodiversity, and carbon sequestration. The recovery of wetland functions is often assessed by comparing the community composition of restored wetlands to that of a natural wetland. However, community composition might not be the best determinant of restoration success as it does not reflect wetland function. Instead, using functional traits may provide improved insights into the potential recovery of functions and associated services. My research aims to analyze plant functional traits of restored wetlands to understand how ecosystem functions change with time since restoration. Data acquired from field collections (quadrat sampling, plant samples, and soil samples) of nearly 40 seasonal wetlands and plant functional trait database queries will be combined to evaluate functional traits and functional diversity. It is anticipated that this research will provide a better understanding of the potential for wetland functional recovery following restoration, will determine whether plant functional traits are effective indicators of wetland function, and may help inform policy and wetland management efforts across the country.

L8B. The role of temperature in zebra finch nest structure and incubation Tanya Shoot, MSc Student

Nest-building is a behaviour that is seen throughout the animal world, perhaps most often seen

in bird species. Nest-building in birds has long been considered an innate behaviour that individuals are capable of from birth, rather than a behaviour that is dependent on experience. Recent literature, however, suggests that there are experience-based, cognitive mechanisms that allow birds to adapt their nests and behaviours in response to environmental cues. My research examines these cognitive mechanisms, specifically how birds modify their nest-building and incubation behaviour in response to ambient temperature, and the effect on the resulting hatchlings. Thirty-six pairs of zebra finches (Taeniopygia guttata) were assigned to one of two conditions (30°C and 14°C), and provided with ad libitum access to nest-building material. Pairs built nests, laid and incubated eggs, and raised nestlings. To assess the physiological costs associated with nest-building and reproduction, body composition measurements were taken. Results suggest that zebra finches can adapt their nests in response to ambient temperature, with the birds experiencing colder conditions incorporating more string into their nests than birds experiencing warmer conditions. Incubation signatures appear that the two conditions are employing different strategies to maintain the same desired incubation temperature. The hatchlings from the 14°C condition hatched earlier and were more numerous than the 30°C condition, however less survived. These results further suggest that birds can alter reproductive behaviours in response to environmental cues, and add to the growing body of literature which suggests that nest-building and incubation is an experience-moderated behaviour.

Posters

P1. Mechanisms which regulate dorsal-ventral patterning of the pharynx in Xenopus laevis Alex Szpak, MSc Student

The pharynx is crucial to the survival of all vertebrates since the pharynx facilitates respiration by connecting the nasal and oral cavity to the larynx and connecting the oral cavity to the esophagus allowing for digestive functions. Even though the pharynx displays dorsal-ventral patterning and much is known about the morphogenesis and anterior-posterior patterning of the pharynx, currently there is little information identifying the underlying mechanisms that drive dorsal-ventral patterning. This is in part due to the complexity of the pharynx that requires contributions from all three germ layers: the endoderm, mesoderm and ectoderm, along with neural crest cells. The expression profiles of Sonic Hedgehog (Shh) and Bone morphogenetic Protein 4 (Bmp4) adjacent to the developing pharynx are reminiscent of their expression around the neural tube were they regulate dorsal-ventral patterning. Therefore, I hypothesized that Shh and Bmp4 are the signaling molecules that regulate dorsal-ventral patterning of the developing pharynx. To test this, Xenopus laevis embryos were treated with small molecular reagents that have been shown to be effective activators or inhibitors of either the Shh or Bmp signaling pathway. The effects on the dorsal-ventral patterning of the developing pharynx were assessed by whole mount in situ hybridization for mRNAs that are expressed in the ventral, intermediate or dorsal regions of the developing pharynx. The inhibition of Bmp4 lead to the predicted ventral shift of the dorsal-ventral pattern. This indicates Bmp4 may be a contributing factor in the regulation of the dorsal-ventral patterning of the developing pharynx.

P2. Nitrogen limitation and source alter the effects of low CO2 on plant performance Andre Galvao Duarte, PhD Student

Low atmospheric CO2 concentrations dominated the recent evolutionary history of plants. However, our knowledge of plant performance in low CO2 environments is poor, and that of how low CO2 interacts with nitrogen source and availability is even poorer. Here, we investigated growth, photosynthetic traits and nitrogen isotopic signature in Elymus canadensis, grown from seed at either current CO2 concentrations (400 ppm) or values representative of the last glacial maximum (180-190 ppm), in combination with either high or low nitrogen supply, with the high nitrogen treatment supplied as nitrate, ammonium, or a mix of both. Low CO2 reduced total biomass by almost half, except when nitrogen was limited, where growth was unaffected by CO2. Plants grown with nitrate, ammonium, or at low nitrogen up-regulated photosynthesis at low CO2, presenting higher maximum electron transport rates (Jmax), but not maximum Rubisco carboxylation rates (Vcmax), than plants grown at ambient CO2. Growth at low CO2 also increased leaf nitrogen concentrations. Compared to plants from ambient CO2, low CO2 plants were enriched in 15N (1.2‰) under nitrate fertilization, but 0.8‰ depleted under low nitrogen availability. Our work demonstrates that the effects of low CO2 on plants varies depending on nitrogen source and availability; such responses should be considered when inferring data about plant responses to past climates, especially when carbon resources were most limiting.

