Title: Functional genetic diversity and pathogen resistance in blacktailed prairie dogs
1Functional genetic diversityand pathogen
resistancein black-tailed prairie dogs
Genes, germs, and prairie dogs
- Liz Harp
- Colorado State University
- Graduate Degree Program in Ecology
- AAVP Meeting July 2008
2Objective
- Compare parasite species richness and numbers of
parasites to genetic diversity in 4 immune system
genes and 10 microsatellite loci in black-tailed
prairie dogs - Use this information to
- Identify relationships between immunogenetic
diversity and parasite numbers and diversity - Compare neutral vs. functional genetic markers
for use in conservation management
3Motivation and brief background parasites
- Parasites are important in wildlife conservation
- Rarely cause extinction directly, but
- May help maintain genetic variation
- Parasites are rarely considered inwildlife
conservation plans unless they are obviously
impacting a population
4Motivation and brief background genetics
- Conservation genetic markers typically neutral
- Microsatellites, SNPs (good for population
genetics) - Functional markers might be better for monitoring
populations breeding programs - Immune system genes,
- Lots of recent research with MHC diversity
- But what about other functional genetic markers?
Major Histocompatibility Complex An important
part of the adaptive immune system More on this
later
5Motivation and brief background prairie dogs
- Social burrowing rodents in the squirrel family
- Abundant in eastern Colorado
- Plague outbreaks are common
- They have a lot of parasites, sort of
- Five prairie dog species
- One threatened, one endangered,others frequently
petitioned for listing
6Black-tailed prairie dog parasites(a subsample)
- Ectoparasites
- Oropsylla hirsuta
- Oropsylla tuberculata
- Pulex simulans
- Thrassis fotus
- Ornithodoros turicata
- Gastrointestinal parasites
- Eimeria (4 species expected)
- Giardia
- Cryptosporidium
- Microparasites (antibodies)
- Yersinia pestis (gram negative bacterium)
- West Nile Virus (single stranded RNA virus)
7Eimeria recorded from black-tailed prairie dogs
- E. beecheyi (Casper, WY)
- E. callospermophili (Casper, WY)
- E. cynomysis (northern Colorado)
- E. lateralis (N. Colorado SW North Dakota
Casper, WY) - E. ludoviciani (N. Colorado SW North Dakota)
- E. morainensis (Casper, WY)
- E. pseudospermophili (Casper, WY)
- E. spermophili (Casper, WY)
- E. vilasi (Casper, WY)
Names corrected from original sources according
to Wilbur et al. 1998
8Hypothesis
- Specific alleles in immune system genes will
provide some level of resistance to particular
parasites or groups of parasites
9Immune genes of interest
- Toll-like receptors 2 4
- Pattern recognition molecules
- Found on dendritic cells, macrophages, and
neutrophils - Viruses, bacteria, protozoa, fungi, and
helminths (TLR 2)
10Immune genes of interest
- Toll-like receptors 2 4
- Chemokine receptor 5
- Found on dendritic cells, macrophages, and CD4 T
cells - Involved in immune cell chemotaxis
- Used by HIV to gain entry to target cells
- Hypothesized link to plague immunity
11Immune genes of interest
- Toll-like receptors 2 4
- Chemokine receptor 5
- Class II Major Histocompatibility Complex DRB-1
- Highly polymorphic
- Found on dendritic cells, macrophages, and B
cells - Presents extracellular antigens to helper T cells
- Many studies using a variety of wild vertebrates
- Parasites, demographic history,
mate-choice,selection mechanisms
12Field methods
- Short Grass Steppe Long Term Ecological Research
Area (Pawnee National Grassland) - Three prairie dog colonies
Avg dispersal distance 1.8 2.7km Max dispersal
distance 5.7 9.6km
13Field methods
- Pawnee National Grassland
- Live-trap black-tailed prairie dogs
- June November 2007 April November 2008
14Field methods
- Pawnee National Grassland
- Live-trap black-tailed prairie dogs
- Collect fleas, feces, blood, and tissue
15Field methods
- Pawnee National Grassland
- Live-trap black-tailed prairie dogs
- Collect fleas, feces, blood, and tissue
- Record age, sex, and weight
16Field methods
- Pawnee National Grassland
- Live-trap black-tailedprairie dogs
- Collect fleas, feces,blood, and tissue
- Record age, sex, and weight
- Mark each animal with numbered ear tags
17Capture Recordsthrough July 14, 2007
18Laboratory methods
- Quantify and identify
- Eimeria spp.
- Cryptosporidium and Giardia
- Fleas and ticks
- Test for antibodies to
- West Nile Virus
- Yersinia pestis (plague)
- SSCP analysis to determine immune gene alleles
- Microsatellite analysis
- Neutral control, relatedness
19Anticipated results(i.e., why this research is
important)
- Develop adaptive genetic markers that will be
useful in conservation for all 5 species of
prairie dog - Contribute to current knowledge of the genetic
basis for susceptibility and resistance to
disease - Provide a current survey of black-tailed prairie
dog parasites on the Pawnee National Grassland
20Invaluable help, advice, and funding
- Mike Antolin
- Lora Ballweber
- Dan Tripp
- Shelley Bayard de Volo
- Chris Symmes
- Sarah ONeil
- Funding
- National Science Foundation
- Sigma Xi
- American Society of Mammalogists
- Students and Volunteers (field)
- Allison Fockler, Alyssa Christ, Heather Craven,
Holly Meltesen, Janelle Trujillo, Jennie Skinner,
Kelsey Toth, Marie Stiles, Nicole McDaniel, Paul
Stearman, Rebecca Blaskovich, Sarah Legare, Sarah
ONeil, Sean Streich, Sorrell Redford, Tori
Wheeler, Tyler Tretten, and all of the ecology
students and teachers who came out for a few days
to see what we do out there - Students and Volunteers (lab)
- Alex Ard, Helen Lepper, Jen Austin, Sarah Legare,
Sarah ONeil
All photos were either taken by me, my students,
or other people I know, or are from WikiMedia
Commons.
21Questions? Comments?