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The Immunological Basis for Disease Dilution Sheena Wheeler Dr. Anna Jolles

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Many human diseases are transmitted from non-human animals (Zoonotic diseases) Many human diseases are transmitted from non-human animals (Zoonotic diseases) Some species are better at transmitting diseases than others Some species are better at transmitting diseases than others Biodiversity is important to ecosystem services Biodiversity is important to ecosystem services RELEVANCE

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BACKGROUND Disease Dilution: Empirical Findings high biodiversity = reduced risk of disease low biodiversity = increased risk of disease Sin Nombre Virus in Deer Mice (Laurie J. Dizney)

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BACKGROUND BIODIVERSITY = = DISEASE Why is the deer mouse good at transmitting disease?

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HYPOTHESIS We hypothesize that short-lived species invest less in certain aspects of their immune system, which may make them better at transmitting diseases. Ex:VS.

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MY OBJECTIVE To examine the immune differences between short-lived and long-lived rodent species

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METHODS: FIELD 1.Trap different rodent species throughout Oregon (Sherman and Tomahawk traps) 2.Collect blood, feces, and ectoparasites from each rodent 3.Ear tag, measure, weigh and release

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TRAPPING LOCATIONS 1.Local 2.Rogue River- Siskiyou National Forest 3.Willamette National Forest 4.Steens Mountain Eastern OR

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MY OBJECTIVE To examine the immune differences between short-lived and long-lived rodent species 1.Determine the differences in white blood cell composition between rodent species.

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BACKGROUND White blood cells (WBC): travel in bloodstream to infected areas and destroy responsible bacteria Complete Blood Count: Determine numbers and types of white blood cells (WBC) in an animal Good general way to see how the immune system of an animal functions WBC BACTERIA

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METHODS: LAB 1.Perform complete blood counts (CBC) on each rodent: A) White blood cell counts B) Cell differentiation Lymphocyte Neutrophil Band Monocyte Eosinophil Basophil

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MY OBJECTIVE Examine the immune differences between short- lived and long-lived rodent species 1.Determine the differences in blood cell composition between rodent species. 2.Evaluate the health of different rodent species via fecal parasite analysis.

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METHODS: LAB 1. Fecal Float to examine the types of parasite eggs 2. Fecal McMasters to count the different parasite eggs within the feces

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PICTURES

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PRELIMINARY RESULTS Table 1: Average and standard deviation of total white blood cells/l for six species of rodents. 1. Complete Blood Counts SpeciesSample SizeAverage WBC/lSt. Dev. WBC California Ground Squirrel1010234.576270.63 Chipmunk38666.67 Dusky Footed Woodrat98812.52863.89 Norway Rat83581.113821.13 Black Rat29527.782710.58 Deer Mouse793488.482360.07

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PRELIMINARY RESULTS Table 2: Percent of species with fecal parasites and percent of each type of parasite in each species. 2. Fecal Analysis SpeciesSample Size Fecal ParasitesCoccidiaCapillariaOther California Ground Squirrel1080.00% 10.00%70.00% Chipmunk3100% 0% Dusky Footed Woodrat9100.00% 75.00%0.00% Norway Rat850.00%67.00%33.00%0.00% Deer Mouse7925.53%21.28%0.00%0.02% Pinyon Mouse4100.00%33.00%0.00%67.00%

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WHATS NEXT? Continue data collection of rodents around Oregon Trap larger/longer lived rodents (beaver, nutria) Analyze data

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ACKNOWLEDGEMENTS Howard Hughes Medical Institute (HHMI) Undergraduate Research, Innovation, Scholarship and Creativity(URISC) Dr. Anna Jolles Dr. Rhea Hanselmann Dr. Kevin Ahern