P3. Can we detect arogenate dehydratase activity in vivo? Emily Clayton, PhD Student

Phenylalanine (Phe) is an essential amino acid that can be synthesized through two pathways: the arogenate and the prephenate pathway. The prephenate pathway involves converting prephenate to phenylpyruvate in a decarboxylation/dehydration reaction by a prephenate dehydratase (PDT), followed by a transamination of phenylpyruvate to Phe by a phenylpyruvate aminotransferase (PPAT). The arogenate pathway requires the transamination of prephenate to arogenate by a prephenate aminotransferase (PAT), then a decarboxylation/dehydration of arogenate to Phe by an arogenate dehydratase (ADT). ADTs and PDTs catalyze the same type of reaction and are very similar in sequence. PDT activity can be easily determined in vivo using a yeast complementation test in the PDT knockout Saccharomyces cerevisiae pha2 strain. There currently is no in vivo test for ADT activity, and biochemical assays are problematic as the substrate of an ADT, arogenate, cannot be purchased. We have developed a method to detect ADT activity in vivo. ARO8 and ARO9 encode the two S. cerevisiae PPATs required for Phe synthesis via the prephenate pathway. Mating single knockout strains and sporulating the diploid generated a haploid double knockout strain. As predicted, the Δaro8aro9 knockout is Phe requiring. This yeast strain will be transformed with an AtPAT to introduce the arogenate pathway. In the presence of a PAT, an ADT will complete the pathway to synthesize Phe in this yeast strain. This unique assay will be the only in vivo test of ADT activity able to distinguish between ADT and ADT/PDT activity. P4. Identifying the neural circuitry necessary for proper social spacing through the lens of Drosophila neuroligin 3 J. Wesley Robinson, MSc Student

Fruit flies exhibit simple social behaviours when brought in close proximity by certain

environmental factors such as presence of food. A preferred spacing distance can be quantified in Drosophila using social space assays. Determination of spacing could be attributed to many factors such as signal transduction throughout the nervous system. So far, it has been determined that the mushroom bodies (MB), a relay integration center in fly brains, are important for social space. In addition, the dopaminergic signalling pathway has been identified as modulators of spacing. Finally, we also know that neuroligin 3 (NLG3), a post-synaptic protein that regulates transmission at the synapse, affects fruit fly social spacing. However, we do not know how those different parts of the neural circuitry are potentially integrated. We aim to elucidate the localization of NLG3 protein with respect to dopamine neurons and the MB, and to accurately identify where its expression is necessary to control proper social spacing. We will use an antibody against NLG3 protein in Drosophila brains and, through fluorescence microscopy, illuminate where neuroligin is expressed. NLG3-rich clusters will be the target of tissue-specific drivers of nlg3 RNAi for protein knockdown. Social space assays will quantify the behaviour of nlg3 RNAi fruit flies to determine the level of modification in spacing. Our results will suggest the necessary NLG3 expression required for standard social spacing behaviour in Drosophila.

P5. The effect of environmental stressors on Brown Marmorated Stink Bug (Halyomorpha halys) overwintering physiology John Ciancio, MSc Student

In temperate North America, insects spend a significant portion of their life overwintering, where

they encounter various environmental stressors including low temperatures, desiccation, and energy drain. The Brown Marmorated Stink Bug (Halyomorpha halys) is an invasive pest that damages several economically important crops - such as corn, soy, and apples - thus threatening the Canadian agricultural landscape. Here, we aim to determine the relative importance of low temperatures, desiccation, and energy drain in determining H. halys overwintering success, and to determine if H. halys stress tolerance changes seasonally. We placed groups of H. halys in a residential overwintering habitat, and conducted measurements of their tolerance of low temperatures, desiccation, and energy drain at three sampling points throughout the winter. Halyomorpha halys are chill-susceptible, and die at temperatures above their supercooling point (SCP; temperature at which internal ice formation begins). Their SCP does not change throughout winter, nor does water content or lipid and protein content; this suggests that desiccation stress and energy drain do not limit H. halys survival, while low temperatures may be a limiting factor. Female H. halys have significantly higher water content, and lipid and protein stores compared to males; however, this does not appear to enhance overwintering success because as only 39.7% of the surviving individuals were female. Overall, our study identifies potential strategies that aid in H. halys overwintering success, which may inform future pest managements strategies, and thus control future invasions of H. halys. P6. Can flies recover from social isolation? Ryley Yost, MSc Student

The social environment can affect behaviour by altering molecular processes and neuronal functioning. For example, in the fly Drosophila melanogaster social isolation affects complex behaviours including, aggression, courtship, mating, foraging, and learning and memory, as well as social spacing. Furthermore, changes in expression of many genes have been found, including in our lab for Drosophila Neuroligin 3 (dnlg3), a post-synaptic cell adhesion protein. The Neuroligin 3 protein ensures correct synaptic formation, maturation, and function, and the human homolog is a candidate gene for autism. In addition to having an expression modulated by social experience, mutations in dnlg3 lead to abnormal behavioural spacing in response to isolation. Social isolation does not only affect genes expression and behaviours such as social spacing. We also found that levels of dopamine, a neurotransmitter, levels are also altered. Of note, mutations in dopamine synthesis or signalling lead to abnormal social spacing too.

