Whirling Disease Whirling Disease (Myxobolus cerebralis) (Myxobolus cerebralis) Eric Stock Bio. 4800
Dec 31, 2015
Whirling DiseaseWhirling Disease(Myxobolus cerebralis)(Myxobolus cerebralis)
Eric StockBio. 4800
OutlineOutline
History
Distribution
Species Infected
Life Cycle
Breeding Resistance
Where did WD come from?Where did WD come from?
European Origin
First recorded in Germany (1903)
Introduced to the United States (1950s)
Now Worldwide distribution
World DistributionWorld Distribution
Canada???Canada???
Currently no literature reporting WD in Canada
Approaching Albertan and British Columbian Borders
Species Species SusceptibilitySusceptibility
0 = Resistant
1 = Partial Resistance
2 = Susceptible
3 = Highly Susceptible
S = Susceptibility unclear
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 Trout in AlbertaAlberta
Life CycleLife 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
1. Myxobolus cerebralis spore 2. Tubifex Worms
3. TAMs (Triactinomyxon) 4. Infected Trout
Parasite TransferParasite Transfer
Bird/Mammal Transfer?Bird/Mammal Transfer?
Myxospores have been found in digestive tract of piscivorous birds
Avian vector is still unclear
Myxobolus cerebralis is very specificTrout/salmon only
Fish eating mammals can’t be infected by the parasite
Eating fish will not infect YOU with WD
Breeding Resistance?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
ResultsResultsFor 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
ConclusionConclusion
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
ReferencesReferences 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/
WDResistantTroutBroodstock.htm http://www.srd.alberta.ca/BiodiversityStewardship/WildSpecies/
Fish/Default.aspx http://www.thebowriver.com/whirling_disease_tu.htm http://www.tu.org/whirling-disease
Questions?Questions?
Be Nice!