1. Whirling Disease (Myxobolus cerebralis) Eric Stock Bio. 4800

2. Outline History Distribution Species Infected Life Cycle Breeding Resistance

3. Where did WD come from? European Origin First recorded in Germany (1903) Introduced to the United States (1950s) Now Worldwide distribution

4. World Distribution

6. Canada??? Currently no literature reporting WD in Canada Approaching Albertan and British Columbian Borders

7. Species Susceptibility 0 = Resistant 1 = Partial Resistance 2 = Susceptible 3 = Highly Susceptible S = Susceptibility unclear

8. Native to Alberta Non-native Species Bull Trout Cutthroat Trout Lake Trout Rainbow Trout Brook Trout (Eastern Canada) 1903 Brown Trout (Europe/Asia) 1924 Golden Trout (California) 1959 Trout in Alberta

9. Life Cycle Primary Host = Trout/Salmon Secondary Host = Tubifex Worms TAM = infective stage Spores can survive 20-30 years in mud Juveniles less than 5 months = most susceptible

10. 1. Myxobolus cerebralis spore2. Tubifex Worms 3. TAMs (Triactinomyxon) 4. Infected Trout

12. Parasite Transfer

13. Bird/Mammal Transfer? Myxospores have been found in digestive tract of piscivorous birds Avian vector is still unclear Myxobolus cerebralis is very specific Trout/salmon only Fish eating mammals can’t be infected by the parasite Eating fish will not infect YOU with WD

14. Breeding Resistance? Microarray analysis – examined expression changes in resistant and susceptible strains of rainbow trout after exposure to M. cerebralis Hatchery rainbow trout from Germany (Hofer strain) Acquired a degree of resistance to whirling disease Higher than any domestic rainbow strains Comparable to that of brown trout Native to Europe (asymptomatic) to WD Susceptible rainbow trout (US) Trout Lodge

15. Results For both the resistant Hofer and susceptible Trout Lodge rainbow trout strains: Response to infection linked with the interferon system Metallothionein B was differentially expressed between the resistant and susceptible strains A good candidate for future whirling disease resistance studies

16. Conclusion The identified genes have allowed insight into trout’s immune response and resistance to whirling disease infection. Additional studies crossed the resistant Hofer strain with a susceptible CRR strain (Colorado River rainbow trout ) Resistance to whirling disease was inherited by offspring Management: to re-establish trout in areas affected by WD

17. References Baerwald, M.R, Welsh, A.B, Hedrick, R.P, May. B. 2008. Discovery of genes implicated in whirling disease infection and resistance in rainbow trout using genome-wide expression profiling. BMC Genomics. 9: 1471- 1482 Gilbert, M.A, Granath, W.O. 2003. Whirling Disease of Salmonid Fish: Life Cycle, Biology, and Disease. The Journal of Parasitology. 89: 658-667 http://berryns.wordpress.com/2010/01/27/whirling-disease/ http://whirlingdisease.montana.edu/default.asp http://wildlife.state.co.us/Research/Aquatic/WhirlingDisease/WDR esistantTroutBroodstock.htm http://wildlife.state.co.us/Research/Aquatic/WhirlingDisease/WDR esistantTroutBroodstock.htm http://www.srd.alberta.ca/BiodiversityStewardship/WildSpecies/Fi sh/Default.aspx http://www.srd.alberta.ca/BiodiversityStewardship/WildSpecies/Fi sh/Default.aspx http://www.thebowriver.com/whirling_disease_tu.htm http://www.tu.org/whirling-disease

18. Questions? Be Nice!