Tag: Poster 62

Do Progenitor Subpopulations Contribute to Zebrafish Enteric Nervous System Development?

Presenter: Charlotte Taylor

Mentors: Judith Eisen and Julia Ganz, Biology

Poster: 62

Major: Biochemistry 

The enteric nervous system (ENS) provides intrinsic intestinal innervation and modulates intestinal function. The ENS forms a complex network of neuronal and glial subtypes. ENS progenitors that give rise to this network express different marker genes, e.g. phox2b, sox10, and ret. Using the zebrafish model, we investigated whether expression of these markers defines distinct ENS progenitor subpopulations. Gene expression revealed subpopulations, the most prominent of which are characterized by the following combinations: phox2b; phox2b/ret; phox2b/sox10; phox2b/ret/sox10. We will now determine whether these distinct progenitors have functional significance for ENS development. We will use the Cre/loxP lineage tracing system to track progeny of distinct progenitor subpopulations and determine if they give rise to different ENS cell types. Using BAC-recombineering, we will generate BAC- constructs that drive Cre recombinase expression under enteric progenitor specific promoters (e.g. ret). To test if BAC enteric progenitor promoter sequences drive expression faithfully, we are generating BAC-constructs that drive expression of green fluorescent proteins (GFP). We are currently analyzing ENS GFP expression of a modified ret BAC. After generating Cre-constructs, we will inject them into a reporter line and identify progeny of labeled progenitors at different times during ENS development. Our results will provide a comprehensive lineage analysis of ENS precursors in vivo and thus offer new insights into ENS development and the potential of individual ENS precursors.

Investigating the Fuction of a Novel Gene in Heart Valve Development

Presenter: Thomas Forman

Faculty Mentor: Fernanda M. Bosada, Kryn Stankunas

Presentation Type: Poster 62

Primary Research Area: Science

Major: Biology, Human Physiology

Funding Source: Huestis-McLean Memorial Scholarship Recipient, $450; Apex Scholarship, University of Oregon, $1000 per term

Congenital valve disease affects at least two percent of the world’s population, a remarkable frequency that underlines the urgent need to understand the etiology of these common birth defects. These underlying abnormalities may originate from disruption of embryonic valve development. Primordial heart valves proceed through complex signaling events to form thin, elongated leaflets/cusps. However, the roles of many of these signaling pathways in valve development remain incompletely understood. Previous research indicates that Receptor Tyrosine Kinase (RTK) signaling, commonly involved in cell proliferation, is activated during valve mesenchyme expansion. We found that Lrig1, an RTK negative regulator, is dynamically expressed in the valves throughout development. We observed high expression in the endocardium of the atrioventricular canal (AVC) during the first steps of valve development. During valve mesenchyme expansion and elongation, we detected Lrig1 at the distal end of both the AVC and semilunar (SL) valves. Using a transgenic mouse line to knock out Lrig1 function, we demonstrated that homozygous Lrig1 embryos have hypertrophic AVC valves, although we observed no such defect in the SL valves. Interestingly, mutant AVC valves are not overproliferative at 13.5 days post-fertilization. We hypothesize that Lrig1 negatively regulates endocardial-to-mesenchymal transformation (EMT) in early valve development. Fate-mapping of Lrig1+ cells will further elucidate the roles of Lrig1. Our findings are the first ever to describe a function for Lrig1 in the heart valves.

Inflammation as a Mediator of Depression and Diabetes in the Study on global AGEing and adult health (SAGE)

Presenter(s): Allison Dona − General Science, Spanish

Faculty Mentor(s): Josh Snodgrass, Alicia DeLouize

Poster 62

Research Area: Natural Science

Funding: NIH NIA Interagency Agreement; Ministry of Health in Mexico; University of Oregon Bray Fellowship

Diabetes and depression are major global health concerns, affecting over 400 million and 300 million worldwide, respectively. Numerous studies have found that these diseases are commonly comorbid, suggesting the possibility of an underlying shared physiological process such as an inflammatory pathway. As a biomarker of inflammation, C-reactive protein (CRP) has not been consistently linked to these conditions, despite the fact that diabetes and depression have both been linked to inflammatory mechanisms. This study uses Mexico Wave 1 data from the Study on global AGEing and adult health (SAGE) to examine if CRP mediates the relationship between depression and diabetes risk. It is hypothesized that, in participants 50-plus, inflammation will mediate the effect between the two conditions. Depression was estimated using a behavior-based diagnostic algorithm, inflammation was assessed using dried blood spot (DBS) CRP, and diabetes risk was assessed using DBS glycated hemoglobin (HbA1c). The association between depression and diabetes risk was partially mediated by inflammation. The presence of depression is associated with increased CRP, which is associated with increased HbA1c. This suggests that inflammation may be associated with the comorbidity of depression and diabetes. This may be the first study to use a large sample of older adults in a middle-income nation with high-resolution biomarker information to investigate physiological processes that might be involved in both conditions, an understanding of which could lead to better treatments.

Grooming as an Indicator of Male Dominance and Reconciliation in Japanese Macaques (Macaca fuscata)

Presenter(s): Caitlin Shreeve

Co Presenter(s): Nichole Biggs

Faculty Mentor(s): Frances White & Kylen Gartland

Poster 62

Session: Sciences

In primate societies, social rank is very important in males. Higher-ranking males get more food, more mates, and better social situations than lower-ranking males. Males, therefore, fight over rank and as a result, often need to “make-up” or reconcile after a fight. This reconciliation is important for repairing social bonds and group cohesion. Dominance rank is primarily determined by primatologists from watching aggressive interactions, but if fights are rare it can be hard to identify male rank. In this study, we will be researching whether it is possible to use a more common behavior to identify male rank. Japanese macaques (Macaca fuscata) spend a lot of time grooming, which is used to rebuild and strengthen bonds within the social group. The directionality of grooming may be indicative of dominance relationships because high-ranking individuals may receive more grooming than low ranking individuals. Additionally, reconciliation through social grooming may also be related to the dominance rank of the males involved. Through an examination of published studies, we will extract information on the relationship between grooming and reconciliation with dominance rank. We will then develop a data collection methodology which we will use in a research study of the adult males in the Japanese macaque group at the Oregon National Primate Research Center. Studies of reconciliation and dominance rank through the lens of grooming behaviors can give us a better understanding of the complex social relationships in multi-male Japanese macaque societies.