We want to better understand the effect of social experience on an animal, at those different levels. We propose here to assess whether the changes in social spacing, dNGL3 expression and dopamine levels resulting from social isolation can be reversed through exposure to a rich social environment.

P7. Examining the role of Cx43 in skull development. Sommer Jarvis, MSc Student

Connexins comprise a family of gap junctional proteins, which form intercellular channels that transport small molecules and secondary messengers between adjacent cells. Connexin proteins are prevalent in almost all organ systems throughout the human body. In particular, connexin proteins play a critical role in bone development, growth, and remodeling. Connexin43 (Cx43) is the most abundant connexin protein in bone, and is present in osteoblasts, osteocytes, and chondrocytes. The GJA1 gene encodes for Cx43, and primarily dominant mutations manifest phenotypically as oculodentodigital dysplasia (ODDD). Though ODDD affects several organ systems, it is most prominently characterized by skeletal dysmorphologies, particularly of the flat bones of the craniofacial skeleton. One such mutation expressed in humans results in the I130T amino acid substitution, for which a mouse model has been developed (Cx43I130T). Preliminary shape analyses in our lab using 3-month old Cx43I130T/+ littermates demonstrate that mutant mice display features characteristic of ODDD, including small facial bones and microcephaly. Additionally, we found that the anterior cranial base was significantly larger in mutants, and 30% of mutants possessed sub-mucous cleft palates. These results confirm that the Cx43I130T/+ mouse displays the ODDD phenotype, and suggests that disruption to Cx43 has an opposite effect on bones derived from intramembranous ossification (face and calvaria) and endochondral ossification (cranial base). Thus, it is hypothesized that Cx43I130T/+ mutant mice have a deregulated balance of differentiation and proliferation of osteoblasts and chondrocytes, which manifests phenotypically as craniofacial shape differences.

P8. Mite-y freeze-tolerant Susan Anthony, PhD Student

Freeze-tolerance, the ability to survive freezing of internal body fluids, is an adaptation that has been found in many insects. Thus far only one species of arachnid has been known to survive freezing: the scorpion Centruroides vittatus. However, we have discovered that a red velvet mite (Trombidium sp.), collected near London, Ontario, can also survive freezing during the winter (November - March). In winter, the average temperature at which the mites’ body fluids freeze ranges from -6.8 ± 0.2 C in November to -8.4 ± 0.2 C in January, and they survive to temperatures far below this value (between -17 and -24 C). During the winter, their hemolymph osmolality dramatically increases from 428 ± 28 mOsmol in November to 1025 ± 85 mOsmol in January, and the amount of glycerol, a known cryoprotectant, also increases. Outside of the winter months, although they freeze at similar temperatures (-7.7 ± 0.2 C, September), the mites do not survive this process. The mechanisms that underlie the red velvet mite’s ability to survive freezing are unknown.

P9. Nuclear genome assembly of the Antarctic psychrophilic green alga Chlamydomonas sp. UWO241 Xi Zhang, PhD Student

The Antarctic psychrophilic green alga Chlamydomonas sp. UWO241 is an emerging model for

studying microbial adaptation to polar environments with low temperatures (4°C– 6°C), low irradiance and high salt concentrations (700 mM). The green alga UWO241 genome sequencing data (Illumina Mi-Seq, Illumina Hi-Seq, Pacbio RSII raw reads, and Illumina RNA-Seq transcriptome) are all available though, little is known about its nuclear genome and its ability to survive in extreme environment such as cold adaptive ability. Here, based on the Ontario cloud computing service - Sharcnet and our lab server -SmithLab Server, a hybrid assembly workflow has been realized to assemble UWO241 genome. Then we focus on how genome sequence will help address important hypotheses with regards to psychrophily and genome evolution for the downstream analysis.

BGRF 2017 Organizing Committee

Chairperson

Jeff Martin

Finance Committee

Jessica Deakin

Joe Stinziano

Kevin Young

Outreach Committee

Amanda MacCannell

Trish Tully

Lauren Witterick

Programming Committee

Kim Mitchell

Carlie Muir

Nicholas Raun

Submissions Committee

Susan Anthony

Emily Clayton

Tosha Kelly

Danielle Spice

BGRF Art

Curtis Lubbe

BGRF would like to thank the following sponsors