Tag: Poster 53

Prehistoric Human Adaptations to Climate Change?: An ArcGIS Analysis of Northern Side-notched Projectile Points in the Northern Great Basin

Presenter: Jordan Pratt

Mentor: Patrick O’Grady, Museum of Natural and Cultural History

Poster: 53

Major: Anthropology

Climate change dramatically transforms the ecological zones that humans call home. Historically there have been many global warming periods, including the Pleistocene-Holocene transition, during which humans were forced to adapt to a loss of water and biotic diversity. The northern Great Basin region of eastern Oregon, provides an ideal case in which to study human adaptation to climate change. In this region, the Pleistocene-Holocene transition was followed by multiple smaller shifts in climate. The early middle Holocene of around 8,000 calendar years before present provided one of these warming periods, in which the local environment became much drier and more arid. Northern Side-notched points, a type of dart point, date to ca 7,000-4,000 cal. BP, and are one of the few pieces of material culture that have reliably been dated to the early middle Holocene in the northern Great Basin. Analysis of Northern Side-notched points collected by the Burn’s Bureau of Land Management District and UO Museum of Natural and Cultural History’s Archaeological Field School will be used to establish a more concrete means of classification for these projectile points, especially those being found in eastern Oregon. Then ArcGIS will be used to geospatially analyze the distribution of the projectile points throughout the Burn’s BLM District compared to known obsidian sources. By analyzing the distribution of projectile points and movement of materials across the landscape, insights can be made into prehistoric trade mobility and settlement patterns which may indicate human adaptions to environmental change.

Pheromones and Path Selection of Atta. Cephalotes

Presenter: Joshua Coon

Faculty Mentor: Robert Schofield

Presentation Type: Poster 53

Primary Research Area: Science

Major: Biology

Funding Source: McNair Scholar, University of Oregon $3,500

Atta cephalotes has been studied widely for their use of pheromones in terms of foraging trail choice, however there is a lack of research in terms of energetically successful trail choice. According to the current methodology, once a trail is established there is no way for a new trail to become established, even if energetically favored. I propose that pheromones play a role in controlling the preference for a foraging trail that is shorter and consumes less energy. Looking for differences in leaf carrying and non-leaf carrying ants, when given a new path to walk along. Using Teflon tubing to collect the pheromones laid down by each group of ants in two separate scenarios allowed for a clean rinse after collection. The samples were then analyzed using a coupled gas chromatographer and mass spectrometer (GC-MS), using a split method. Preliminary results show a lack of sensitivity of the machine which is necessary for the detection of minuscule analyte quantities. Attempting to counteract the poor sensitivity new optimization methods of collection for obtaining a higher amount of analyte. Including the new preliminary data with optimized collection methods we can begin to piece together new hypothesis about pheromonal control switches using energetic theory.

Life With White Blood: Histological Analysis of Antarctic Icefish Elucidates its Unique Adaptation to Loss of Hemoglobin, Fueling Inquir into The Regulatory Role Of Mirnas in Hematopoiesis

Presenter(s): Leandro Marx − Biology

Faculty Mentor(s): Thomas Desvignes, John Postlethwait

Poster 53

Research Area: Biology

Funding: University of Oregon Presidential Scholarship, National Science Foundation

Antarctic icefish (Channichthyidae), belong to a family of ray-finned fish endemic to the Southern Ocean (1). With an astonishing set of adaptations, the enigmatic icefish have inspired curiosity since their discovery in 1927 (2). The defining feature of this 16-species family is their “white blood”, which is devoid of hemoglobin — the iron-containing protein that facilitates oxygen transport throughout the body (3,4). Through a series of histological analyses, genetic analyses, and reverse genetic screens, the aim of this research is to identify phenotypic and genotypic adaptations that mitigate the consequences of the unique physiology of the icefish as well as to understand the role of miRNAs (small, regulatory RNA molecules) in red blood cell production (hematopoiesis). Current questions focus primarily on the regulatory role of miRNAs in hematopoiesis. Through differential analysis of miRNA expression between icefish and other ray-finned species, we will select candidate genes that may be involved in the hematopoietic process. Using these target miRNAs, we will generate genetic knockouts in zebrafish using the CRISPR/Cas-9 system and will observe the effects of these genes on hematopoiesis. Although work is currently in progress, successful completion of this research will develop a greater understanding of the unique physiology of icefish and the role of understudied miRNAs in the genetic regulation of hematopoiesis. In addition to helping us understand the evolution of developmental mechanisms, results may be relevant to human anemia diseases because miRNAs circulating in the bloodstream are thought to be potential disease therapies (5).

Investigating amino acid-modulated motility of the zebrafish bacterial isolate, Aeromonas veronii

Presenter(s): Emily Ma

Faculty Mentor(s): Cathy Robinson & Karen Guillemin

Poster 53

Session: Sciences

Animals are colonized by communities of microorganisms that influence the health and development of their host. However, the mechanisms of host colonization are still underexplored. To investigate this, previous work in the lab used experimental evolution to adapt a bacterial symbiont, Aeromonas, to the zebrafish gut. These experiments led to the identification of a novel gene, spdE, which significantly impacts host colonization. We found that evolved isolates with mutations in spdE had faster rates of motility and increased host immigration. Sequence analysis revealed that the protein, SpdE, has a domain for sensing extracellular signals and a diguanylate cyclase domain which produces an intercellular signaling molecule that regulates motility. Further biochemical investigation identified that the signal SpdE senses is hydrophobic amino acids, specifically proline, valine, and isoleucine. To further investigate the relationship between SpdE-dependent Aeromonas motility and environmental amino acids, we developed a new technique (“exploration assay”) which is designed to measure differences in motility between strains or conditions. Using the exploration assay, we compared motility of wild type and spdE knockout strains in different amino acid environments. From our results, we found that the wild type strain is more motile in the presence of these amino acids. However, even in the absence of amino acid signal, the spdE knockout is more motile than the wild type. From these data, we have created a model for how SpdE regulates motility in response to amino acids which offers novel insights into Aeromonas biology and the mechanisms of host colonization.